Conditionally declare and define variable that is unused in LITE mode (#9854)

Summary:
Context:
As mentioned in https://github.com/facebook/rocksdb/issues/9701, we have the following in LITE=1 make static_lib for v7.0.2
```
  CC       file/sequence_file_reader.o
  CC       file/sst_file_manager_impl.o
  CC       file/writable_file_writer.o
In file included from file/writable_file_writer.cc:10:
./file/writable_file_writer.h:163:15: error: private field 'temperature_' is not used [-Werror,-Wunused-private-field]
  Temperature temperature_;
              ^
1 error generated.
make: *** [file/writable_file_writer.o] Error 1
```

 as titled

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9854

Test Plan:
- Local `LITE=1 make static_lib` reveals the same error and error is gone after this fix
- CI

Reviewed By: ajkr, jay-zhuang

Differential Revision: D35706585

Pulled By: hx235

fbshipit-source-id: 7743310298231ad6866304ffa2225c8abdc91d9a

.travis.yml

@@ -43,7 +43,6 @@ env:
   - JOB_NAME=cmake-gcc9 # 3-5 minutes
   - JOB_NAME=cmake-gcc9-c++20 # 3-5 minutes
   - JOB_NAME=cmake-mingw # 3 minutes
-  - JOB_NAME=status_checked
 
 matrix:
   exclude:
@@ -58,10 +57,6 @@ matrix:
     env: JOB_NAME=cmake-mingw
   - os: linux
     compiler: clang
-  - if: type = pull_request AND commit_message !~ /FULL_CI/
-    os: linux
-    arch: s390x # Temporary while working through gcc-7 + assembler issue
-    env: TEST_GROUP=platform_dependent
   - if: type = pull_request AND commit_message !~ /FULL_CI/
     os: linux
     arch: arm64
@@ -190,18 +185,6 @@ matrix:
     os: linux
     arch: s390x
     env: JOB_NAME=cmake-gcc9-c++20
-  - if: type = pull_request AND commit_message !~ /FULL_CI/
-    os : linux
-    arch: arm64
-    env: JOB_NAME=status_checked
-  - if: type = pull_request AND commit_message !~ /FULL_CI/
-    os: linux
-    arch: ppc64le
-    env: JOB_NAME=status_checked
-  - if: type = pull_request AND commit_message !~ /FULL_CI/
-    os: linux
-    arch: s390x
-    env: JOB_NAME=status_checked
 
 install:
   -  CC=gcc-7 && CXX=g++-7
@@ -247,21 +230,25 @@ before_script:
 script:
   - date; ${CXX} --version
   - if [ `command -v ccache` ]; then ccache -C; fi
+  - export MK_PARALLEL=4;
+    if [[ "$TRAVIS_CPU_ARCH" == s390x ]]; then
+      export MK_PARALLEL=1;
+    fi
   - case $TEST_GROUP in
     platform_dependent)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=only make -j4 all_but_some_tests check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=only make -j$MK_PARALLEL all_but_some_tests check_some
       ;;
     1)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_END=backupable_db_test make -j4 check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_END=backupable_db_test make -j$MK_PARALLEL check_some
       ;;
     2)
-      OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 make -j4 tools && OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=backupable_db_test ROCKSDBTESTS_END=db_universal_compaction_test make -j4 check_some
+      OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 make -j$MK_PARALLEL tools && OPT="-DTRAVIS -DROCKSDB_NAMESPACE=alternative_rocksdb_ns" LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=backupable_db_test ROCKSDBTESTS_END=db_universal_compaction_test make -j$MK_PARALLEL check_some
       ;;
     3)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=db_universal_compaction_test ROCKSDBTESTS_END=table_properties_collector_test make -j4 check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=db_universal_compaction_test ROCKSDBTESTS_END=table_properties_collector_test make -j$MK_PARALLEL check_some
       ;;
     4)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=table_properties_collector_test make -j4 check_some
+      OPT=-DTRAVIS LIB_MODE=shared V=1 ROCKSDBTESTS_PLATFORM_DEPENDENT=exclude ROCKSDBTESTS_START=table_properties_collector_test make -j$MK_PARALLEL check_some
       ;;
     esac
   - case $JOB_NAME in
@@ -269,10 +256,10 @@ script:
       OPT=-DTRAVIS LIB_MODE=shared V=1 make rocksdbjava jtest
       ;;
     lite_build)
-      OPT='-DTRAVIS -DROCKSDB_LITE' LIB_MODE=shared V=1 make -j4 all
+      OPT='-DTRAVIS -DROCKSDB_LITE' LIB_MODE=shared V=1 make -j$MK_PARALLEL all
       ;;
     examples)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 make -j4 static_lib && cd examples && make -j4
+      OPT=-DTRAVIS LIB_MODE=shared V=1 make -j$MK_PARALLEL static_lib && cd examples && make -j$MK_PARALLEL
       ;;
     cmake-mingw)
       sudo update-alternatives --set x86_64-w64-mingw32-g++ /usr/bin/x86_64-w64-mingw32-g++-posix;
@@ -285,10 +272,7 @@ script:
           ;;
       esac
 
-      mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=0 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 .. && make -j4 && cd  .. && rm -rf build && mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release $OPT && make -j4 rocksdb rocksdbjni
-      ;;
-    status_checked)
-      OPT=-DTRAVIS LIB_MODE=shared V=1 ASSERT_STATUS_CHECKED=1 make -j4 check_some
+      mkdir build && cd build && cmake -DCMAKE_BUILD_TYPE=Release -DWITH_TESTS=0 -DWITH_GFLAGS=0 -DWITH_BENCHMARK_TOOLS=0 -DWITH_TOOLS=0 -DWITH_CORE_TOOLS=1 .. && make -j$MK_PARALLEL && cd  .. && rm -rf build && mkdir build && cd build && cmake -DJNI=1 .. -DCMAKE_BUILD_TYPE=Release $OPT && make -j$MK_PARALLEL rocksdb rocksdbjni
       ;;
     esac
 notifications:

CMakeLists.txt

@@ -321,7 +321,8 @@ if(NOT MSVC)
   set(CMAKE_REQUIRED_FLAGS "-msse4.2 -mpclmul")
 endif()
 
-CHECK_CXX_SOURCE_COMPILES("
+if (NOT PORTABLE OR FORCE_SSE42)
+  CHECK_CXX_SOURCE_COMPILES("
 #include <cstdint>
 #include <nmmintrin.h>
 #include <wmmintrin.h>
@@ -333,11 +334,12 @@ int main() {
   auto d = _mm_cvtsi128_si64(c);
 }
 " HAVE_SSE42)
-if(HAVE_SSE42)
-  add_definitions(-DHAVE_SSE42)
-  add_definitions(-DHAVE_PCLMUL)
-elseif(FORCE_SSE42)
-  message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
+  if(HAVE_SSE42)
+    add_definitions(-DHAVE_SSE42)
+    add_definitions(-DHAVE_PCLMUL)
+  elseif(FORCE_SSE42)
+    message(FATAL_ERROR "FORCE_SSE42=ON but unable to compile with SSE4.2 enabled")
+  endif()
 endif()
 
 # Check if -latomic is required or not

HISTORY.md

@@ -1,5 +1,31 @@
 # Rocksdb Change Log
-## Unreleased
+## 7.0.4 (03/29/2022)
+### Bug Fixes
+* Fixed a race condition when disable and re-enable manual compaction.
+* Fixed a race condition for `alive_log_files_` in non-two-write-queues mode. The race is between the write_thread_ in WriteToWAL() and another thread executing `FindObsoleteFiles()`. The race condition will be caught if `__glibcxx_requires_nonempty` is enabled.
+* Fixed a race condition when mmaping a WritableFile on POSIX.
+* Fixed a race condition when 2PC is disabled and WAL tracking in the MANIFEST is enabled. The race condition is between two background flush threads trying to install flush results, causing a WAL deletion not tracked in the MANIFEST. A future DB open may fail.
+* Fixed a heap use-after-free race with DropColumnFamily.
+* Fixed a bug that `rocksdb.read.block.compaction.micros` cannot track compaction stats (#9722).
+
+## 7.0.3 (03/23/2022)
+### Bug Fixes
+* Fixed a major performance bug in which Bloom filters generated by pre-7.0 releases are not read by early 7.0.x releases (and vice-versa) due to changes to FilterPolicy::Name() in #9590. This can severely impact read performance and read I/O on upgrade or downgrade with existing DB, but not data correctness.
+* Fixed a bug that `Iterator::Refresh()` reads stale keys after DeleteRange() performed.
+
+### Public API changes
+* Added pure virtual FilterPolicy::CompatibilityName(), which is needed for fixing major performance bug involving FilterPolicy naming in SST metadata without affecting Customizable aspect of FilterPolicy. For source code, this change only affects those with their own custom or wrapper FilterPolicy classes, but does break compiled library binary compatibility in a patch release.
+
+## 7.0.2 (03/12/2022)
+* Fixed a bug that DisableManualCompaction may assert when disable an unscheduled manual compaction.
+
+## 7.0.1 (03/02/2022)
+### Bug Fixes
+* Fix a race condition when cancel manual compaction with `DisableManualCompaction`. Also DB close can cancel the manual compaction thread.
+* Fixed a data race on `versions_` between `DBImpl::ResumeImpl()` and threads waiting for recovery to complete (#9496)
+* Fixed a bug caused by race among flush, incoming writes and taking snapshots. Queries to snapshots created with these race condition can return incorrect result, e.g. resurfacing deleted data.
+
+## 7.0.0 (02/20/2022)
 ### Bug Fixes
 * Fixed a major bug in which batched MultiGet could return old values for keys deleted by DeleteRange when memtable Bloom filter is enabled (memtable_prefix_bloom_size_ratio > 0). (The fix includes a substantial MultiGet performance improvement in the unusual case of both memtable_whole_key_filtering and prefix_extractor.)
 * Fixed more cases of EventListener::OnTableFileCreated called with OK status, file_size==0, and no SST file kept. Now the status is Aborted.

Makefile

@@ -329,8 +329,8 @@ ifneq ($(MACHINE), arm64)
 # linking with jemalloc (as it won't be arm64-compatible) and remove some other options
 # set during platform detection
 DISABLE_JEMALLOC=1
-PLATFORM_CFLAGS := $(filter-out -march=native -DHAVE_SSE42, $(PLATFORM_CFLAGS))
-PLATFORM_CXXFLAGS := $(filter-out -march=native -DHAVE_SSE42, $(PLATFORM_CXXFLAGS))
+PLATFORM_CFLAGS := $(filter-out -march=native -DHAVE_SSE42 -DHAVE_AVX2, $(PLATFORM_CFLAGS))
+PLATFORM_CXXFLAGS := $(filter-out -march=native -DHAVE_SSE42 -DHAVE_AVX2, $(PLATFORM_CXXFLAGS))
 endif
 endif
 endif
@@ -2098,7 +2098,7 @@ SHA256_CMD = sha256sum
 
 ZLIB_VER ?= 1.2.11
 ZLIB_SHA256 ?= c3e5e9fdd5004dcb542feda5ee4f0ff0744628baf8ed2dd5d66f8ca1197cb1a1
-ZLIB_DOWNLOAD_BASE ?= http://zlib.net
+ZLIB_DOWNLOAD_BASE ?= https://zlib.net/fossils
 BZIP2_VER ?= 1.0.8
 BZIP2_SHA256 ?= ab5a03176ee106d3f0fa90e381da478ddae405918153cca248e682cd0c4a2269
 BZIP2_DOWNLOAD_BASE ?= http://sourceware.org/pub/bzip2
@@ -2116,7 +2116,9 @@ CURL_SSL_OPTS ?= --tlsv1
 ifeq ($(PLATFORM), OS_MACOSX)
 ifeq (,$(findstring librocksdbjni-osx,$(ROCKSDBJNILIB)))
 ifeq ($(MACHINE),arm64)
-	ROCKSDBJNILIB = librocksdbjni-osx-aarch64.jnilib
+	ROCKSDBJNILIB = librocksdbjni-osx-arm64.jnilib
+else ifeq ($(MACHINE),x86_64)
+	ROCKSDBJNILIB = librocksdbjni-osx-x86_64.jnilib
 else
 	ROCKSDBJNILIB = librocksdbjni-osx.jnilib
 endif
@@ -2247,15 +2249,20 @@ endif
 	$(MAKE) rocksdbjavastatic_deps
 	$(MAKE) rocksdbjavastatic_libobjects
 	$(MAKE) rocksdbjavastatic_javalib
-	$(MAKE) rocksdbjavastatic_jar
+	$(MAKE) rocksdbjava_jar
 
 rocksdbjavastaticosx: rocksdbjavastaticosx_archs
-	mv java/target/librocksdbjni-osx-x86_64.jnilib java/target/librocksdbjni-osx.jnilib
-	mv java/target/librocksdbjni-osx-arm64.jnilib java/target/librocksdbjni-osx-aarch64.jnilib
+	cd java; $(JAR_CMD)  -cf target/$(ROCKSDB_JAR) HISTORY*.md
+	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR) librocksdbjni-osx-x86_64.jnilib librocksdbjni-osx-arm64.jnilib
+	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
+	openssl sha1 java/target/$(ROCKSDB_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR).sha1
 
 rocksdbjavastaticosx_ub: rocksdbjavastaticosx_archs
-	lipo -create -output ./java/target/$(ROCKSDBJNILIB) java/target/librocksdbjni-osx-x86_64.jnilib java/target/librocksdbjni-osx-arm64.jnilib
-	$(MAKE) rocksdbjavastatic_jar
+	cd java/target; lipo -create -output librocksdbjni-osx.jnilib librocksdbjni-osx-x86_64.jnilib librocksdbjni-osx-arm64.jnilib
+	cd java; $(JAR_CMD)  -cf target/$(ROCKSDB_JAR) HISTORY*.md
+	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR) librocksdbjni-osx.jnilib
+	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
+	openssl sha1 java/target/$(ROCKSDB_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR).sha1
 
 rocksdbjavastaticosx_archs:
 	$(MAKE) rocksdbjavastaticosx_arch_x86_64
@@ -2289,28 +2296,32 @@ rocksdbjavastatic_javalib:
 		strip $(STRIPFLAGS) $(ROCKSDBJNILIB); \
 	fi
 
-rocksdbjavastatic_jar:
+rocksdbjava_jar:
 	cd java; $(JAR_CMD)  -cf target/$(ROCKSDB_JAR) HISTORY*.md
 	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR) $(ROCKSDBJNILIB)
 	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR) org/rocksdb/*.class org/rocksdb/util/*.class
-	cd java/target/apidocs; $(JAR_CMD) -cf ../$(ROCKSDB_JAVADOCS_JAR) *
-	cd java/src/main/java; $(JAR_CMD) -cf ../../../target/$(ROCKSDB_SOURCES_JAR) org
 	openssl sha1 java/target/$(ROCKSDB_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR).sha1
+
+rocksdbjava_javadocs_jar:
+	cd java/target/apidocs; $(JAR_CMD) -cf ../$(ROCKSDB_JAVADOCS_JAR) *
 	openssl sha1 java/target/$(ROCKSDB_JAVADOCS_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAVADOCS_JAR).sha1
+
+rocksdbjava_sources_jar:
+	cd java/src/main/java; $(JAR_CMD) -cf ../../../target/$(ROCKSDB_SOURCES_JAR) org
 	openssl sha1 java/target/$(ROCKSDB_SOURCES_JAR) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_SOURCES_JAR).sha1
 
 rocksdbjavastatic_deps: $(JAVA_COMPRESSIONS)
 
 rocksdbjavastatic_libobjects: $(LIB_OBJECTS)
 
-rocksdbjavastaticrelease: rocksdbjavastaticosx
+rocksdbjavastaticrelease: rocksdbjavastaticosx rocksdbjava_javadocs_jar rocksdbjava_sources_jar
 	cd java/crossbuild && (vagrant destroy -f || true) && vagrant up linux32 && vagrant halt linux32 && vagrant up linux64 && vagrant halt linux64 && vagrant up linux64-musl && vagrant halt linux64-musl
 	cd java; $(JAR_CMD) -cf target/$(ROCKSDB_JAR_ALL) HISTORY*.md
 	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
 	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class
 	openssl sha1 java/target/$(ROCKSDB_JAR_ALL) | sed 's/.*= \([0-9a-f]*\)/\1/' > java/target/$(ROCKSDB_JAR_ALL).sha1
 
-rocksdbjavastaticreleasedocker: rocksdbjavastaticosx rocksdbjavastaticdockerx86 rocksdbjavastaticdockerx86_64 rocksdbjavastaticdockerx86musl rocksdbjavastaticdockerx86_64musl
+rocksdbjavastaticreleasedocker: rocksdbjavastaticosx rocksdbjavastaticdockerx86 rocksdbjavastaticdockerx86_64 rocksdbjavastaticdockerx86musl rocksdbjavastaticdockerx86_64musl rocksdbjava_javadocs_jar rocksdbjava_sources_jar
 	cd java; $(JAR_CMD) -cf target/$(ROCKSDB_JAR_ALL) HISTORY*.md
 	cd java/target; $(JAR_CMD) -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
 	cd java/target/classes; $(JAR_CMD) -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class

build_tools/build_detect_platform

@@ -632,7 +632,7 @@ if test "0$PORTABLE" -eq 0; then
     COMMON_FLAGS="$COMMON_FLAGS"
   elif test -n "`echo $TARGET_ARCHITECTURE | grep ^s390x`"; then
     if echo 'int main() {}' | $CXX $PLATFORM_CXXFLAGS -x c++ \
-      -fsyntax-only -march=native - -o /dev/null 2>/dev/null; then
+      -march=native - -o /dev/null 2>/dev/null; then
       COMMON_FLAGS="$COMMON_FLAGS -march=native "
     else
       COMMON_FLAGS="$COMMON_FLAGS -march=z196 "

db/arena_wrapped_db_iter.cc

@@ -58,30 +58,55 @@ Status ArenaWrappedDBIter::Refresh() {
   uint64_t cur_sv_number = cfd_->GetSuperVersionNumber();
   TEST_SYNC_POINT("ArenaWrappedDBIter::Refresh:1");
   TEST_SYNC_POINT("ArenaWrappedDBIter::Refresh:2");
-  if (sv_number_ != cur_sv_number) {
-    Env* env = db_iter_->env();
-    db_iter_->~DBIter();
-    arena_.~Arena();
-    new (&arena_) Arena();
+  while (true) {
+    if (sv_number_ != cur_sv_number) {
+      Env* env = db_iter_->env();
+      db_iter_->~DBIter();
+      arena_.~Arena();
+      new (&arena_) Arena();
 
-    SuperVersion* sv = cfd_->GetReferencedSuperVersion(db_impl_);
-    SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
-    if (read_callback_) {
-      read_callback_->Refresh(latest_seq);
+      SuperVersion* sv = cfd_->GetReferencedSuperVersion(db_impl_);
+      SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
+      if (read_callback_) {
+        read_callback_->Refresh(latest_seq);
+      }
+      Init(env, read_options_, *(cfd_->ioptions()), sv->mutable_cf_options,
+           sv->current, latest_seq,
+           sv->mutable_cf_options.max_sequential_skip_in_iterations,
+           cur_sv_number, read_callback_, db_impl_, cfd_, expose_blob_index_,
+           allow_refresh_);
+
+      InternalIterator* internal_iter = db_impl_->NewInternalIterator(
+          read_options_, cfd_, sv, &arena_, db_iter_->GetRangeDelAggregator(),
+          latest_seq, /* allow_unprepared_value */ true);
+      SetIterUnderDBIter(internal_iter);
+      break;
+    } else {
+      SequenceNumber latest_seq = db_impl_->GetLatestSequenceNumber();
+      // Refresh range-tombstones in MemTable
+      if (!read_options_.ignore_range_deletions) {
+        SuperVersion* sv = cfd_->GetThreadLocalSuperVersion(db_impl_);
+        ReadRangeDelAggregator* range_del_agg =
+            db_iter_->GetRangeDelAggregator();
+        std::unique_ptr<FragmentedRangeTombstoneIterator> range_del_iter;
+        range_del_iter.reset(
+            sv->mem->NewRangeTombstoneIterator(read_options_, latest_seq));
+        range_del_agg->AddTombstones(std::move(range_del_iter));
+        cfd_->ReturnThreadLocalSuperVersion(sv);
+      }
+      // Refresh latest sequence number
+      db_iter_->set_sequence(latest_seq);
+      db_iter_->set_valid(false);
+      // Check again if the latest super version number is changed
+      uint64_t latest_sv_number = cfd_->GetSuperVersionNumber();
+      if (latest_sv_number != cur_sv_number) {
+        // If the super version number is changed after refreshing,
+        // fallback to Re-Init the InternalIterator
+        cur_sv_number = latest_sv_number;
+        continue;
+      }
+      break;
     }
-    Init(env, read_options_, *(cfd_->ioptions()), sv->mutable_cf_options,
-         sv->current, latest_seq,
-         sv->mutable_cf_options.max_sequential_skip_in_iterations,
-         cur_sv_number, read_callback_, db_impl_, cfd_, expose_blob_index_,
-         allow_refresh_);
-
-    InternalIterator* internal_iter = db_impl_->NewInternalIterator(
-        read_options_, cfd_, sv, &arena_, db_iter_->GetRangeDelAggregator(),
-        latest_seq, /* allow_unprepared_value */ true);
-    SetIterUnderDBIter(internal_iter);
-  } else {
-    db_iter_->set_sequence(db_impl_->GetLatestSequenceNumber());
-    db_iter_->set_valid(false);
   }
   return Status::OK();
 }

db/c.cc

@@ -3757,6 +3757,9 @@ rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_bloom_format(
     const FilterPolicy* rep_;
     ~Wrapper() override { delete rep_; }
     const char* Name() const override { return rep_->Name(); }
+    const char* CompatibilityName() const override {
+      return rep_->CompatibilityName();
+    }
     // No need to override GetFilterBitsBuilder if this one is overridden
     ROCKSDB_NAMESPACE::FilterBitsBuilder* GetBuilderWithContext(
         const ROCKSDB_NAMESPACE::FilterBuildingContext& context)
@@ -3794,6 +3797,9 @@ rocksdb_filterpolicy_t* rocksdb_filterpolicy_create_ribbon_format(
     const FilterPolicy* rep_;
     ~Wrapper() override { delete rep_; }
     const char* Name() const override { return rep_->Name(); }
+    const char* CompatibilityName() const override {
+      return rep_->CompatibilityName();
+    }
     ROCKSDB_NAMESPACE::FilterBitsBuilder* GetBuilderWithContext(
         const ROCKSDB_NAMESPACE::FilterBuildingContext& context)
         const override {

db/c_test.c

@@ -7,12 +7,13 @@
 
 #ifndef ROCKSDB_LITE  // Lite does not support C API
 
-#include "rocksdb/c.h"
-
+#include <assert.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+
+#include "rocksdb/c.h"
 #ifndef OS_WIN
 #include <unistd.h>
 #endif
@@ -89,10 +90,8 @@ static void CheckEqual(const char* expected, const char* v, size_t n) {
     // ok
     return;
   } else {
-    fprintf(stderr, "%s: expected '%s', got '%s'\n",
-            phase,
-            (expected ? expected : "(null)"),
-            (v ? v : "(null"));
+    fprintf(stderr, "%s: expected '%s', got '%s'\n", phase,
+            (expected ? expected : "(null)"), (v ? v : "(null)"));
     abort();
   }
 }
@@ -989,7 +988,36 @@ int main(int argc, char** argv) {
     CheckGet(db, roptions, "foo", NULL);
     rocksdb_release_snapshot(db, snap);
   }
-
+  StartPhase("snapshot_with_memtable_inplace_update");
+  {
+    rocksdb_close(db);
+    const rocksdb_snapshot_t* snap = NULL;
+    const char* s_key = "foo_snap";
+    const char* value1 = "hello_s1";
+    const char* value2 = "hello_s2";
+    rocksdb_options_set_allow_concurrent_memtable_write(options, 0);
+    rocksdb_options_set_inplace_update_support(options, 1);
+    rocksdb_options_set_error_if_exists(options, 0);
+    db = rocksdb_open(options, dbname, &err);
+    CheckNoError(err);
+    rocksdb_put(db, woptions, s_key, 8, value1, 8, &err);
+    snap = rocksdb_create_snapshot(db);
+    assert(snap != NULL);
+    rocksdb_put(db, woptions, s_key, 8, value2, 8, &err);
+    CheckNoError(err);
+    rocksdb_readoptions_set_snapshot(roptions, snap);
+    CheckGet(db, roptions, "foo", NULL);
+    // snapshot syntax is invalid, because of inplace update supported is set
+    CheckGet(db, roptions, s_key, value2);
+    // restore the data and options
+    rocksdb_delete(db, woptions, s_key, 8, &err);
+    CheckGet(db, roptions, s_key, NULL);
+    rocksdb_release_snapshot(db, snap);
+    rocksdb_readoptions_set_snapshot(roptions, NULL);
+    rocksdb_options_set_inplace_update_support(options, 0);
+    rocksdb_options_set_allow_concurrent_memtable_write(options, 1);
+    rocksdb_options_set_error_if_exists(options, 1);
+  }
   StartPhase("repair");
   {
     // If we do not compact here, then the lazy deletion of

db/column_family.cc

@@ -1562,20 +1562,6 @@ ColumnFamilyData* ColumnFamilySet::CreateColumnFamily(
   return new_cfd;
 }
 
-// REQUIRES: DB mutex held
-void ColumnFamilySet::FreeDeadColumnFamilies() {
-  autovector<ColumnFamilyData*> to_delete;
-  for (auto cfd = dummy_cfd_->next_; cfd != dummy_cfd_; cfd = cfd->next_) {
-    if (cfd->refs_.load(std::memory_order_relaxed) == 0) {
-      to_delete.push_back(cfd);
-    }
-  }
-  for (auto cfd : to_delete) {
-    // this is very rare, so it's not a problem that we do it under a mutex
-    delete cfd;
-  }
-}
-
 // under a DB mutex AND from a write thread
 void ColumnFamilySet::RemoveColumnFamily(ColumnFamilyData* cfd) {
   auto cfd_iter = column_family_data_.find(cfd->GetID());

db/column_family.h

@@ -519,9 +519,10 @@ class ColumnFamilyData {
   ThreadLocalPtr* TEST_GetLocalSV() { return local_sv_.get(); }
   WriteBufferManager* write_buffer_mgr() { return write_buffer_manager_; }
 
+  static const uint32_t kDummyColumnFamilyDataId;
+
  private:
   friend class ColumnFamilySet;
-  static const uint32_t kDummyColumnFamilyDataId;
   ColumnFamilyData(uint32_t id, const std::string& name,
                    Version* dummy_versions, Cache* table_cache,
                    WriteBufferManager* write_buffer_manager,
@@ -627,10 +628,8 @@ class ColumnFamilyData {
 // held and it needs to be executed from the write thread. SetDropped() also
 // guarantees that it will be called only from single-threaded LogAndApply(),
 // but this condition is not that important.
-// * Iteration -- hold DB mutex, but you can release it in the body of
-// iteration. If you release DB mutex in body, reference the column
-// family before the mutex and unreference after you unlock, since the column
-// family might get dropped when the DB mutex is released
+// * Iteration -- hold DB mutex. If you want to release the DB mutex in the
+// body of the iteration, wrap in a RefedColumnFamilySet.
 // * GetDefault() -- thread safe
 // * GetColumnFamily() -- either inside of DB mutex or from a write thread
 // * GetNextColumnFamilyID(), GetMaxColumnFamily(), UpdateMaxColumnFamily(),
@@ -642,17 +641,12 @@ class ColumnFamilySet {
    public:
     explicit iterator(ColumnFamilyData* cfd)
         : current_(cfd) {}
+    // NOTE: minimum operators for for-loop iteration
     iterator& operator++() {
-      // dropped column families might still be included in this iteration
-      // (we're only removing them when client drops the last reference to the
-      // column family).
-      // dummy is never dead, so this will never be infinite
-      do {
-        current_ = current_->next_;
-      } while (current_->refs_.load(std::memory_order_relaxed) == 0);
+      current_ = current_->next_;
       return *this;
     }
-    bool operator!=(const iterator& other) {
+    bool operator!=(const iterator& other) const {
       return this->current_ != other.current_;
     }
     ColumnFamilyData* operator*() { return current_; }
@@ -691,10 +685,6 @@ class ColumnFamilySet {
   iterator begin() { return iterator(dummy_cfd_->next_); }
   iterator end() { return iterator(dummy_cfd_); }
 
-  // REQUIRES: DB mutex held
-  // Don't call while iterating over ColumnFamilySet
-  void FreeDeadColumnFamilies();
-
   Cache* get_table_cache() { return table_cache_; }
 
   WriteBufferManager* write_buffer_manager() { return write_buffer_manager_; }
@@ -737,6 +727,55 @@ class ColumnFamilySet {
   std::string db_session_id_;
 };
 
+// A wrapper for ColumnFamilySet that supports releasing DB mutex during each
+// iteration over the iterator, because the cfd is Refed and Unrefed during
+// each iteration to prevent concurrent CF drop from destroying it (until
+// Unref).
+class RefedColumnFamilySet {
+ public:
+  explicit RefedColumnFamilySet(ColumnFamilySet* cfs) : wrapped_(cfs) {}
+
+  class iterator {
+   public:
+    explicit iterator(ColumnFamilySet::iterator wrapped) : wrapped_(wrapped) {
+      MaybeRef(*wrapped_);
+    }
+    ~iterator() { MaybeUnref(*wrapped_); }
+    inline void MaybeRef(ColumnFamilyData* cfd) {
+      if (cfd->GetID() != ColumnFamilyData::kDummyColumnFamilyDataId) {
+        cfd->Ref();
+      }
+    }
+    inline void MaybeUnref(ColumnFamilyData* cfd) {
+      if (cfd->GetID() != ColumnFamilyData::kDummyColumnFamilyDataId) {
+        cfd->UnrefAndTryDelete();
+      }
+    }
+    // NOTE: minimum operators for for-loop iteration
+    inline iterator& operator++() {
+      ColumnFamilyData* old = *wrapped_;
+      ++wrapped_;
+      // Can only unref & potentially free cfd after accessing its next_
+      MaybeUnref(old);
+      MaybeRef(*wrapped_);
+      return *this;
+    }
+    inline bool operator!=(const iterator& other) const {
+      return this->wrapped_ != other.wrapped_;
+    }
+    inline ColumnFamilyData* operator*() { return *wrapped_; }
+
+   private:
+    ColumnFamilySet::iterator wrapped_;
+  };
+
+  iterator begin() { return iterator(wrapped_->begin()); }
+  iterator end() { return iterator(wrapped_->end()); }
+
+ private:
+  ColumnFamilySet* wrapped_;
+};
+
 // We use ColumnFamilyMemTablesImpl to provide WriteBatch a way to access
 // memtables of different column families (specified by ID in the write batch)
 class ColumnFamilyMemTablesImpl : public ColumnFamilyMemTables {

db/compaction/compaction_job.cc

@@ -1312,7 +1312,7 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
   }
 #endif  // !ROCKSDB_LITE
 
-  uint64_t prev_cpu_micros = db_options_.clock->CPUNanos() / 1000;
+  uint64_t prev_cpu_micros = db_options_.clock->CPUMicros();
 
   ColumnFamilyData* cfd = sub_compact->compaction->column_family_data();
 
@@ -1659,7 +1659,7 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
   }
 
   sub_compact->compaction_job_stats.cpu_micros =
-      db_options_.clock->CPUNanos() / 1000 - prev_cpu_micros;
+      db_options_.clock->CPUMicros() - prev_cpu_micros;
 
   if (measure_io_stats_) {
     sub_compact->compaction_job_stats.file_write_nanos +=

db/db_bloom_filter_test.cc

@@ -1551,9 +1551,15 @@ class LevelAndStyleCustomFilterPolicy : public FilterPolicy {
         policy_l0_other_(NewBloomFilterPolicy(bpk_l0_other)),
         policy_otherwise_(NewBloomFilterPolicy(bpk_otherwise)) {}
 
+  const char* Name() const override {
+    return "LevelAndStyleCustomFilterPolicy";
+  }
+
   // OK to use built-in policy name because we are deferring to a
   // built-in builder. We aren't changing the serialized format.
-  const char* Name() const override { return policy_fifo_->Name(); }
+  const char* CompatibilityName() const override {
+    return policy_fifo_->CompatibilityName();
+  }
 
   FilterBitsBuilder* GetBuilderWithContext(
       const FilterBuildingContext& context) const override {

db/db_compaction_test.cc

@@ -6889,6 +6889,145 @@ TEST_F(DBCompactionTest, FIFOWarm) {
   Destroy(options);
 }
 
+TEST_F(DBCompactionTest, DisableMultiManualCompaction) {
+  const int kNumL0Files = 10;
+
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = kNumL0Files;
+  Reopen(options);
+
+  // Generate 2 levels of file to make sure the manual compaction is not skipped
+  for (int i = 0; i < 10; i++) {
+    ASSERT_OK(Put(Key(i), "value"));
+    if (i % 2) {
+      ASSERT_OK(Flush());
+    }
+  }
+  MoveFilesToLevel(2);
+
+  for (int i = 0; i < 10; i++) {
+    ASSERT_OK(Put(Key(i), "value"));
+    if (i % 2) {
+      ASSERT_OK(Flush());
+    }
+  }
+  MoveFilesToLevel(1);
+
+  // Block compaction queue
+  test::SleepingBackgroundTask sleeping_task_low;
+  env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask, &sleeping_task_low,
+                 Env::Priority::LOW);
+
+  port::Thread compact_thread1([&]() {
+    CompactRangeOptions cro;
+    cro.exclusive_manual_compaction = false;
+    std::string begin_str = Key(0);
+    std::string end_str = Key(3);
+    Slice b = begin_str;
+    Slice e = end_str;
+    auto s = db_->CompactRange(cro, &b, &e);
+    ASSERT_TRUE(s.IsIncomplete());
+  });
+
+  port::Thread compact_thread2([&]() {
+    CompactRangeOptions cro;
+    cro.exclusive_manual_compaction = false;
+    std::string begin_str = Key(4);
+    std::string end_str = Key(7);
+    Slice b = begin_str;
+    Slice e = end_str;
+    auto s = db_->CompactRange(cro, &b, &e);
+    ASSERT_TRUE(s.IsIncomplete());
+  });
+
+  // Disable manual compaction should cancel both manual compactions and both
+  // compaction should return incomplete.
+  db_->DisableManualCompaction();
+
+  compact_thread1.join();
+  compact_thread2.join();
+
+  sleeping_task_low.WakeUp();
+  sleeping_task_low.WaitUntilDone();
+  ASSERT_OK(dbfull()->TEST_WaitForCompact(true));
+}
+
+TEST_F(DBCompactionTest, DisableJustStartedManualCompaction) {
+  const int kNumL0Files = 4;
+
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = kNumL0Files;
+  Reopen(options);
+
+  // generate files, but avoid trigger auto compaction
+  for (int i = 0; i < kNumL0Files / 2; i++) {
+    ASSERT_OK(Put(Key(1), "value1"));
+    ASSERT_OK(Put(Key(2), "value2"));
+    ASSERT_OK(Flush());
+  }
+
+  // make sure the manual compaction background is started but not yet set the
+  // status to in_progress, then cancel the manual compaction, which should not
+  // result in segfault
+  SyncPoint::GetInstance()->LoadDependency(
+      {{"DBImpl::BGWorkCompaction",
+        "DBCompactionTest::DisableJustStartedManualCompaction:"
+        "PreDisableManualCompaction"},
+       {"DBImpl::RunManualCompaction:Unscheduled",
+        "BackgroundCallCompaction:0"}});
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  port::Thread compact_thread([&]() {
+    CompactRangeOptions cro;
+    cro.exclusive_manual_compaction = true;
+    auto s = db_->CompactRange(cro, nullptr, nullptr);
+    ASSERT_TRUE(s.IsIncomplete());
+  });
+  TEST_SYNC_POINT(
+      "DBCompactionTest::DisableJustStartedManualCompaction:"
+      "PreDisableManualCompaction");
+  db_->DisableManualCompaction();
+
+  compact_thread.join();
+}
+
+TEST_F(DBCompactionTest, DisableInProgressManualCompaction) {
+  const int kNumL0Files = 4;
+
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = kNumL0Files;
+  Reopen(options);
+
+  SyncPoint::GetInstance()->LoadDependency(
+      {{"DBImpl::BackgroundCompaction:InProgress",
+        "DBCompactionTest::DisableInProgressManualCompaction:"
+        "PreDisableManualCompaction"},
+       {"DBImpl::RunManualCompaction:Unscheduled",
+        "CompactionJob::Run():Start"}});
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  // generate files, but avoid trigger auto compaction
+  for (int i = 0; i < kNumL0Files / 2; i++) {
+    ASSERT_OK(Put(Key(1), "value1"));
+    ASSERT_OK(Put(Key(2), "value2"));
+    ASSERT_OK(Flush());
+  }
+
+  port::Thread compact_thread([&]() {
+    CompactRangeOptions cro;
+    cro.exclusive_manual_compaction = true;
+    auto s = db_->CompactRange(cro, nullptr, nullptr);
+    ASSERT_TRUE(s.IsIncomplete());
+  });
+
+  TEST_SYNC_POINT(
+      "DBCompactionTest::DisableInProgressManualCompaction:"
+      "PreDisableManualCompaction");
+  db_->DisableManualCompaction();
+
+  compact_thread.join();
+}
+
 TEST_F(DBCompactionTest, DisableManualCompactionThreadQueueFull) {
   const int kNumL0Files = 4;
 
@@ -6951,7 +7090,7 @@ TEST_F(DBCompactionTest, DisableManualCompactionThreadQueueFullDBClose) {
 
   SyncPoint::GetInstance()->LoadDependency(
       {{"DBImpl::RunManualCompaction:Scheduled",
-        "DBCompactionTest::DisableManualCompactionThreadQueueFull:"
+        "DBCompactionTest::DisableManualCompactionThreadQueueFullDBClose:"
         "PreDisableManualCompaction"}});
   SyncPoint::GetInstance()->EnableProcessing();
 
@@ -6979,7 +7118,7 @@ TEST_F(DBCompactionTest, DisableManualCompactionThreadQueueFullDBClose) {
   });
 
   TEST_SYNC_POINT(
-      "DBCompactionTest::DisableManualCompactionThreadQueueFull:"
+      "DBCompactionTest::DisableManualCompactionThreadQueueFullDBClose:"
       "PreDisableManualCompaction");
 
   // Generate more files to trigger auto compaction which is scheduled after
@@ -7006,6 +7145,63 @@ TEST_F(DBCompactionTest, DisableManualCompactionThreadQueueFullDBClose) {
   sleeping_task_low.WaitUntilDone();
 }
 
+TEST_F(DBCompactionTest, DBCloseWithManualCompaction) {
+  const int kNumL0Files = 4;
+
+  SyncPoint::GetInstance()->LoadDependency(
+      {{"DBImpl::RunManualCompaction:Scheduled",
+        "DBCompactionTest::DisableManualCompactionThreadQueueFullDBClose:"
+        "PreDisableManualCompaction"}});
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = kNumL0Files;
+  Reopen(options);
+
+  // Block compaction queue
+  test::SleepingBackgroundTask sleeping_task_low;
+  env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask, &sleeping_task_low,
+                 Env::Priority::LOW);
+
+  // generate files, but avoid trigger auto compaction
+  for (int i = 0; i < kNumL0Files / 2; i++) {
+    ASSERT_OK(Put(Key(1), "value1"));
+    ASSERT_OK(Put(Key(2), "value2"));
+    ASSERT_OK(Flush());
+  }
+
+  port::Thread compact_thread([&]() {
+    CompactRangeOptions cro;
+    cro.exclusive_manual_compaction = true;
+    auto s = db_->CompactRange(cro, nullptr, nullptr);
+    ASSERT_TRUE(s.IsIncomplete());
+  });
+
+  TEST_SYNC_POINT(
+      "DBCompactionTest::DisableManualCompactionThreadQueueFullDBClose:"
+      "PreDisableManualCompaction");
+
+  // Generate more files to trigger auto compaction which is scheduled after
+  // manual compaction. Has to generate 4 more files because existing files are
+  // pending compaction
+  for (int i = 0; i < kNumL0Files; i++) {
+    ASSERT_OK(Put(Key(1), "value1"));
+    ASSERT_OK(Put(Key(2), "value2"));
+    ASSERT_OK(Flush());
+  }
+  ASSERT_EQ(ToString(kNumL0Files + (kNumL0Files / 2)), FilesPerLevel(0));
+
+  // Close DB with manual compaction and auto triggered compaction in the queue.
+  auto s = db_->Close();
+  ASSERT_OK(s);
+
+  // manual compaction thread should return with Incomplete().
+  compact_thread.join();
+
+  sleeping_task_low.WakeUp();
+  sleeping_task_low.WaitUntilDone();
+}
+
 TEST_F(DBCompactionTest,
        DisableManualCompactionDoesNotWaitForDrainingAutomaticCompaction) {
   // When `CompactRangeOptions::exclusive_manual_compaction == true`, we wait

db/db_filesnapshot.cc

@@ -45,17 +45,15 @@ Status DBImpl::FlushForGetLiveFiles() {
     }
     mutex_.Lock();
   } else {
-    for (auto cfd : *versions_->GetColumnFamilySet()) {
+    for (auto cfd : versions_->GetRefedColumnFamilySet()) {
       if (cfd->IsDropped()) {
         continue;
       }
-      cfd->Ref();
       mutex_.Unlock();
       status = FlushMemTable(cfd, FlushOptions(), FlushReason::kGetLiveFiles);
       TEST_SYNC_POINT("DBImpl::GetLiveFiles:1");
       TEST_SYNC_POINT("DBImpl::GetLiveFiles:2");
       mutex_.Lock();
-      cfd->UnrefAndTryDelete();
       if (!status.ok() && !status.IsColumnFamilyDropped()) {
         break;
       } else if (status.IsColumnFamilyDropped()) {
@@ -63,7 +61,6 @@ Status DBImpl::FlushForGetLiveFiles() {
       }
     }
   }
-  versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
   return status;
 }
 

db/db_flush_test.cc

@@ -676,6 +676,7 @@ class TestFlushListener : public EventListener {
   ~TestFlushListener() override {
     prev_fc_info_.status.PermitUncheckedError();  // Ignore the status
   }
+
   void OnTableFileCreated(const TableFileCreationInfo& info) override {
     // remember the info for later checking the FlushJobInfo.
     prev_fc_info_ = info;
@@ -1999,6 +2000,61 @@ TEST_P(DBFlushTestBlobError, FlushError) {
 }
 
 #ifndef ROCKSDB_LITE
+TEST_F(DBFlushTest, TombstoneVisibleInSnapshot) {
+  class SimpleTestFlushListener : public EventListener {
+   public:
+    explicit SimpleTestFlushListener(DBFlushTest* _test) : test_(_test) {}
+    ~SimpleTestFlushListener() override {}
+
+    void OnFlushBegin(DB* db, const FlushJobInfo& info) override {
+      ASSERT_EQ(static_cast<uint32_t>(0), info.cf_id);
+
+      ASSERT_OK(db->Delete(WriteOptions(), "foo"));
+      snapshot_ = db->GetSnapshot();
+      ASSERT_OK(db->Put(WriteOptions(), "foo", "value"));
+
+      auto* dbimpl = static_cast_with_check<DBImpl>(db);
+      assert(dbimpl);
+
+      ColumnFamilyHandle* cfh = db->DefaultColumnFamily();
+      auto* cfhi = static_cast_with_check<ColumnFamilyHandleImpl>(cfh);
+      assert(cfhi);
+      ASSERT_OK(dbimpl->TEST_SwitchMemtable(cfhi->cfd()));
+    }
+
+    DBFlushTest* test_ = nullptr;
+    const Snapshot* snapshot_ = nullptr;
+  };
+
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  auto* listener = new SimpleTestFlushListener(this);
+  options.listeners.emplace_back(listener);
+  DestroyAndReopen(options);
+
+  ASSERT_OK(db_->Put(WriteOptions(), "foo", "value0"));
+
+  ManagedSnapshot snapshot_guard(db_);
+
+  ColumnFamilyHandle* default_cf = db_->DefaultColumnFamily();
+  ASSERT_OK(db_->Flush(FlushOptions(), default_cf));
+
+  const Snapshot* snapshot = listener->snapshot_;
+  assert(snapshot);
+
+  ReadOptions read_opts;
+  read_opts.snapshot = snapshot;
+
+  // Using snapshot should not see "foo".
+  {
+    std::string value;
+    Status s = db_->Get(read_opts, "foo", &value);
+    ASSERT_TRUE(s.IsNotFound());
+  }
+
+  db_->ReleaseSnapshot(snapshot);
+}
+
 TEST_P(DBAtomicFlushTest, ManualFlushUnder2PC) {
   Options options = CurrentOptions();
   options.create_if_missing = true;

db/db_impl/compacted_db_impl.cc

@@ -171,7 +171,9 @@ Status CompactedDBImpl::Open(const Options& options,
   std::unique_ptr<CompactedDBImpl> db(new CompactedDBImpl(db_options, dbname));
   Status s = db->Init(options);
   if (s.ok()) {
-    db->StartPeriodicWorkScheduler();
+    s = db->StartPeriodicWorkScheduler();
+  }
+  if (s.ok()) {
     ROCKS_LOG_INFO(db->immutable_db_options_.info_log,
                    "Opened the db as fully compacted mode");
     LogFlush(db->immutable_db_options_.info_log);

db/db_impl/db_impl.cc

@@ -377,15 +377,12 @@ Status DBImpl::ResumeImpl(DBRecoverContext context) {
       s = AtomicFlushMemTables(cfds, flush_opts, context.flush_reason);
       mutex_.Lock();
     } else {
-      for (auto cfd : *versions_->GetColumnFamilySet()) {
+      for (auto cfd : versions_->GetRefedColumnFamilySet()) {
         if (cfd->IsDropped()) {
           continue;
         }
-        cfd->Ref();
-        mutex_.Unlock();
+        InstrumentedMutexUnlock u(&mutex_);
         s = FlushMemTable(cfd, flush_opts, context.flush_reason);
-        mutex_.Lock();
-        cfd->UnrefAndTryDelete();
         if (!s.ok()) {
           break;
         }
@@ -400,14 +397,6 @@ Status DBImpl::ResumeImpl(DBRecoverContext context) {
 
   JobContext job_context(0);
   FindObsoleteFiles(&job_context, true);
-  if (s.ok()) {
-    s = error_handler_.ClearBGError();
-  } else {
-    // NOTE: this is needed to pass ASSERT_STATUS_CHECKED
-    // in the DBSSTTest.DBWithMaxSpaceAllowedRandomized test.
-    // See https://github.com/facebook/rocksdb/pull/7715#issuecomment-754947952
-    error_handler_.GetRecoveryError().PermitUncheckedError();
-  }
   mutex_.Unlock();
 
   job_context.manifest_file_number = 1;
@@ -428,11 +417,31 @@ Status DBImpl::ResumeImpl(DBRecoverContext context) {
             immutable_db_options_.info_log,
             "DB resume requested but could not enable file deletions [%s]",
             s.ToString().c_str());
+        assert(false);
       }
     }
-    ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");
   }
+
   mutex_.Lock();
+  if (s.ok()) {
+    // This will notify and unblock threads waiting for error recovery to
+    // finish. Those previouly waiting threads can now proceed, which may
+    // include closing the db.
+    s = error_handler_.ClearBGError();
+  } else {
+    // NOTE: this is needed to pass ASSERT_STATUS_CHECKED
+    // in the DBSSTTest.DBWithMaxSpaceAllowedRandomized test.
+    // See https://github.com/facebook/rocksdb/pull/7715#issuecomment-754947952
+    error_handler_.GetRecoveryError().PermitUncheckedError();
+  }
+
+  if (s.ok()) {
+    ROCKS_LOG_INFO(immutable_db_options_.info_log, "Successfully resumed DB");
+  } else {
+    ROCKS_LOG_INFO(immutable_db_options_.info_log, "Failed to resume DB [%s]",
+                   s.ToString().c_str());
+  }
+
   // Check for shutdown again before scheduling further compactions,
   // since we released and re-acquired the lock above
   if (shutdown_initiated_) {
@@ -485,18 +494,14 @@ void DBImpl::CancelAllBackgroundWork(bool wait) {
       s.PermitUncheckedError();  //**TODO: What to do on error?
       mutex_.Lock();
     } else {
-      for (auto cfd : *versions_->GetColumnFamilySet()) {
+      for (auto cfd : versions_->GetRefedColumnFamilySet()) {
         if (!cfd->IsDropped() && cfd->initialized() && !cfd->mem()->IsEmpty()) {
-          cfd->Ref();
-          mutex_.Unlock();
+          InstrumentedMutexUnlock u(&mutex_);
           Status s = FlushMemTable(cfd, FlushOptions(), FlushReason::kShutDown);
           s.PermitUncheckedError();  //**TODO: What to do on error?
-          mutex_.Lock();
-          cfd->UnrefAndTryDelete();
         }
       }
     }
-    versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
   }
 
   shutting_down_.store(true, std::memory_order_release);
@@ -527,10 +532,19 @@ Status DBImpl::CloseHelper() {
   // marker. After this we do a variant of the waiting and unschedule work
   // (to consider: moving all the waiting into CancelAllBackgroundWork(true))
   CancelAllBackgroundWork(false);
+
+  // Cancel manual compaction if there's any
+  if (HasPendingManualCompaction()) {
+    DisableManualCompaction();
+  }
   mutex_.Lock();
-  env_->UnSchedule(this, Env::Priority::BOTTOM);
-  env_->UnSchedule(this, Env::Priority::LOW);
-  env_->UnSchedule(this, Env::Priority::HIGH);
+  // Unschedule all tasks for this DB
+  for (uint8_t i = 0; i < static_cast<uint8_t>(TaskType::kCount); i++) {
+    env_->UnSchedule(GetTaskTag(i), Env::Priority::BOTTOM);
+    env_->UnSchedule(GetTaskTag(i), Env::Priority::LOW);
+    env_->UnSchedule(GetTaskTag(i), Env::Priority::HIGH);
+  }
+
   Status ret = Status::OK();
 
   // Wait for background work to finish
@@ -749,7 +763,7 @@ void DBImpl::PrintStatistics() {
   }
 }
 
-void DBImpl::StartPeriodicWorkScheduler() {
+Status DBImpl::StartPeriodicWorkScheduler() {
 #ifndef ROCKSDB_LITE
 
 #ifndef NDEBUG
@@ -759,7 +773,7 @@ void DBImpl::StartPeriodicWorkScheduler() {
       "DBImpl::StartPeriodicWorkScheduler:DisableScheduler",
       &disable_scheduler);
   if (disable_scheduler) {
-    return;
+    return Status::OK();
   }
 #endif  // !NDEBUG
 
@@ -770,10 +784,11 @@ void DBImpl::StartPeriodicWorkScheduler() {
                              &periodic_work_scheduler_);
   }
 
-  periodic_work_scheduler_->Register(
+  return periodic_work_scheduler_->Register(
       this, mutable_db_options_.stats_dump_period_sec,
       mutable_db_options_.stats_persist_period_sec);
 #endif  // !ROCKSDB_LITE
+  return Status::OK();
 }
 
 // esitmate the total size of stats_history_
@@ -949,18 +964,13 @@ void DBImpl::DumpStats() {
   TEST_SYNC_POINT("DBImpl::DumpStats:StartRunning");
   {
     InstrumentedMutexLock l(&mutex_);
-    for (auto cfd : *versions_->GetColumnFamilySet()) {
+    for (auto cfd : versions_->GetRefedColumnFamilySet()) {
       if (cfd->initialized()) {
         // Release DB mutex for gathering cache entry stats. Pass over all
         // column families for this first so that other stats are dumped
         // near-atomically.
-        // Get a ref before unlocking
-        cfd->Ref();
-        {
-          InstrumentedMutexUnlock u(&mutex_);
-          cfd->internal_stats()->CollectCacheEntryStats(/*foreground=*/false);
-        }
-        cfd->UnrefAndTryDelete();
+        InstrumentedMutexUnlock u(&mutex_);
+        cfd->internal_stats()->CollectCacheEntryStats(/*foreground=*/false);
       }
     }
 
@@ -1207,7 +1217,7 @@ Status DBImpl::SetDBOptions(
               mutable_db_options_.stats_persist_period_sec) {
         mutex_.Unlock();
         periodic_work_scheduler_->Unregister(this);
-        periodic_work_scheduler_->Register(
+        s = periodic_work_scheduler_->Register(
             this, new_options.stats_dump_period_sec,
             new_options.stats_persist_period_sec);
         mutex_.Lock();
@@ -3185,6 +3195,12 @@ bool CfdListContains(const CfdList& list, ColumnFamilyData* cfd) {
 }  //  namespace
 
 void DBImpl::ReleaseSnapshot(const Snapshot* s) {
+  if (s == nullptr) {
+    // DBImpl::GetSnapshot() can return nullptr when snapshot
+    // not supported by specifying the condition:
+    // inplace_update_support enabled.
+    return;
+  }
   const SnapshotImpl* casted_s = reinterpret_cast<const SnapshotImpl*>(s);
   {
     InstrumentedMutexLock l(&mutex_);
@@ -3464,15 +3480,13 @@ bool DBImpl::GetAggregatedIntProperty(const Slice& property,
     // Needs mutex to protect the list of column families.
     InstrumentedMutexLock l(&mutex_);
     uint64_t value;
-    for (auto* cfd : *versions_->GetColumnFamilySet()) {
+    for (auto* cfd : versions_->GetRefedColumnFamilySet()) {
       if (!cfd->initialized()) {
         continue;
       }
-      cfd->Ref();
       ret = GetIntPropertyInternal(cfd, *property_info, true, &value);
       // GetIntPropertyInternal may release db mutex and re-acquire it.
       mutex_.AssertHeld();
-      cfd->UnrefAndTryDelete();
       if (ret) {
         sum += value;
       } else {
@@ -5063,6 +5077,7 @@ Status DBImpl::VerifyChecksumInternal(const ReadOptions& read_options,
     }
   }
 
+  // TODO: simplify using GetRefedColumnFamilySet?
   std::vector<ColumnFamilyData*> cfd_list;
   {
     InstrumentedMutexLock l(&mutex_);

db/db_impl/db_impl.h

@@ -1187,7 +1187,10 @@ class DBImpl : public DB {
   // WriteToWAL need different synchronization: log_empty_, alive_log_files_,
   // logs_, logfile_number_. Refer to the definition of each variable below for
   // more description.
-  mutable InstrumentedMutex mutex_;
+  //
+  // `mutex_` can be a hot lock in some workloads, so it deserves dedicated
+  // cachelines.
+  mutable CacheAlignedInstrumentedMutex mutex_;
 
   ColumnFamilyHandleImpl* default_cf_handle_;
   InternalStats* default_cf_internal_stats_;
@@ -1511,19 +1514,31 @@ class DBImpl : public DB {
 
   // Information for a manual compaction
   struct ManualCompactionState {
+    ManualCompactionState(ColumnFamilyData* _cfd, int _input_level,
+                          int _output_level, uint32_t _output_path_id,
+                          bool _exclusive, bool _disallow_trivial_move,
+                          std::atomic<bool>* _canceled)
+        : cfd(_cfd),
+          input_level(_input_level),
+          output_level(_output_level),
+          output_path_id(_output_path_id),
+          exclusive(_exclusive),
+          disallow_trivial_move(_disallow_trivial_move),
+          canceled(_canceled) {}
+
     ColumnFamilyData* cfd;
     int input_level;
     int output_level;
     uint32_t output_path_id;
     Status status;
-    bool done;
-    bool in_progress;             // compaction request being processed?
-    bool incomplete;              // only part of requested range compacted
-    bool exclusive;               // current behavior of only one manual
-    bool disallow_trivial_move;   // Force actual compaction to run
-    const InternalKey* begin;     // nullptr means beginning of key range
-    const InternalKey* end;       // nullptr means end of key range
-    InternalKey* manual_end;      // how far we are compacting
+    bool done = false;
+    bool in_progress = false;    // compaction request being processed?
+    bool incomplete = false;     // only part of requested range compacted
+    bool exclusive;              // current behavior of only one manual
+    bool disallow_trivial_move;  // Force actual compaction to run
+    const InternalKey* begin = nullptr;  // nullptr means beginning of key range
+    const InternalKey* end = nullptr;    // nullptr means end of key range
+    InternalKey* manual_end = nullptr;   // how far we are compacting
     InternalKey tmp_storage;      // Used to keep track of compaction progress
     InternalKey tmp_storage1;     // Used to keep track of compaction progress
     std::atomic<bool>* canceled;  // Compaction canceled by the user?
@@ -1536,7 +1551,6 @@ class DBImpl : public DB {
     ManualCompactionState* manual_compaction_state;  // nullptr if non-manual
     // task limiter token is requested during compaction picking.
     std::unique_ptr<TaskLimiterToken> task_token;
-    bool is_canceled = false;
   };
 
   struct CompactionArg {
@@ -1731,6 +1745,25 @@ class DBImpl : public DB {
     }
   }
 
+  // TaskType is used to identify tasks in thread-pool, currently only
+  // differentiate manual compaction, which could be unscheduled from the
+  // thread-pool.
+  enum class TaskType : uint8_t {
+    kDefault = 0,
+    kManualCompaction = 1,
+    kCount = 2,
+  };
+
+  // Task tag is used to identity tasks in thread-pool, which is
+  // dbImpl obj address + type
+  inline void* GetTaskTag(TaskType type) {
+    return GetTaskTag(static_cast<uint8_t>(type));
+  }
+
+  inline void* GetTaskTag(uint8_t type) {
+    return static_cast<uint8_t*>(static_cast<void*>(this)) + type;
+  }
+
   // REQUIRES: mutex locked and in write thread.
   void AssignAtomicFlushSeq(const autovector<ColumnFamilyData*>& cfds);
 
@@ -1749,7 +1782,8 @@ class DBImpl : public DB {
                          WriteBatch** to_be_cached_state);
 
   IOStatus WriteToWAL(const WriteBatch& merged_batch, log::Writer* log_writer,
-                      uint64_t* log_used, uint64_t* log_size);
+                      uint64_t* log_used, uint64_t* log_size,
+                      bool with_db_mutex = false, bool with_log_mutex = false);
 
   IOStatus WriteToWAL(const WriteThread::WriteGroup& write_group,
                       log::Writer* log_writer, uint64_t* log_used,
@@ -1845,7 +1879,7 @@ class DBImpl : public DB {
                               LogBuffer* log_buffer);
 
   // Schedule background tasks
-  void StartPeriodicWorkScheduler();
+  Status StartPeriodicWorkScheduler();
 
   void PrintStatistics();
 
@@ -2075,12 +2109,15 @@ class DBImpl : public DB {
   bool persistent_stats_cfd_exists_ = true;
 
   // Without two_write_queues, read and writes to alive_log_files_ are
-  // protected by mutex_. However since back() is never popped, and push_back()
-  // is done only from write_thread_, the same thread can access the item
-  // reffered by back() without mutex_. With two_write_queues_, writes
+  // protected by mutex_. With two_write_queues_, writes
   // are protected by locking both mutex_ and log_write_mutex_, and reads must
   // be under either mutex_ or log_write_mutex_.
   std::deque<LogFileNumberSize> alive_log_files_;
+  // Caching the result of `alive_log_files_.back()` so that we do not have to
+  // call `alive_log_files_.back()` in the write thread (WriteToWAL()) which
+  // requires locking db mutex if log_mutex_ is not already held in
+  // two-write-queues mode.
+  std::deque<LogFileNumberSize>::reverse_iterator alive_log_files_tail_;
   // Log files that aren't fully synced, and the current log file.
   // Synchronization:
   //  - push_back() is done from write_thread_ with locked mutex_ and

db/db_impl/db_impl_compaction_flush.cc

@@ -170,6 +170,7 @@ Status DBImpl::FlushMemTableToOutputFile(
   const bool needs_to_sync_closed_wals =
       logfile_number_ > 0 &&
       versions_->GetColumnFamilySet()->NumberOfColumnFamilies() > 1;
+
   // If needs_to_sync_closed_wals is true, we need to record the current
   // maximum memtable ID of this column family so that a later PickMemtables()
   // call will not pick memtables whose IDs are higher. This is due to the fact
@@ -177,9 +178,33 @@ Status DBImpl::FlushMemTableToOutputFile(
   // happen for this column family in the meantime. The newly created memtables
   // have their data backed by unsynced WALs, thus they cannot be included in
   // this flush job.
+  // Another reason why we must record the current maximum memtable ID of this
+  // column family: SyncClosedLogs() may release db mutex, thus it's possible
+  // for application to continue to insert into memtables increasing db's
+  // sequence number. The application may take a snapshot, but this snapshot is
+  // not included in `snapshot_seqs` which will be passed to flush job because
+  // `snapshot_seqs` has already been computed before this function starts.
+  // Recording the max memtable ID ensures that the flush job does not flush
+  // a memtable without knowing such snapshot(s).
   uint64_t max_memtable_id = needs_to_sync_closed_wals
                                  ? cfd->imm()->GetLatestMemTableID()
                                  : port::kMaxUint64;
+
+  // If needs_to_sync_closed_wals is false, then the flush job will pick ALL
+  // existing memtables of the column family when PickMemTable() is called
+  // later. Although we won't call SyncClosedLogs() in this case, we may still
+  // call the callbacks of the listeners, i.e. NotifyOnFlushBegin() which also
+  // releases and re-acquires the db mutex. In the meantime, the application
+  // can still insert into the memtables and increase the db's sequence number.
+  // The application can take a snapshot, hoping that the latest visible state
+  // to this snapshto is preserved. This is hard to guarantee since db mutex
+  // not held. This newly-created snapshot is not included in `snapshot_seqs`
+  // and the flush job is unaware of its presence. Consequently, the flush job
+  // may drop certain keys when generating the L0, causing incorrect data to be
+  // returned for snapshot read using this snapshot.
+  // To address this, we make sure NotifyOnFlushBegin() executes after memtable
+  // picking so that no new snapshot can be taken between the two functions.
+
   FlushJob flush_job(
       dbname_, cfd, immutable_db_options_, mutable_cf_options, max_memtable_id,
       file_options_for_compaction_, versions_.get(), &mutex_, &shutting_down_,
@@ -192,11 +217,6 @@ Status DBImpl::FlushMemTableToOutputFile(
       &blob_callback_);
   FileMetaData file_meta;
 
-#ifndef ROCKSDB_LITE
-  // may temporarily unlock and lock the mutex.
-  NotifyOnFlushBegin(cfd, &file_meta, mutable_cf_options, job_context->job_id);
-#endif  // ROCKSDB_LITE
-
   Status s;
   bool need_cancel = false;
   IOStatus log_io_s = IOStatus::OK();
@@ -221,6 +241,12 @@ Status DBImpl::FlushMemTableToOutputFile(
   }
   TEST_SYNC_POINT_CALLBACK(
       "DBImpl::FlushMemTableToOutputFile:AfterPickMemtables", &flush_job);
+
+#ifndef ROCKSDB_LITE
+  // may temporarily unlock and lock the mutex.
+  NotifyOnFlushBegin(cfd, &file_meta, mutable_cf_options, job_context->job_id);
+#endif  // ROCKSDB_LITE
+
   bool switched_to_mempurge = false;
   // Within flush_job.Run, rocksdb may call event listener to notify
   // file creation and deletion.
@@ -1763,18 +1789,13 @@ Status DBImpl::RunManualCompaction(
   CompactionArg* ca = nullptr;
 
   bool scheduled = false;
+  bool unscheduled = false;
+  Env::Priority thread_pool_priority = Env::Priority::TOTAL;
   bool manual_conflict = false;
-  ManualCompactionState manual;
-  manual.cfd = cfd;
-  manual.input_level = input_level;
-  manual.output_level = output_level;
-  manual.output_path_id = compact_range_options.target_path_id;
-  manual.done = false;
-  manual.in_progress = false;
-  manual.incomplete = false;
-  manual.exclusive = exclusive;
-  manual.disallow_trivial_move = disallow_trivial_move;
-  manual.canceled = compact_range_options.canceled;
+
+  ManualCompactionState manual(
+      cfd, input_level, output_level, compact_range_options.target_path_id,
+      exclusive, disallow_trivial_move, compact_range_options.canceled);
   // For universal compaction, we enforce every manual compaction to compact
   // all files.
   if (begin == nullptr ||
@@ -1879,15 +1900,22 @@ Status DBImpl::RunManualCompaction(
       assert(!exclusive || !manual_conflict);
       // Running either this or some other manual compaction
       bg_cv_.Wait();
-      if (manual_compaction_paused_ > 0 && !manual.done &&
-          !manual.in_progress) {
-        manual.done = true;
-        manual.status =
-            Status::Incomplete(Status::SubCode::kManualCompactionPaused);
-        if (ca && ca->prepicked_compaction) {
-          ca->prepicked_compaction->is_canceled = true;
+      if (manual_compaction_paused_ > 0 && scheduled && !unscheduled) {
+        assert(thread_pool_priority != Env::Priority::TOTAL);
+        // unschedule all manual compactions
+        auto unscheduled_task_num = env_->UnSchedule(
+            GetTaskTag(TaskType::kManualCompaction), thread_pool_priority);
+        if (unscheduled_task_num > 0) {
+          ROCKS_LOG_INFO(
+              immutable_db_options_.info_log,
+              "[%s] Unscheduled %d number of manual compactions from the "
+              "thread-pool",
+              cfd->GetName().c_str(), unscheduled_task_num);
+          // it may unschedule other manual compactions, notify others.
+          bg_cv_.SignalAll();
         }
-        break;
+        unscheduled = true;
+        TEST_SYNC_POINT("DBImpl::RunManualCompaction:Unscheduled");
       }
       if (scheduled && manual.incomplete == true) {
         assert(!manual.in_progress);
@@ -1916,13 +1944,17 @@ Status DBImpl::RunManualCompaction(
         bg_bottom_compaction_scheduled_++;
         ca->compaction_pri_ = Env::Priority::BOTTOM;
         env_->Schedule(&DBImpl::BGWorkBottomCompaction, ca,
-                       Env::Priority::BOTTOM, this,
+                       Env::Priority::BOTTOM,
+                       GetTaskTag(TaskType::kManualCompaction),
                        &DBImpl::UnscheduleCompactionCallback);
+        thread_pool_priority = Env::Priority::BOTTOM;
       } else {
         bg_compaction_scheduled_++;
         ca->compaction_pri_ = Env::Priority::LOW;
-        env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, this,
+        env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW,
+                       GetTaskTag(TaskType::kManualCompaction),
                        &DBImpl::UnscheduleCompactionCallback);
+        thread_pool_priority = Env::Priority::LOW;
       }
       scheduled = true;
       TEST_SYNC_POINT("DBImpl::RunManualCompaction:Scheduled");
@@ -1933,6 +1965,13 @@ Status DBImpl::RunManualCompaction(
   assert(!manual.in_progress);
   assert(HasPendingManualCompaction());
   RemoveManualCompaction(&manual);
+  // if the manual job is unscheduled, try schedule other jobs in case there's
+  // any unscheduled compaction job which was blocked by exclusive manual
+  // compaction.
+  if (manual.status.IsIncomplete() &&
+      manual.status.subcode() == Status::SubCode::kManualCompactionPaused) {
+    MaybeScheduleFlushOrCompaction();
+  }
   bg_cv_.SignalAll();
   return manual.status;
 }
@@ -2660,7 +2699,15 @@ void DBImpl::UnscheduleCompactionCallback(void* arg) {
   CompactionArg ca = *(ca_ptr);
   delete reinterpret_cast<CompactionArg*>(arg);
   if (ca.prepicked_compaction != nullptr) {
+    // if it's a manual compaction, set status to ManualCompactionPaused
+    if (ca.prepicked_compaction->manual_compaction_state) {
+      ca.prepicked_compaction->manual_compaction_state->done = true;
+      ca.prepicked_compaction->manual_compaction_state->status =
+          Status::Incomplete(Status::SubCode::kManualCompactionPaused);
+    }
     if (ca.prepicked_compaction->compaction != nullptr) {
+      ca.prepicked_compaction->compaction->ReleaseCompactionFiles(
+          Status::Incomplete(Status::SubCode::kManualCompactionPaused));
       delete ca.prepicked_compaction->compaction;
     }
     delete ca.prepicked_compaction;
@@ -2851,106 +2898,93 @@ void DBImpl::BackgroundCallFlush(Env::Priority thread_pri) {
 void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
                                       Env::Priority bg_thread_pri) {
   bool made_progress = false;
+  JobContext job_context(next_job_id_.fetch_add(1), true);
   TEST_SYNC_POINT("BackgroundCallCompaction:0");
   LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL,
                        immutable_db_options_.info_log.get());
   {
     InstrumentedMutexLock l(&mutex_);
 
-    if (prepicked_compaction && prepicked_compaction->is_canceled) {
-      assert(prepicked_compaction->compaction);
-      ROCKS_LOG_BUFFER(&log_buffer, "[%s] Skip canceled manual compaction job",
-                       prepicked_compaction->compaction->column_family_data()
-                           ->GetName()
-                           .c_str());
-      prepicked_compaction->compaction->ReleaseCompactionFiles(
-          Status::Incomplete(Status::SubCode::kManualCompactionPaused));
-      delete prepicked_compaction->compaction;
-    } else {
-      JobContext job_context(next_job_id_.fetch_add(1), true);
-      // This call will unlock/lock the mutex to wait for current running
-      // IngestExternalFile() calls to finish.
-      WaitForIngestFile();
+    // This call will unlock/lock the mutex to wait for current running
+    // IngestExternalFile() calls to finish.
+    WaitForIngestFile();
 
-      num_running_compactions_++;
+    num_running_compactions_++;
 
-      std::unique_ptr<std::list<uint64_t>::iterator>
-          pending_outputs_inserted_elem(new std::list<uint64_t>::iterator(
-              CaptureCurrentFileNumberInPendingOutputs()));
+    std::unique_ptr<std::list<uint64_t>::iterator>
+        pending_outputs_inserted_elem(new std::list<uint64_t>::iterator(
+            CaptureCurrentFileNumberInPendingOutputs()));
 
-      assert((bg_thread_pri == Env::Priority::BOTTOM &&
-              bg_bottom_compaction_scheduled_) ||
-             (bg_thread_pri == Env::Priority::LOW && bg_compaction_scheduled_));
-      Status s = BackgroundCompaction(&made_progress, &job_context, &log_buffer,
-                                      prepicked_compaction, bg_thread_pri);
-      TEST_SYNC_POINT("BackgroundCallCompaction:1");
-      if (s.IsBusy()) {
-        bg_cv_.SignalAll();  // In case a waiter can proceed despite the error
-        mutex_.Unlock();
-        immutable_db_options_.clock->SleepForMicroseconds(
-            10000);  // prevent hot loop
-        mutex_.Lock();
-      } else if (!s.ok() && !s.IsShutdownInProgress() &&
-                 !s.IsManualCompactionPaused() && !s.IsColumnFamilyDropped()) {
-        // Wait a little bit before retrying background compaction in
-        // case this is an environmental problem and we do not want to
-        // chew up resources for failed compactions for the duration of
-        // the problem.
-        uint64_t error_cnt =
-            default_cf_internal_stats_->BumpAndGetBackgroundErrorCount();
-        bg_cv_.SignalAll();  // In case a waiter can proceed despite the error
-        mutex_.Unlock();
-        log_buffer.FlushBufferToLog();
-        ROCKS_LOG_ERROR(immutable_db_options_.info_log,
-                        "Waiting after background compaction error: %s, "
-                        "Accumulated background error counts: %" PRIu64,
-                        s.ToString().c_str(), error_cnt);
-        LogFlush(immutable_db_options_.info_log);
-        immutable_db_options_.clock->SleepForMicroseconds(1000000);
-        mutex_.Lock();
-      } else if (s.IsManualCompactionPaused()) {
-        assert(prepicked_compaction);
-        ManualCompactionState* m =
-            prepicked_compaction->manual_compaction_state;
-        assert(m);
-        ROCKS_LOG_BUFFER(&log_buffer, "[%s] [JOB %d] Manual compaction paused",
-                         m->cfd->GetName().c_str(), job_context.job_id);
-      }
-
-      ReleaseFileNumberFromPendingOutputs(pending_outputs_inserted_elem);
-
-      // If compaction failed, we want to delete all temporary files that we
-      // might have created (they might not be all recorded in job_context in
-      // case of a failure). Thus, we force full scan in FindObsoleteFiles()
-      FindObsoleteFiles(&job_context, !s.ok() && !s.IsShutdownInProgress() &&
-                                          !s.IsManualCompactionPaused() &&
-                                          !s.IsColumnFamilyDropped() &&
-                                          !s.IsBusy());
-      TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:FoundObsoleteFiles");
-
-      // delete unnecessary files if any, this is done outside the mutex
-      if (job_context.HaveSomethingToClean() ||
-          job_context.HaveSomethingToDelete() || !log_buffer.IsEmpty()) {
-        mutex_.Unlock();
-        // Have to flush the info logs before bg_compaction_scheduled_--
-        // because if bg_flush_scheduled_ becomes 0 and the lock is
-        // released, the deconstructor of DB can kick in and destroy all the
-        // states of DB so info_log might not be available after that point.
-        // It also applies to access other states that DB owns.
-        log_buffer.FlushBufferToLog();
-        if (job_context.HaveSomethingToDelete()) {
-          PurgeObsoleteFiles(job_context);
-          TEST_SYNC_POINT(
-              "DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles");
-        }
-        job_context.Clean();
-        mutex_.Lock();
-      }
-
-      assert(num_running_compactions_ > 0);
-      num_running_compactions_--;
+    assert((bg_thread_pri == Env::Priority::BOTTOM &&
+            bg_bottom_compaction_scheduled_) ||
+           (bg_thread_pri == Env::Priority::LOW && bg_compaction_scheduled_));
+    Status s = BackgroundCompaction(&made_progress, &job_context, &log_buffer,
+                                    prepicked_compaction, bg_thread_pri);
+    TEST_SYNC_POINT("BackgroundCallCompaction:1");
+    if (s.IsBusy()) {
+      bg_cv_.SignalAll();  // In case a waiter can proceed despite the error
+      mutex_.Unlock();
+      immutable_db_options_.clock->SleepForMicroseconds(
+          10000);  // prevent hot loop
+      mutex_.Lock();
+    } else if (!s.ok() && !s.IsShutdownInProgress() &&
+               !s.IsManualCompactionPaused() && !s.IsColumnFamilyDropped()) {
+      // Wait a little bit before retrying background compaction in
+      // case this is an environmental problem and we do not want to
+      // chew up resources for failed compactions for the duration of
+      // the problem.
+      uint64_t error_cnt =
+          default_cf_internal_stats_->BumpAndGetBackgroundErrorCount();
+      bg_cv_.SignalAll();  // In case a waiter can proceed despite the error
+      mutex_.Unlock();
+      log_buffer.FlushBufferToLog();
+      ROCKS_LOG_ERROR(immutable_db_options_.info_log,
+                      "Waiting after background compaction error: %s, "
+                      "Accumulated background error counts: %" PRIu64,
+                      s.ToString().c_str(), error_cnt);
+      LogFlush(immutable_db_options_.info_log);
+      immutable_db_options_.clock->SleepForMicroseconds(1000000);
+      mutex_.Lock();
+    } else if (s.IsManualCompactionPaused()) {
+      assert(prepicked_compaction);
+      ManualCompactionState* m = prepicked_compaction->manual_compaction_state;
+      assert(m);
+      ROCKS_LOG_BUFFER(&log_buffer, "[%s] [JOB %d] Manual compaction paused",
+                       m->cfd->GetName().c_str(), job_context.job_id);
     }
 
+    ReleaseFileNumberFromPendingOutputs(pending_outputs_inserted_elem);
+
+    // If compaction failed, we want to delete all temporary files that we
+    // might have created (they might not be all recorded in job_context in
+    // case of a failure). Thus, we force full scan in FindObsoleteFiles()
+    FindObsoleteFiles(&job_context, !s.ok() && !s.IsShutdownInProgress() &&
+                                        !s.IsManualCompactionPaused() &&
+                                        !s.IsColumnFamilyDropped() &&
+                                        !s.IsBusy());
+    TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:FoundObsoleteFiles");
+
+    // delete unnecessary files if any, this is done outside the mutex
+    if (job_context.HaveSomethingToClean() ||
+        job_context.HaveSomethingToDelete() || !log_buffer.IsEmpty()) {
+      mutex_.Unlock();
+      // Have to flush the info logs before bg_compaction_scheduled_--
+      // because if bg_flush_scheduled_ becomes 0 and the lock is
+      // released, the deconstructor of DB can kick in and destroy all the
+      // states of DB so info_log might not be available after that point.
+      // It also applies to access other states that DB owns.
+      log_buffer.FlushBufferToLog();
+      if (job_context.HaveSomethingToDelete()) {
+        PurgeObsoleteFiles(job_context);
+        TEST_SYNC_POINT("DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles");
+      }
+      job_context.Clean();
+      mutex_.Lock();
+    }
+
+    assert(num_running_compactions_ > 0);
+    num_running_compactions_--;
+
     if (bg_thread_pri == Env::Priority::LOW) {
       bg_compaction_scheduled_--;
     } else {
@@ -2958,8 +2992,6 @@ void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
       bg_bottom_compaction_scheduled_--;
     }
 
-    versions_->GetColumnFamilySet()->FreeDeadColumnFamilies();
-
     // See if there's more work to be done
     MaybeScheduleFlushOrCompaction();
 
@@ -3055,6 +3087,8 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
     manual_compaction->in_progress = true;
   }
 
+  TEST_SYNC_POINT("DBImpl::BackgroundCompaction:InProgress");
+
   std::unique_ptr<TaskLimiterToken> task_token;
 
   // InternalKey manual_end_storage;

db/db_impl/db_impl_files.cc

@@ -23,11 +23,7 @@
 namespace ROCKSDB_NAMESPACE {
 
 uint64_t DBImpl::MinLogNumberToKeep() {
-  if (allow_2pc()) {
-    return versions_->min_log_number_to_keep_2pc();
-  } else {
-    return versions_->MinLogNumberWithUnflushedData();
-  }
+  return versions_->min_log_number_to_keep();
 }
 
 uint64_t DBImpl::MinObsoleteSstNumberToKeep() {
@@ -224,7 +220,6 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
     }
 
     // Add log files in wal_dir
-
     if (!immutable_db_options_.IsWalDirSameAsDBPath(dbname_)) {
       std::vector<std::string> log_files;
       Status s = env_->GetChildren(immutable_db_options_.wal_dir, &log_files);
@@ -234,6 +229,7 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
             log_file, immutable_db_options_.wal_dir);
       }
     }
+
     // Add info log files in db_log_dir
     if (!immutable_db_options_.db_log_dir.empty() &&
         immutable_db_options_.db_log_dir != dbname_) {

db/db_impl/db_impl_open.cc

@@ -866,6 +866,11 @@ Status DBImpl::RecoverLogFiles(const std::vector<uint64_t>& wal_numbers,
   bool flushed = false;
   uint64_t corrupted_wal_number = kMaxSequenceNumber;
   uint64_t min_wal_number = MinLogNumberToKeep();
+  if (!allow_2pc()) {
+    // In non-2pc mode, we skip WALs that do not back unflushed data.
+    min_wal_number =
+        std::max(min_wal_number, versions_->MinLogNumberWithUnflushedData());
+  }
   for (auto wal_number : wal_numbers) {
     if (wal_number < min_wal_number) {
       ROCKS_LOG_INFO(immutable_db_options_.info_log,
@@ -1270,9 +1275,16 @@ Status DBImpl::RecoverLogFiles(const std::vector<uint64_t>& wal_numbers,
       }
 
       std::unique_ptr<VersionEdit> wal_deletion;
-      if (immutable_db_options_.track_and_verify_wals_in_manifest) {
-        wal_deletion.reset(new VersionEdit);
-        wal_deletion->DeleteWalsBefore(max_wal_number + 1);
+      if (flushed) {
+        wal_deletion = std::make_unique<VersionEdit>();
+        if (immutable_db_options_.track_and_verify_wals_in_manifest) {
+          wal_deletion->DeleteWalsBefore(max_wal_number + 1);
+        }
+        if (!allow_2pc()) {
+          // In non-2pc mode, flushing the memtables of the column families
+          // means we can advance min_log_number_to_keep.
+          wal_deletion->SetMinLogNumberToKeep(max_wal_number + 1);
+        }
         edit_lists.back().push_back(wal_deletion.get());
       }
 
@@ -1351,7 +1363,14 @@ Status DBImpl::RestoreAliveLogFiles(const std::vector<uint64_t>& wal_numbers) {
   // FindObsoleteFiles()
   total_log_size_ = 0;
   log_empty_ = false;
+  uint64_t min_wal_with_unflushed_data =
+      versions_->MinLogNumberWithUnflushedData();
   for (auto wal_number : wal_numbers) {
+    if (!allow_2pc() && wal_number < min_wal_with_unflushed_data) {
+      // In non-2pc mode, the WAL files not backing unflushed data are not
+      // alive, thus should not be added to the alive_log_files_.
+      continue;
+    }
     // We preallocate space for wals, but then after a crash and restart, those
     // preallocated space are not needed anymore. It is likely only the last
     // log has such preallocated space, so we only truncate for the last log.
@@ -1364,6 +1383,7 @@ Status DBImpl::RestoreAliveLogFiles(const std::vector<uint64_t>& wal_numbers) {
     total_log_size_ += log.size;
     alive_log_files_.push_back(log);
   }
+  alive_log_files_tail_ = alive_log_files_.rbegin();
   if (two_write_queues_) {
     log_write_mutex_.Unlock();
   }
@@ -1709,6 +1729,7 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
       }
       impl->alive_log_files_.push_back(
           DBImpl::LogFileNumberSize(impl->logfile_number_));
+      impl->alive_log_files_tail_ = impl->alive_log_files_.rbegin();
       if (impl->two_write_queues_) {
         impl->log_write_mutex_.Unlock();
       }
@@ -1729,7 +1750,8 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
         WriteOptions write_options;
         uint64_t log_used, log_size;
         log::Writer* log_writer = impl->logs_.back().writer;
-        s = impl->WriteToWAL(empty_batch, log_writer, &log_used, &log_size);
+        s = impl->WriteToWAL(empty_batch, log_writer, &log_used, &log_size,
+                             /*with_db_mutex==*/true);
         if (s.ok()) {
           // Need to fsync, otherwise it might get lost after a power reset.
           s = impl->FlushWAL(false);
@@ -1889,8 +1911,9 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
                    persist_options_status.ToString().c_str());
   }
   if (s.ok()) {
-    impl->StartPeriodicWorkScheduler();
-  } else {
+    s = impl->StartPeriodicWorkScheduler();
+  }
+  if (!s.ok()) {
     for (auto* h : *handles) {
       delete h;
     }

db/db_impl/db_impl_write.cc

@@ -1147,8 +1147,18 @@ WriteBatch* DBImpl::MergeBatch(const WriteThread::WriteGroup& write_group,
 // write thread. Otherwise this must be called holding log_write_mutex_.
 IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
                             log::Writer* log_writer, uint64_t* log_used,
-                            uint64_t* log_size) {
+                            uint64_t* log_size,
+                            bool with_db_mutex, bool with_log_mutex) {
   assert(log_size != nullptr);
+
+  // Assert mutex explicitly.
+  if (with_db_mutex) {
+    mutex_.AssertHeld();
+  } else if (two_write_queues_) {
+    log_write_mutex_.AssertHeld();
+    assert(with_log_mutex);
+  }
+
   Slice log_entry = WriteBatchInternal::Contents(&merged_batch);
   *log_size = log_entry.size();
   // When two_write_queues_ WriteToWAL has to be protected from concurretn calls
@@ -1171,9 +1181,12 @@ IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
     *log_used = logfile_number_;
   }
   total_log_size_ += log_entry.size();
-  // TODO(myabandeh): it might be unsafe to access alive_log_files_.back() here
-  // since alive_log_files_ might be modified concurrently
-  alive_log_files_.back().AddSize(log_entry.size());
+  if (with_db_mutex || with_log_mutex) {
+    assert(alive_log_files_tail_ == alive_log_files_.rbegin());
+    assert(alive_log_files_tail_ != alive_log_files_.rend());
+  }
+  LogFileNumberSize& last_alive_log = *alive_log_files_tail_;
+  last_alive_log.AddSize(*log_size);
   log_empty_ = false;
   return io_s;
 }
@@ -1183,6 +1196,7 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
                             bool need_log_sync, bool need_log_dir_sync,
                             SequenceNumber sequence) {
   IOStatus io_s;
+  assert(!two_write_queues_);
   assert(!write_group.leader->disable_wal);
   // Same holds for all in the batch group
   size_t write_with_wal = 0;
@@ -1270,6 +1284,7 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
     SequenceNumber* last_sequence, size_t seq_inc) {
   IOStatus io_s;
 
+  assert(two_write_queues_ || immutable_db_options_.unordered_write);
   assert(!write_group.leader->disable_wal);
   // Same holds for all in the batch group
   WriteBatch tmp_batch;
@@ -1294,7 +1309,8 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
 
   log::Writer* log_writer = logs_.back().writer;
   uint64_t log_size;
-  io_s = WriteToWAL(*merged_batch, log_writer, log_used, &log_size);
+  io_s = WriteToWAL(*merged_batch, log_writer, log_used, &log_size,
+                    /*with_db_mutex=*/false, /*with_log_mutex=*/true);
   if (to_be_cached_state) {
     cached_recoverable_state_ = *to_be_cached_state;
     cached_recoverable_state_empty_ = false;
@@ -1948,6 +1964,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
       log_dir_synced_ = false;
       logs_.emplace_back(logfile_number_, new_log);
       alive_log_files_.push_back(LogFileNumberSize(logfile_number_));
+      alive_log_files_tail_ = alive_log_files_.rbegin();
     }
     log_write_mutex_.Unlock();
   }

db/db_inplace_update_test.cc

@@ -169,6 +169,36 @@ TEST_F(DBTestInPlaceUpdate, InPlaceUpdateCallbackNoAction) {
     ASSERT_EQ(Get(1, "key"), "NOT_FOUND");
   } while (ChangeCompactOptions());
 }
+
+TEST_F(DBTestInPlaceUpdate, InPlaceUpdateAndSnapshot) {
+  do {
+    Options options = CurrentOptions();
+    options.create_if_missing = true;
+    options.inplace_update_support = true;
+    options.env = env_;
+    options.write_buffer_size = 100000;
+    options.allow_concurrent_memtable_write = false;
+    Reopen(options);
+    CreateAndReopenWithCF({"pikachu"}, options);
+
+    // Update key with values of smaller size, and
+    // run GetSnapshot and ReleaseSnapshot
+    int numValues = 2;
+    for (int i = numValues; i > 0; i--) {
+      const Snapshot* s = db_->GetSnapshot();
+      ASSERT_EQ(nullptr, s);
+      std::string value = DummyString(i, 'a');
+      ASSERT_OK(Put(1, "key", value));
+      ASSERT_EQ(value, Get(1, "key"));
+      // release s (nullptr)
+      db_->ReleaseSnapshot(s);
+    }
+
+    // Only 1 instance for that key.
+    validateNumberOfEntries(1, 1);
+  } while (ChangeCompactOptions());
+}
+
 }  // namespace ROCKSDB_NAMESPACE
 
 int main(int argc, char** argv) {

db/db_range_del_test.cc

@@ -1724,6 +1724,34 @@ TEST_F(DBRangeDelTest, OverlappedKeys) {
   ASSERT_EQ(0, NumTableFilesAtLevel(1));
 }
 
+TEST_F(DBRangeDelTest, IteratorRefresh) {
+  // Refreshing an iterator after a range tombstone is added should cause the
+  // deleted range of keys to disappear.
+  for (bool sv_changed : {false, true}) {
+    ASSERT_OK(db_->Put(WriteOptions(), "key1", "value1"));
+    ASSERT_OK(db_->Put(WriteOptions(), "key2", "value2"));
+
+    auto* iter = db_->NewIterator(ReadOptions());
+    ASSERT_OK(iter->status());
+
+    ASSERT_OK(db_->DeleteRange(WriteOptions(), db_->DefaultColumnFamily(),
+                               "key2", "key3"));
+
+    if (sv_changed) {
+      ASSERT_OK(db_->Flush(FlushOptions()));
+    }
+
+    ASSERT_OK(iter->Refresh());
+    ASSERT_OK(iter->status());
+    iter->SeekToFirst();
+    ASSERT_EQ("key1", iter->key());
+    iter->Next();
+    ASSERT_FALSE(iter->Valid());
+
+    delete iter;
+  }
+}
+
 #endif  // ROCKSDB_LITE
 
 }  // namespace ROCKSDB_NAMESPACE

db/db_wal_test.cc

@@ -1491,6 +1491,93 @@ TEST_F(DBWALTest, kPointInTimeRecoveryCFConsistency) {
   ASSERT_NOK(TryReopenWithColumnFamilies({"default", "one", "two"}, options));
 }
 
+TEST_F(DBWALTest, RaceInstallFlushResultsWithWalObsoletion) {
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.track_and_verify_wals_in_manifest = true;
+  // The following make sure there are two bg flush threads.
+  options.max_background_jobs = 8;
+
+  const std::string cf1_name("cf1");
+  CreateAndReopenWithCF({cf1_name}, options);
+  assert(handles_.size() == 2);
+
+  {
+    dbfull()->TEST_LockMutex();
+    ASSERT_LE(2, dbfull()->GetBGJobLimits().max_flushes);
+    dbfull()->TEST_UnlockMutex();
+  }
+
+  ASSERT_OK(dbfull()->PauseBackgroundWork());
+
+  ASSERT_OK(db_->Put(WriteOptions(), handles_[1], "foo", "value"));
+  ASSERT_OK(db_->Put(WriteOptions(), "foo", "value"));
+
+  ASSERT_OK(dbfull()->TEST_FlushMemTable(false, true, handles_[1]));
+
+  ASSERT_OK(db_->Put(WriteOptions(), "foo", "value"));
+  ASSERT_OK(dbfull()->TEST_FlushMemTable(false, true, handles_[0]));
+
+  bool called = false;
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  // This callback will be called when the first bg flush thread reaches the
+  // point before entering the MANIFEST write queue after flushing the SST
+  // file.
+  // The purpose of the sync points here is to ensure both bg flush threads
+  // finish computing `min_wal_number_to_keep` before any of them updates the
+  // `log_number` for the column family that's being flushed.
+  SyncPoint::GetInstance()->SetCallBack(
+      "MemTableList::TryInstallMemtableFlushResults:AfterComputeMinWalToKeep",
+      [&](void* /*arg*/) {
+        dbfull()->mutex()->AssertHeld();
+        if (!called) {
+          // We are the first bg flush thread in the MANIFEST write queue.
+          // We set up the dependency between sync points for two threads that
+          // will be executing the same code.
+          // For the interleaving of events, see
+          // https://github.com/facebook/rocksdb/pull/9715.
+          // bg flush thread1 will release the db mutex while in the MANIFEST
+          // write queue. In the meantime, bg flush thread2 locks db mutex and
+          // computes the min_wal_number_to_keep (before thread1 writes to
+          // MANIFEST thus before cf1->log_number is updated). Bg thread2 joins
+          // the MANIFEST write queue afterwards and bg flush thread1 proceeds
+          // with writing to MANIFEST.
+          called = true;
+          SyncPoint::GetInstance()->LoadDependency({
+              {"VersionSet::LogAndApply:WriteManifestStart",
+               "DBWALTest::RaceInstallFlushResultsWithWalObsoletion:BgFlush2"},
+              {"DBWALTest::RaceInstallFlushResultsWithWalObsoletion:BgFlush2",
+               "VersionSet::LogAndApply:WriteManifest"},
+          });
+        } else {
+          // The other bg flush thread has already been in the MANIFEST write
+          // queue, and we are after.
+          TEST_SYNC_POINT(
+              "DBWALTest::RaceInstallFlushResultsWithWalObsoletion:BgFlush2");
+        }
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  ASSERT_OK(dbfull()->ContinueBackgroundWork());
+
+  ASSERT_OK(dbfull()->TEST_WaitForFlushMemTable(handles_[0]));
+  ASSERT_OK(dbfull()->TEST_WaitForFlushMemTable(handles_[1]));
+
+  ASSERT_TRUE(called);
+
+  Close();
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  DB* db1 = nullptr;
+  Status s = DB::OpenForReadOnly(options, dbname_, &db1);
+  ASSERT_OK(s);
+  assert(db1);
+  delete db1;
+}
+
 // Test scope:
 // - We expect to open data store under all circumstances
 // - We expect only data upto the point where the first error was encountered

db/event_helpers.cc

@@ -95,8 +95,9 @@ void EventHelpers::LogAndNotifyTableFileCreationFinished(
     jwriter << "cf_name" << cf_name << "job" << job_id << "event"
             << "table_file_creation"
             << "file_number" << fd.GetNumber() << "file_size"
-            << fd.GetFileSize() << "file_checksum" << file_checksum
-            << "file_checksum_func_name" << file_checksum_func_name;
+            << fd.GetFileSize() << "file_checksum"
+            << Slice(file_checksum).ToString(true) << "file_checksum_func_name"
+            << file_checksum_func_name;
 
     // table_properties
     {

db/external_sst_file_ingestion_job.cc

@@ -777,10 +777,11 @@ Status ExternalSstFileIngestionJob::AssignLevelAndSeqnoForIngestedFile(
         const std::vector<FileMetaData*>& level_files =
             vstorage->LevelFiles(lvl);
         const SequenceNumber level_largest_seqno =
-            (*max_element(level_files.begin(), level_files.end(),
-                          [](FileMetaData* f1, FileMetaData* f2) {
-                            return f1->fd.largest_seqno < f2->fd.largest_seqno;
-                          }))
+            (*std::max_element(level_files.begin(), level_files.end(),
+                               [](FileMetaData* f1, FileMetaData* f2) {
+                                 return f1->fd.largest_seqno <
+                                        f2->fd.largest_seqno;
+                               }))
                 ->fd.largest_seqno;
         // should only assign seqno to current level's largest seqno when
         // the file fits

db/flush_job.cc

@@ -354,7 +354,7 @@ Status FlushJob::MemPurge() {
 
   // Measure purging time.
   const uint64_t start_micros = clock_->NowMicros();
-  const uint64_t start_cpu_micros = clock_->CPUNanos() / 1000;
+  const uint64_t start_cpu_micros = clock_->CPUMicros();
 
   MemTable* new_mem = nullptr;
   // For performance/log investigation purposes:
@@ -606,7 +606,7 @@ Status FlushJob::MemPurge() {
     TEST_SYNC_POINT("DBImpl::FlushJob:MemPurgeUnsuccessful");
   }
   const uint64_t micros = clock_->NowMicros() - start_micros;
-  const uint64_t cpu_micros = clock_->CPUNanos() / 1000 - start_cpu_micros;
+  const uint64_t cpu_micros = clock_->CPUMicros() - start_cpu_micros;
   ROCKS_LOG_INFO(db_options_.info_log,
                  "[%s] [JOB %d] Mempurge lasted %" PRIu64
                  " microseconds, and %" PRIu64
@@ -792,7 +792,7 @@ Status FlushJob::WriteLevel0Table() {
       ThreadStatus::STAGE_FLUSH_WRITE_L0);
   db_mutex_->AssertHeld();
   const uint64_t start_micros = clock_->NowMicros();
-  const uint64_t start_cpu_micros = clock_->CPUNanos() / 1000;
+  const uint64_t start_cpu_micros = clock_->CPUMicros();
   Status s;
 
   std::vector<BlobFileAddition> blob_file_additions;
@@ -979,7 +979,7 @@ Status FlushJob::WriteLevel0Table() {
   // Note that here we treat flush as level 0 compaction in internal stats
   InternalStats::CompactionStats stats(CompactionReason::kFlush, 1);
   const uint64_t micros = clock_->NowMicros() - start_micros;
-  const uint64_t cpu_micros = clock_->CPUNanos() / 1000 - start_cpu_micros;
+  const uint64_t cpu_micros = clock_->CPUMicros() - start_cpu_micros;
   stats.micros = micros;
   stats.cpu_micros = cpu_micros;
 

db/memtable_list.cc

@@ -494,8 +494,8 @@ Status MemTableList::TryInstallMemtableFlushResults(
     // TODO(myabandeh): Not sure how batch_count could be 0 here.
     if (batch_count > 0) {
       uint64_t min_wal_number_to_keep = 0;
+      assert(edit_list.size() > 0);
       if (vset->db_options()->allow_2pc) {
-        assert(edit_list.size() > 0);
         // Note that if mempurge is successful, the edit_list will
         // not be applicable (contains info of new min_log number to keep,
         // and level 0 file path of SST file created during normal flush,
@@ -504,23 +504,26 @@ Status MemTableList::TryInstallMemtableFlushResults(
         min_wal_number_to_keep = PrecomputeMinLogNumberToKeep2PC(
             vset, *cfd, edit_list, memtables_to_flush, prep_tracker);
 
-        // We piggyback the information of  earliest log file to keep in the
+        // We piggyback the information of earliest log file to keep in the
         // manifest entry for the last file flushed.
-        edit_list.back()->SetMinLogNumberToKeep(min_wal_number_to_keep);
+      } else {
+        min_wal_number_to_keep =
+            PrecomputeMinLogNumberToKeepNon2PC(vset, *cfd, edit_list);
       }
+      edit_list.back()->SetMinLogNumberToKeep(min_wal_number_to_keep);
 
       std::unique_ptr<VersionEdit> wal_deletion;
       if (vset->db_options()->track_and_verify_wals_in_manifest) {
-        if (!vset->db_options()->allow_2pc) {
-          min_wal_number_to_keep =
-              PrecomputeMinLogNumberToKeepNon2PC(vset, *cfd, edit_list);
-        }
         if (min_wal_number_to_keep >
             vset->GetWalSet().GetMinWalNumberToKeep()) {
           wal_deletion.reset(new VersionEdit);
           wal_deletion->DeleteWalsBefore(min_wal_number_to_keep);
           edit_list.push_back(wal_deletion.get());
         }
+        TEST_SYNC_POINT_CALLBACK(
+            "MemTableList::TryInstallMemtableFlushResults:"
+            "AfterComputeMinWalToKeep",
+            nullptr);
       }
 
       const auto manifest_write_cb = [this, cfd, batch_count, log_buffer,
@@ -805,15 +808,14 @@ Status InstallMemtableAtomicFlushResults(
   if (vset->db_options()->allow_2pc) {
     min_wal_number_to_keep = PrecomputeMinLogNumberToKeep2PC(
         vset, cfds, edit_lists, mems_list, prep_tracker);
-    edit_lists.back().back()->SetMinLogNumberToKeep(min_wal_number_to_keep);
+  } else {
+    min_wal_number_to_keep =
+        PrecomputeMinLogNumberToKeepNon2PC(vset, cfds, edit_lists);
   }
+  edit_lists.back().back()->SetMinLogNumberToKeep(min_wal_number_to_keep);
 
   std::unique_ptr<VersionEdit> wal_deletion;
   if (vset->db_options()->track_and_verify_wals_in_manifest) {
-    if (!vset->db_options()->allow_2pc) {
-      min_wal_number_to_keep =
-          PrecomputeMinLogNumberToKeepNon2PC(vset, cfds, edit_lists);
-    }
     if (min_wal_number_to_keep > vset->GetWalSet().GetMinWalNumberToKeep()) {
       wal_deletion.reset(new VersionEdit);
       wal_deletion->DeleteWalsBefore(min_wal_number_to_keep);

db/periodic_work_scheduler.cc

@@ -16,31 +16,41 @@ PeriodicWorkScheduler::PeriodicWorkScheduler(
   timer = std::unique_ptr<Timer>(new Timer(clock.get()));
 }
 
-void PeriodicWorkScheduler::Register(DBImpl* dbi,
-                                     unsigned int stats_dump_period_sec,
-                                     unsigned int stats_persist_period_sec) {
+Status PeriodicWorkScheduler::Register(DBImpl* dbi,
+                                       unsigned int stats_dump_period_sec,
+                                       unsigned int stats_persist_period_sec) {
   MutexLock l(&timer_mu_);
   static std::atomic<uint64_t> initial_delay(0);
   timer->Start();
   if (stats_dump_period_sec > 0) {
-    timer->Add([dbi]() { dbi->DumpStats(); }, GetTaskName(dbi, "dump_st"),
-               initial_delay.fetch_add(1) %
-                   static_cast<uint64_t>(stats_dump_period_sec) *
-                   kMicrosInSecond,
-               static_cast<uint64_t>(stats_dump_period_sec) * kMicrosInSecond);
+    bool succeeded = timer->Add(
+        [dbi]() { dbi->DumpStats(); }, GetTaskName(dbi, "dump_st"),
+        initial_delay.fetch_add(1) %
+            static_cast<uint64_t>(stats_dump_period_sec) * kMicrosInSecond,
+        static_cast<uint64_t>(stats_dump_period_sec) * kMicrosInSecond);
+    if (!succeeded) {
+      return Status::Aborted("Unable to add periodic task DumpStats");
+    }
   }
   if (stats_persist_period_sec > 0) {
-    timer->Add(
+    bool succeeded = timer->Add(
         [dbi]() { dbi->PersistStats(); }, GetTaskName(dbi, "pst_st"),
         initial_delay.fetch_add(1) %
             static_cast<uint64_t>(stats_persist_period_sec) * kMicrosInSecond,
         static_cast<uint64_t>(stats_persist_period_sec) * kMicrosInSecond);
+    if (!succeeded) {
+      return Status::Aborted("Unable to add periodic task PersistStats");
+    }
   }
-  timer->Add([dbi]() { dbi->FlushInfoLog(); },
-             GetTaskName(dbi, "flush_info_log"),
-             initial_delay.fetch_add(1) % kDefaultFlushInfoLogPeriodSec *
-                 kMicrosInSecond,
-             kDefaultFlushInfoLogPeriodSec * kMicrosInSecond);
+  bool succeeded = timer->Add(
+      [dbi]() { dbi->FlushInfoLog(); }, GetTaskName(dbi, "flush_info_log"),
+      initial_delay.fetch_add(1) % kDefaultFlushInfoLogPeriodSec *
+          kMicrosInSecond,
+      kDefaultFlushInfoLogPeriodSec * kMicrosInSecond);
+  if (!succeeded) {
+    return Status::Aborted("Unable to add periodic task PersistStats");
+  }
+  return Status::OK();
 }
 
 void PeriodicWorkScheduler::Unregister(DBImpl* dbi) {

db/periodic_work_scheduler.h

@@ -30,8 +30,8 @@ class PeriodicWorkScheduler {
   PeriodicWorkScheduler& operator=(const PeriodicWorkScheduler&) = delete;
   PeriodicWorkScheduler& operator=(PeriodicWorkScheduler&&) = delete;
 
-  void Register(DBImpl* dbi, unsigned int stats_dump_period_sec,
-                unsigned int stats_persist_period_sec);
+  Status Register(DBImpl* dbi, unsigned int stats_dump_period_sec,
+                  unsigned int stats_persist_period_sec);
 
   void Unregister(DBImpl* dbi);
 

db/table_cache.cc

@@ -114,15 +114,18 @@ Status TableCache::GetTableReader(
   if (s.ok()) {
     s = ioptions_.fs->NewRandomAccessFile(fname, fopts, &file, nullptr);
   }
-  RecordTick(ioptions_.stats, NO_FILE_OPENS);
-  if (s.IsPathNotFound()) {
+  if (s.ok()) {
+    RecordTick(ioptions_.stats, NO_FILE_OPENS);
+  } else if (s.IsPathNotFound()) {
     fname = Rocks2LevelTableFileName(fname);
     s = PrepareIOFromReadOptions(ro, ioptions_.clock, fopts.io_options);
     if (s.ok()) {
       s = ioptions_.fs->NewRandomAccessFile(fname, file_options, &file,
                                             nullptr);
     }
-    RecordTick(ioptions_.stats, NO_FILE_OPENS);
+    if (s.ok()) {
+      RecordTick(ioptions_.stats, NO_FILE_OPENS);
+    }
   }
 
   if (s.ok()) {

db/version_edit_handler.cc

@@ -394,7 +394,7 @@ void VersionEditHandler::CheckIterationResult(const log::Reader& reader,
   if (s->ok()) {
     version_set_->GetColumnFamilySet()->UpdateMaxColumnFamily(
         version_edit_params_.max_column_family_);
-    version_set_->MarkMinLogNumberToKeep2PC(
+    version_set_->MarkMinLogNumberToKeep(
         version_edit_params_.min_log_number_to_keep_);
     version_set_->MarkFileNumberUsed(version_edit_params_.prev_log_number_);
     version_set_->MarkFileNumberUsed(version_edit_params_.log_number_);
@@ -970,12 +970,11 @@ void DumpManifestHandler::CheckIterationResult(const log::Reader& reader,
   fprintf(stdout,
           "next_file_number %" PRIu64 " last_sequence %" PRIu64
           "  prev_log_number %" PRIu64 " max_column_family %" PRIu32
-          " min_log_number_to_keep "
-          "%" PRIu64 "\n",
+          " min_log_number_to_keep %" PRIu64 "\n",
           version_set_->current_next_file_number(),
           version_set_->LastSequence(), version_set_->prev_log_number(),
           version_set_->column_family_set_->GetMaxColumnFamily(),
-          version_set_->min_log_number_to_keep_2pc());
+          version_set_->min_log_number_to_keep());
 }
 
 }  // namespace ROCKSDB_NAMESPACE

db/version_set.cc

@@ -4141,7 +4141,7 @@ void VersionSet::Reset() {
   }
   db_id_.clear();
   next_file_number_.store(2);
-  min_log_number_to_keep_2pc_.store(0);
+  min_log_number_to_keep_.store(0);
   manifest_file_number_ = 0;
   options_file_number_ = 0;
   pending_manifest_file_number_ = 0;
@@ -4610,8 +4610,7 @@ Status VersionSet::ProcessManifestWrites(
       }
 
       if (last_min_log_number_to_keep != 0) {
-        // Should only be set in 2PC mode.
-        MarkMinLogNumberToKeep2PC(last_min_log_number_to_keep);
+        MarkMinLogNumberToKeep(last_min_log_number_to_keep);
       }
 
       for (int i = 0; i < static_cast<int>(versions.size()); ++i) {
@@ -4965,7 +4964,7 @@ Status VersionSet::Recover(
         ",min_log_number_to_keep is %" PRIu64 "\n",
         manifest_path.c_str(), manifest_file_number_, next_file_number_.load(),
         last_sequence_.load(), log_number, prev_log_number_,
-        column_family_set_->GetMaxColumnFamily(), min_log_number_to_keep_2pc());
+        column_family_set_->GetMaxColumnFamily(), min_log_number_to_keep());
 
     for (auto cfd : *column_family_set_) {
       if (cfd->IsDropped()) {
@@ -5378,9 +5377,9 @@ void VersionSet::MarkFileNumberUsed(uint64_t number) {
 }
 // Called only either from ::LogAndApply which is protected by mutex or during
 // recovery which is single-threaded.
-void VersionSet::MarkMinLogNumberToKeep2PC(uint64_t number) {
-  if (min_log_number_to_keep_2pc_.load(std::memory_order_relaxed) < number) {
-    min_log_number_to_keep_2pc_.store(number, std::memory_order_relaxed);
+void VersionSet::MarkMinLogNumberToKeep(uint64_t number) {
+  if (min_log_number_to_keep_.load(std::memory_order_relaxed) < number) {
+    min_log_number_to_keep_.store(number, std::memory_order_relaxed);
   }
 }
 
@@ -5506,7 +5505,7 @@ Status VersionSet::WriteCurrentStateToManifest(
         // min_log_number_to_keep is for the whole db, not for specific column family.
         // So it does not need to be set for every column family, just need to be set once.
         // Since default CF can never be dropped, we set the min_log to the default CF here.
-        uint64_t min_log = min_log_number_to_keep_2pc();
+        uint64_t min_log = min_log_number_to_keep();
         if (min_log != 0) {
           edit.SetMinLogNumberToKeep(min_log);
         }

db/version_set.h

@@ -1128,8 +1128,8 @@ class VersionSet {
 
   uint64_t current_next_file_number() const { return next_file_number_.load(); }
 
-  uint64_t min_log_number_to_keep_2pc() const {
-    return min_log_number_to_keep_2pc_.load();
+  uint64_t min_log_number_to_keep() const {
+    return min_log_number_to_keep_.load();
   }
 
   // Allocate and return a new file number
@@ -1187,7 +1187,7 @@ class VersionSet {
   // Mark the specified log number as deleted
   // REQUIRED: this is only called during single-threaded recovery or repair, or
   // from ::LogAndApply where the global mutex is held.
-  void MarkMinLogNumberToKeep2PC(uint64_t number);
+  void MarkMinLogNumberToKeep(uint64_t number);
 
   // Return the log file number for the log file that is currently
   // being compacted, or zero if there is no such log file.
@@ -1196,10 +1196,12 @@ class VersionSet {
   // Returns the minimum log number which still has data not flushed to any SST
   // file.
   // In non-2PC mode, all the log numbers smaller than this number can be safely
-  // deleted.
+  // deleted, although we still use `min_log_number_to_keep_` to determine when
+  // to delete a WAL file.
   uint64_t MinLogNumberWithUnflushedData() const {
     return PreComputeMinLogNumberWithUnflushedData(nullptr);
   }
+
   // Returns the minimum log number which still has data not flushed to any SST
   // file.
   // Empty column families' log number is considered to be
@@ -1297,6 +1299,10 @@ class VersionSet {
                         uint64_t min_pending_output);
 
   ColumnFamilySet* GetColumnFamilySet() { return column_family_set_.get(); }
+  RefedColumnFamilySet GetRefedColumnFamilySet() {
+    return RefedColumnFamilySet(GetColumnFamilySet());
+  }
+
   const FileOptions& file_options() { return file_options_; }
   void ChangeFileOptions(const MutableDBOptions& new_options) {
     file_options_.writable_file_max_buffer_size =
@@ -1399,9 +1405,8 @@ class VersionSet {
   const ImmutableDBOptions* const db_options_;
   std::atomic<uint64_t> next_file_number_;
   // Any WAL number smaller than this should be ignored during recovery,
-  // and is qualified for being deleted in 2PC mode. In non-2PC mode, this
-  // number is ignored.
-  std::atomic<uint64_t> min_log_number_to_keep_2pc_ = {0};
+  // and is qualified for being deleted.
+  std::atomic<uint64_t> min_log_number_to_keep_ = {0};
   uint64_t manifest_file_number_;
   uint64_t options_file_number_;
   uint64_t options_file_size_;

db/version_set_test.cc

@@ -3424,6 +3424,7 @@ TEST_F(VersionSetTestMissingFiles, NoFileMissing) {
 }
 
 TEST_F(VersionSetTestMissingFiles, MinLogNumberToKeep2PC) {
+  db_options_.allow_2pc = true;
   NewDB();
 
   SstInfo sst(100, kDefaultColumnFamilyName, "a");
@@ -3435,12 +3436,12 @@ TEST_F(VersionSetTestMissingFiles, MinLogNumberToKeep2PC) {
   edit.AddFile(0, file_metas[0]);
   edit.SetMinLogNumberToKeep(kMinWalNumberToKeep2PC);
   ASSERT_OK(LogAndApplyToDefaultCF(edit));
-  ASSERT_EQ(versions_->min_log_number_to_keep_2pc(), kMinWalNumberToKeep2PC);
+  ASSERT_EQ(versions_->min_log_number_to_keep(), kMinWalNumberToKeep2PC);
 
   for (int i = 0; i < 3; i++) {
     CreateNewManifest();
     ReopenDB();
-    ASSERT_EQ(versions_->min_log_number_to_keep_2pc(), kMinWalNumberToKeep2PC);
+    ASSERT_EQ(versions_->min_log_number_to_keep(), kMinWalNumberToKeep2PC);
   }
 }
 

env/env_posix.cc

@@ -166,7 +166,7 @@ class PosixClock : public SystemClock {
     defined(OS_AIX) || (defined(__MACH__) && defined(__MAC_10_12))
     struct timespec ts;
     clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts);
-    return static_cast<uint64_t>(ts.tv_sec) * 1000000000;
+    return (static_cast<uint64_t>(ts.tv_sec) * 1000000000 + ts.tv_nsec) / 1000;
 #endif
     return 0;
   }

env/fs_posix.cc

@@ -325,14 +325,7 @@ class PosixFileSystem : public FileSystem {
     SetFD_CLOEXEC(fd, &options);
 
     if (options.use_mmap_writes) {
-      if (!checkedDiskForMmap_) {
-        // this will be executed once in the program's lifetime.
-        // do not use mmapWrite on non ext-3/xfs/tmpfs systems.
-        if (!SupportsFastAllocate(fname)) {
-          forceMmapOff_ = true;
-        }
-        checkedDiskForMmap_ = true;
-      }
+      MaybeForceDisableMmap(fd);
     }
     if (options.use_mmap_writes && !forceMmapOff_) {
       result->reset(new PosixMmapFile(fname, fd, page_size_, options));
@@ -431,14 +424,7 @@ class PosixFileSystem : public FileSystem {
     }
 
     if (options.use_mmap_writes) {
-      if (!checkedDiskForMmap_) {
-        // this will be executed once in the program's lifetime.
-        // do not use mmapWrite on non ext-3/xfs/tmpfs systems.
-        if (!SupportsFastAllocate(fname)) {
-          forceMmapOff_ = true;
-        }
-        checkedDiskForMmap_ = true;
-      }
+      MaybeForceDisableMmap(fd);
     }
     if (options.use_mmap_writes && !forceMmapOff_) {
       result->reset(new PosixMmapFile(fname, fd, page_size_, options));
@@ -753,8 +739,10 @@ class PosixFileSystem : public FileSystem {
                     const IOOptions& /*opts*/,
                     IODebugContext* /*dbg*/) override {
     if (link(src.c_str(), target.c_str()) != 0) {
-      if (errno == EXDEV) {
-        return IOStatus::NotSupported("No cross FS links allowed");
+      if (errno == EXDEV || errno == ENOTSUP) {
+        return IOStatus::NotSupported(errno == EXDEV
+                                          ? "No cross FS links allowed"
+                                          : "Links not supported by FS");
       }
       return IOError("while link file to " + target, src, errno);
     }
@@ -997,8 +985,7 @@ class PosixFileSystem : public FileSystem {
   }
 #endif
  private:
-  bool checkedDiskForMmap_;
-  bool forceMmapOff_;  // do we override Env options?
+  bool forceMmapOff_ = false;  // do we override Env options?
 
   // Returns true iff the named directory exists and is a directory.
   virtual bool DirExists(const std::string& dname) {
@@ -1009,10 +996,10 @@ class PosixFileSystem : public FileSystem {
     return false;  // stat() failed return false
   }
 
-  bool SupportsFastAllocate(const std::string& path) {
+  bool SupportsFastAllocate(int fd) {
 #ifdef ROCKSDB_FALLOCATE_PRESENT
     struct statfs s;
-    if (statfs(path.c_str(), &s)) {
+    if (fstatfs(fd, &s)) {
       return false;
     }
     switch (s.f_type) {
@@ -1026,11 +1013,26 @@ class PosixFileSystem : public FileSystem {
         return false;
     }
 #else
-    (void)path;
+    (void)fd;
     return false;
 #endif
   }
 
+  void MaybeForceDisableMmap(int fd) {
+    static std::once_flag s_check_disk_for_mmap_once;
+    assert(this == FileSystem::Default().get());
+    std::call_once(
+        s_check_disk_for_mmap_once,
+        [this](int fdesc) {
+          // this will be executed once in the program's lifetime.
+          // do not use mmapWrite on non ext-3/xfs/tmpfs systems.
+          if (!SupportsFastAllocate(fdesc)) {
+            forceMmapOff_ = true;
+          }
+        },
+        fd);
+  }
+
 #ifdef ROCKSDB_IOURING_PRESENT
   bool IsIOUringEnabled() {
     if (RocksDbIOUringEnable && RocksDbIOUringEnable()) {
@@ -1094,8 +1096,7 @@ size_t PosixFileSystem::GetLogicalBlockSizeForWriteIfNeeded(
 }
 
 PosixFileSystem::PosixFileSystem()
-    : checkedDiskForMmap_(false),
-      forceMmapOff_(false),
+    : forceMmapOff_(false),
       page_size_(getpagesize()),
       allow_non_owner_access_(true) {
 #if defined(ROCKSDB_IOURING_PRESENT)

file/writable_file_writer.h

@@ -160,7 +160,9 @@ class WritableFileWriter {
   bool perform_data_verification_;
   uint32_t buffered_data_crc32c_checksum_;
   bool buffered_data_with_checksum_;
+#ifndef ROCKSDB_LITE
   Temperature temperature_;
+#endif  // ROCKSDB_LITE
 
  public:
   WritableFileWriter(
@@ -191,8 +193,10 @@ class WritableFileWriter {
         checksum_finalized_(false),
         perform_data_verification_(perform_data_verification),
         buffered_data_crc32c_checksum_(0),
-        buffered_data_with_checksum_(buffered_data_with_checksum),
-        temperature_(options.temperature) {
+        buffered_data_with_checksum_(buffered_data_with_checksum) {
+#ifndef ROCKSDB_LITE
+    temperature_ = options.temperature;
+#endif  // ROCKSDB_LITE
     assert(!use_direct_io() || max_buffer_size_ > 0);
     TEST_SYNC_POINT_CALLBACK("WritableFileWriter::WritableFileWriter:0",
                              reinterpret_cast<void*>(max_buffer_size_));

include/rocksdb/db.h

@@ -780,7 +780,7 @@ class DB {
   // snapshot is no longer needed.
   //
   // nullptr will be returned if the DB fails to take a snapshot or does
-  // not support snapshot.
+  // not support snapshot (eg: inplace_update_support enabled).
   virtual const Snapshot* GetSnapshot() = 0;
 
   // Release a previously acquired snapshot.  The caller must not

include/rocksdb/filter_policy.h

@@ -90,6 +90,19 @@ class FilterPolicy : public Customizable {
   virtual ~FilterPolicy();
   static const char* Type() { return "FilterPolicy"; }
 
+  // The name used for identifying whether a filter on disk is readable
+  // by this FilterPolicy. If this FilterPolicy is part of a family that
+  // can read each others filters, such as built-in BloomFilterPolcy and
+  // RibbonFilterPolicy, the CompatibilityName is a shared family name,
+  // while kinds of filters in the family can have distinct Customizable
+  // Names. This function is pure virtual so that wrappers around built-in
+  // policies are prompted to defer to CompatibilityName() of the wrapped
+  // policy, which is important for compatibility.
+  //
+  // For custom filter policies that are not part of a read-compatible
+  // family (rare), implementations may return Name().
+  virtual const char* CompatibilityName() const = 0;
+
   // Creates a new FilterPolicy based on the input value string and returns the
   // result The value might be an ID, and ID with properties, or an old-style
   // policy string.

include/rocksdb/version.h

@@ -9,9 +9,9 @@
 
 #include "rocksdb/rocksdb_namespace.h"
 
-#define ROCKSDB_MAJOR 6
-#define ROCKSDB_MINOR 29
-#define ROCKSDB_PATCH 0
+#define ROCKSDB_MAJOR 7
+#define ROCKSDB_MINOR 0
+#define ROCKSDB_PATCH 4
 
 // Do not use these. We made the mistake of declaring macros starting with
 // double underscore. Now we have to live with our choice. We'll deprecate these

java/rocksjni/options.cc

@@ -4260,9 +4260,10 @@ void Java_org_rocksdb_ColumnFamilyOptions_setSstPartitionerFactory(
     JNIEnv*, jobject, jlong jhandle, jlong factory_handle) {
   auto* options =
       reinterpret_cast<ROCKSDB_NAMESPACE::ColumnFamilyOptions*>(jhandle);
-  auto* factory = reinterpret_cast<ROCKSDB_NAMESPACE::SstPartitionerFactory*>(
+  auto factory = reinterpret_cast<
+      std::shared_ptr<ROCKSDB_NAMESPACE::SstPartitionerFactory>*>(
       factory_handle);
-  options->sst_partitioner_factory.reset(factory);
+  options->sst_partitioner_factory = *factory;
 }
 
 /*

java/src/main/java/org/rocksdb/NativeLibraryLoader.java

@@ -18,7 +18,11 @@ public class NativeLibraryLoader {
 
   private static final String sharedLibraryName = Environment.getSharedLibraryName("rocksdb");
   private static final String jniLibraryName = Environment.getJniLibraryName("rocksdb");
+  private static final /* @Nullable */ String fallbackJniLibraryName =
+      Environment.getFallbackJniLibraryName("rocksdb");
   private static final String jniLibraryFileName = Environment.getJniLibraryFileName("rocksdb");
+  private static final /* @Nullable */ String fallbackJniLibraryFileName =
+      Environment.getFallbackJniLibraryFileName("rocksdb");
   private static final String tempFilePrefix = "librocksdbjni";
   private static final String tempFileSuffix = Environment.getJniLibraryExtension();
 
@@ -49,14 +53,33 @@ public class NativeLibraryLoader {
    */
   public synchronized void loadLibrary(final String tmpDir) throws IOException {
     try {
-        System.loadLibrary(sharedLibraryName);
-    } catch(final UnsatisfiedLinkError ule1) {
+      // try dynamic library
+      System.loadLibrary(sharedLibraryName);
+      return;
+    } catch (final UnsatisfiedLinkError ule) {
+      // ignore - try from static library
+    }
+
+    try {
+      // try static library
+      System.loadLibrary(jniLibraryName);
+      return;
+    } catch (final UnsatisfiedLinkError ule) {
+      // ignore - then try static library fallback or from jar
+    }
+
+    if (fallbackJniLibraryName != null) {
       try {
-        System.loadLibrary(jniLibraryName);
-      } catch(final UnsatisfiedLinkError ule2) {
-        loadLibraryFromJar(tmpDir);
+        // try static library fallback
+        System.loadLibrary(fallbackJniLibraryName);
+        return;
+      } catch (final UnsatisfiedLinkError ule) {
+        // ignore - then try from jar
       }
     }
+
+    // try jar
+    loadLibraryFromJar(tmpDir);
   }
 
   /**
@@ -83,43 +106,62 @@ public class NativeLibraryLoader {
 
   File loadLibraryFromJarToTemp(final String tmpDir)
           throws IOException {
-    final File temp;
-    if (tmpDir == null || tmpDir.isEmpty()) {
-      temp = File.createTempFile(tempFilePrefix, tempFileSuffix);
-    } else {
-      final File parentDir = new File(tmpDir);
-      if (!parentDir.exists()) {
-        throw new RuntimeException(
-            "Directory: " + parentDir.getAbsolutePath() + " does not exist!");
-      }
-      temp = new File(parentDir, jniLibraryFileName);
-      if (temp.exists() && !temp.delete()) {
-        throw new RuntimeException("File: " + temp.getAbsolutePath()
-            + " already exists and cannot be removed.");
-      }
-      if (!temp.createNewFile()) {
-        throw new RuntimeException("File: " + temp.getAbsolutePath()
-            + " could not be created.");
-      }
-    }
+    InputStream is = null;
+    try {
+      // attempt to look up the static library in the jar file
+      String libraryFileName = jniLibraryFileName;
+      is = getClass().getClassLoader().getResourceAsStream(libraryFileName);
 
-    if (!temp.exists()) {
-      throw new RuntimeException("File " + temp.getAbsolutePath() + " does not exist.");
-    } else {
-      temp.deleteOnExit();
-    }
-
-    // attempt to copy the library from the Jar file to the temp destination
-    try (final InputStream is = getClass().getClassLoader().
-      getResourceAsStream(jniLibraryFileName)) {
       if (is == null) {
-        throw new RuntimeException(jniLibraryFileName + " was not found inside JAR.");
+        // is there a fallback we can try
+        if (fallbackJniLibraryFileName == null) {
+          throw new RuntimeException(libraryFileName + " was not found inside JAR.");
+        }
+
+        // attempt to look up the fallback static library in the jar file
+        libraryFileName = fallbackJniLibraryFileName;
+        is = getClass().getClassLoader().getResourceAsStream(libraryFileName);
+        if (is == null) {
+          throw new RuntimeException(libraryFileName + " was not found inside JAR.");
+        }
+      }
+
+      // create a temporary file to copy the library to
+      final File temp;
+      if (tmpDir == null || tmpDir.isEmpty()) {
+        temp = File.createTempFile(tempFilePrefix, tempFileSuffix);
       } else {
-        Files.copy(is, temp.toPath(), StandardCopyOption.REPLACE_EXISTING);
+        final File parentDir = new File(tmpDir);
+        if (!parentDir.exists()) {
+          throw new RuntimeException(
+              "Directory: " + parentDir.getAbsolutePath() + " does not exist!");
+        }
+        temp = new File(parentDir, libraryFileName);
+        if (temp.exists() && !temp.delete()) {
+          throw new RuntimeException(
+              "File: " + temp.getAbsolutePath() + " already exists and cannot be removed.");
+        }
+        if (!temp.createNewFile()) {
+          throw new RuntimeException("File: " + temp.getAbsolutePath() + " could not be created.");
+        }
+      }
+      if (!temp.exists()) {
+        throw new RuntimeException("File " + temp.getAbsolutePath() + " does not exist.");
+      } else {
+        temp.deleteOnExit();
+      }
+
+      // copy the library from the Jar file to the temp destination
+      Files.copy(is, temp.toPath(), StandardCopyOption.REPLACE_EXISTING);
+
+      // return the temporary library file
+      return temp;
+
+    } finally {
+      if (is != null) {
+        is.close();
       }
     }
-
-    return temp;
   }
 
   /**

java/src/main/java/org/rocksdb/util/Environment.java

@@ -110,8 +110,14 @@ public class Environment {
         return String.format("%sjni-linux%s%s", name, arch, getLibcPostfix());
       }
     } else if (isMac()) {
-      if (isAarch64()) {
-        return String.format("%sjni-osx-%s", name, ARCH);
+      if (is64Bit()) {
+        final String arch;
+        if (isAarch64()) {
+          arch = "arm64";
+        } else {
+          arch = "x86_64";
+        }
+        return String.format("%sjni-osx-%s", name, arch);
       } else {
         return String.format("%sjni-osx", name);
       }
@@ -131,10 +137,25 @@ public class Environment {
     throw new UnsupportedOperationException(String.format("Cannot determine JNI library name for ARCH='%s' OS='%s' name='%s'", ARCH, OS, name));
   }
 
+  public static /*@Nullable*/ String getFallbackJniLibraryName(final String name) {
+    if (isMac() && is64Bit()) {
+      return String.format("%sjni-osx", name);
+    }
+    return null;
+  }
+
   public static String getJniLibraryFileName(final String name) {
     return appendLibOsSuffix("lib" + getJniLibraryName(name), false);
   }
 
+  public static /*@Nullable*/ String getFallbackJniLibraryFileName(final String name) {
+    final String fallbackJniLibraryName = getFallbackJniLibraryName(name);
+    if (fallbackJniLibraryName == null) {
+      return null;
+    }
+    return appendLibOsSuffix("lib" + fallbackJniLibraryName, false);
+  }
+
   private static String appendLibOsSuffix(final String libraryFileName, final boolean shared) {
     if (isUnix() || isAix() || isSolaris() || isFreeBSD() || isOpenBSD()) {
       return libraryFileName + ".so";

java/src/test/java/org/rocksdb/SstPartitionerTest.java

@@ -5,6 +5,7 @@
 
 package org.rocksdb;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.util.List;
@@ -21,7 +22,7 @@ public class SstPartitionerTest {
   @Rule public TemporaryFolder dbFolder = new TemporaryFolder();
 
   @Test
-  public void sstFixedPrefix() throws InterruptedException, RocksDBException {
+  public void sstFixedPrefix() throws RocksDBException {
     try (SstPartitionerFixedPrefixFactory factory = new SstPartitionerFixedPrefixFactory(4);
          final Options opt =
              new Options().setCreateIfMissing(true).setSstPartitionerFactory(factory);
@@ -31,7 +32,8 @@ public class SstPartitionerTest {
       db.put("bbbb1".getBytes(), "B".getBytes());
       db.flush(new FlushOptions());
 
-      db.put("aaaa1".getBytes(), "A2".getBytes());
+      db.put("aaaa0".getBytes(), "A2".getBytes());
+      db.put("aaaa2".getBytes(), "A2".getBytes());
       db.flush(new FlushOptions());
 
       db.compactRange();
@@ -40,4 +42,31 @@ public class SstPartitionerTest {
       assertThat(metadata.size()).isEqualTo(2);
     }
   }
+
+  @Test
+  public void sstFixedPrefixFamily() throws RocksDBException {
+    final byte[] cfName = "new_cf".getBytes(UTF_8);
+    final ColumnFamilyDescriptor cfDescriptor = new ColumnFamilyDescriptor(cfName,
+        new ColumnFamilyOptions().setSstPartitionerFactory(
+            new SstPartitionerFixedPrefixFactory(4)));
+
+    try (final Options opt = new Options().setCreateIfMissing(true);
+         final RocksDB db = RocksDB.open(opt, dbFolder.getRoot().getAbsolutePath())) {
+      final ColumnFamilyHandle columnFamilyHandle = db.createColumnFamily(cfDescriptor);
+
+      // writing (long)100 under key
+      db.put(columnFamilyHandle, "aaaa1".getBytes(), "A".getBytes());
+      db.put(columnFamilyHandle, "bbbb1".getBytes(), "B".getBytes());
+      db.flush(new FlushOptions(), columnFamilyHandle);
+
+      db.put(columnFamilyHandle, "aaaa0".getBytes(), "A2".getBytes());
+      db.put(columnFamilyHandle, "aaaa2".getBytes(), "A2".getBytes());
+      db.flush(new FlushOptions(), columnFamilyHandle);
+
+      db.compactRange(columnFamilyHandle);
+
+      List<LiveFileMetaData> metadata = db.getLiveFilesMetaData();
+      assertThat(metadata.size()).isEqualTo(2);
+    }
+  }
 }

java/src/test/java/org/rocksdb/util/EnvironmentTest.java

@@ -9,7 +9,6 @@ import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -37,18 +36,21 @@ public class EnvironmentTest {
         isEqualTo(".jnilib");
     assertThat(Environment.getJniLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni-osx.jnilib");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni.dylib");
   }
 
   @Test
-  public void mac64() {
-    setEnvironmentClassFields("mac", "x86-64");
+  public void mac64_x86_64() {
+    setEnvironmentClassFields("mac", "x86_64");
     assertThat(Environment.isWindows()).isFalse();
     assertThat(Environment.getJniLibraryExtension()).
         isEqualTo(".jnilib");
-    assertThat(Environment.getJniLibraryFileName("rocksdb")).
-        isEqualTo("librocksdbjni-osx.jnilib");
+    assertThat(Environment.getJniLibraryFileName("rocksdb"))
+        .isEqualTo("librocksdbjni-osx-x86_64.jnilib");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb"))
+        .isEqualTo("librocksdbjni-osx.jnilib");
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni.dylib");
   }
@@ -59,7 +61,9 @@ public class EnvironmentTest {
     assertThat(Environment.isWindows()).isFalse();
     assertThat(Environment.getJniLibraryExtension()).isEqualTo(".jnilib");
     assertThat(Environment.getJniLibraryFileName("rocksdb"))
-        .isEqualTo("librocksdbjni-osx-aarch64.jnilib");
+        .isEqualTo("librocksdbjni-osx-arm64.jnilib");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb"))
+        .isEqualTo("librocksdbjni-osx.jnilib");
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).isEqualTo("librocksdbjni.dylib");
   }
 
@@ -73,6 +77,7 @@ public class EnvironmentTest {
         isEqualTo(".so");
     assertThat(Environment.getJniLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni-linux32.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni.so");
     // Linux musl-libc (Alpine)
@@ -103,7 +108,8 @@ public class EnvironmentTest {
     assertThat(Environment.isWindows()).isFalse();
     assertThat(Environment.getJniLibraryExtension()).
         isEqualTo(".so");
-    Environment.getJniLibraryFileName("rocksdb");
+    assertThat(Environment.getJniLibraryFileName("rocksdb")).isEqualTo("blah");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
   }
 
   @Test
@@ -115,6 +121,7 @@ public class EnvironmentTest {
         isEqualTo(".so");
     assertThat(Environment.getJniLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni-linux64.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni.so");
     // Linux musl-libc (Alpine)
@@ -124,6 +131,7 @@ public class EnvironmentTest {
         isEqualTo(".so");
     assertThat(Environment.getJniLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni-linux64-musl.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni.so");
     // UNIX
@@ -134,6 +142,7 @@ public class EnvironmentTest {
         isEqualTo(".so");
     assertThat(Environment.getJniLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni-linux64.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni.so");
     // AIX
@@ -143,6 +152,7 @@ public class EnvironmentTest {
         isEqualTo(".so");
     assertThat(Environment.getJniLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni-aix64.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
         isEqualTo("librocksdbjni.so");
   }
@@ -161,6 +171,7 @@ public class EnvironmentTest {
       isEqualTo(".dll");
     assertThat(Environment.getJniLibraryFileName("rocksdb")).
       isEqualTo("librocksdbjni-win64.dll");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).
       isEqualTo("librocksdbjni.dll");
   }
@@ -177,6 +188,7 @@ public class EnvironmentTest {
     assertThat(Environment.getJniLibraryName("rocksdb")).isEqualTo("rocksdbjni-linux-ppc64le");
     assertThat(Environment.getJniLibraryFileName("rocksdb"))
         .isEqualTo("librocksdbjni-linux-ppc64le.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).isEqualTo("librocksdbjni.so");
     // Linux musl-libc (Alpine)
     setEnvironmentClassField(MUSL_LIBC_FIELD_NAME, true);
@@ -189,6 +201,7 @@ public class EnvironmentTest {
     assertThat(Environment.getJniLibraryName("rocksdb")).isEqualTo("rocksdbjni-linux-ppc64le-musl");
     assertThat(Environment.getJniLibraryFileName("rocksdb"))
         .isEqualTo("librocksdbjni-linux-ppc64le-musl.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).isEqualTo("librocksdbjni.so");
     setEnvironmentClassField(MUSL_LIBC_FIELD_NAME, false);
   }
@@ -205,6 +218,7 @@ public class EnvironmentTest {
     assertThat(Environment.getJniLibraryName("rocksdb")).isEqualTo("rocksdbjni-linux-aarch64");
     assertThat(Environment.getJniLibraryFileName("rocksdb"))
         .isEqualTo("librocksdbjni-linux-aarch64.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).isEqualTo("librocksdbjni.so");
     // Linux musl-libc (Alpine)
     setEnvironmentClassField(MUSL_LIBC_FIELD_NAME, true);
@@ -217,6 +231,7 @@ public class EnvironmentTest {
     assertThat(Environment.getJniLibraryName("rocksdb")).isEqualTo("rocksdbjni-linux-aarch64-musl");
     assertThat(Environment.getJniLibraryFileName("rocksdb"))
         .isEqualTo("librocksdbjni-linux-aarch64-musl.so");
+    assertThat(Environment.getFallbackJniLibraryFileName("rocksdb")).isNull();
     assertThat(Environment.getSharedLibraryFileName("rocksdb")).isEqualTo("librocksdbjni.so");
     setEnvironmentClassField(MUSL_LIBC_FIELD_NAME, false);
   }

monitoring/instrumented_mutex.h

@@ -51,6 +51,14 @@ class InstrumentedMutex {
   int stats_code_;
 };
 
+class ALIGN_AS(CACHE_LINE_SIZE) CacheAlignedInstrumentedMutex
+    : public InstrumentedMutex {
+  using InstrumentedMutex::InstrumentedMutex;
+  char padding[(CACHE_LINE_SIZE - sizeof(InstrumentedMutex) % CACHE_LINE_SIZE) %
+               CACHE_LINE_SIZE] ROCKSDB_FIELD_UNUSED;
+};
+static_assert(sizeof(CacheAlignedInstrumentedMutex) % CACHE_LINE_SIZE == 0);
+
 // RAII wrapper for InstrumentedMutex
 class InstrumentedMutexLock {
  public:

options/customizable_test.cc

@@ -1487,6 +1487,7 @@ class MockFilterPolicy : public FilterPolicy {
  public:
   static const char* kClassName() { return "MockFilterPolicy"; }
   const char* Name() const override { return kClassName(); }
+  const char* CompatibilityName() const override { return Name(); }
   FilterBitsBuilder* GetBuilderWithContext(
       const FilterBuildingContext&) const override {
     return nullptr;

port/win/env_win.cc

@@ -9,6 +9,8 @@
 
 #if defined(OS_WIN)
 
+#include "port/win/env_win.h"
+
 #include <direct.h>  // _rmdir, _mkdir, _getcwd
 #include <errno.h>
 #include <io.h>   // _access
@@ -17,6 +19,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <windows.h>
+#include <winioctl.h>
 
 #include <algorithm>
 #include <ctime>
@@ -27,7 +30,6 @@
 #include "monitoring/thread_status_util.h"
 #include "port/port.h"
 #include "port/port_dirent.h"
-#include "port/win/env_win.h"
 #include "port/win/io_win.h"
 #include "port/win/win_logger.h"
 #include "rocksdb/env.h"

table/block_based/block_based_table_builder.cc

@@ -1605,7 +1605,7 @@ void BlockBasedTableBuilder::WriteFilterBlock(
                 ? BlockBasedTable::kPartitionedFilterBlockPrefix
                 : BlockBasedTable::kFullFilterBlockPrefix;
     }
-    key.append(rep_->table_options.filter_policy->Name());
+    key.append(rep_->table_options.filter_policy->CompatibilityName());
     meta_index_builder->Add(key, filter_block_handle);
   }
 }

table/block_based/block_based_table_reader.cc

@@ -12,6 +12,7 @@
 #include <array>
 #include <limits>
 #include <string>
+#include <unordered_set>
 #include <utility>
 #include <vector>
 
@@ -50,6 +51,7 @@
 #include "table/block_based/block_prefix_index.h"
 #include "table/block_based/block_type.h"
 #include "table/block_based/filter_block.h"
+#include "table/block_based/filter_policy_internal.h"
 #include "table/block_based/full_filter_block.h"
 #include "table/block_based/hash_index_reader.h"
 #include "table/block_based/partitioned_filter_block.h"
@@ -899,33 +901,59 @@ Status BlockBasedTable::PrefetchIndexAndFilterBlocks(
     const BlockBasedTableOptions& table_options, const int level,
     size_t file_size, size_t max_file_size_for_l0_meta_pin,
     BlockCacheLookupContext* lookup_context) {
-  Status s;
-
   // Find filter handle and filter type
   if (rep_->filter_policy) {
-    for (auto filter_type :
-         {Rep::FilterType::kFullFilter, Rep::FilterType::kPartitionedFilter,
-          Rep::FilterType::kBlockFilter}) {
-      std::string prefix;
-      switch (filter_type) {
-        case Rep::FilterType::kFullFilter:
-          prefix = kFullFilterBlockPrefix;
+    auto name = rep_->filter_policy->CompatibilityName();
+    bool builtin_compatible =
+        strcmp(name, BuiltinFilterPolicy::kCompatibilityName()) == 0;
+
+    for (const auto& [filter_type, prefix] :
+         {std::make_pair(Rep::FilterType::kFullFilter, kFullFilterBlockPrefix),
+          std::make_pair(Rep::FilterType::kPartitionedFilter,
+                         kPartitionedFilterBlockPrefix),
+          std::make_pair(Rep::FilterType::kBlockFilter, kFilterBlockPrefix)}) {
+      if (builtin_compatible) {
+        // This code is only here to deal with a hiccup in early 7.0.x where
+        // there was an unintentional name change in the SST files metadata.
+        // It should be OK to remove this in the future (late 2022) and just
+        // have the 'else' code.
+        // NOTE: the test:: names below are likely not needed but included
+        // out of caution
+        static const std::unordered_set<std::string> kBuiltinNameAndAliases = {
+            BuiltinFilterPolicy::kCompatibilityName(),
+            test::LegacyBloomFilterPolicy::kClassName(),
+            test::FastLocalBloomFilterPolicy::kClassName(),
+            test::Standard128RibbonFilterPolicy::kClassName(),
+            DeprecatedBlockBasedBloomFilterPolicy::kClassName(),
+            BloomFilterPolicy::kClassName(),
+            RibbonFilterPolicy::kClassName(),
+        };
+
+        // For efficiency, do a prefix seek and see if the first match is
+        // good.
+        meta_iter->Seek(prefix);
+        if (meta_iter->status().ok() && meta_iter->Valid()) {
+          Slice key = meta_iter->key();
+          if (key.starts_with(prefix)) {
+            key.remove_prefix(prefix.size());
+            if (kBuiltinNameAndAliases.find(key.ToString()) !=
+                kBuiltinNameAndAliases.end()) {
+              Slice v = meta_iter->value();
+              Status s = rep_->filter_handle.DecodeFrom(&v);
+              if (s.ok()) {
+                rep_->filter_type = filter_type;
+                break;
+              }
+            }
+          }
+        }
+      } else {
+        std::string filter_block_key = prefix + name;
+        if (FindMetaBlock(meta_iter, filter_block_key, &rep_->filter_handle)
+                .ok()) {
+          rep_->filter_type = filter_type;
           break;
-        case Rep::FilterType::kPartitionedFilter:
-          prefix = kPartitionedFilterBlockPrefix;
-          break;
-        case Rep::FilterType::kBlockFilter:
-          prefix = kFilterBlockPrefix;
-          break;
-        default:
-          assert(0);
-      }
-      std::string filter_block_key = prefix;
-      filter_block_key.append(rep_->filter_policy->Name());
-      if (FindMetaBlock(meta_iter, filter_block_key, &rep_->filter_handle)
-              .ok()) {
-        rep_->filter_type = filter_type;
-        break;
+        }
       }
     }
   }
@@ -934,8 +962,8 @@ Status BlockBasedTable::PrefetchIndexAndFilterBlocks(
          rep_->index_type == BlockBasedTableOptions::kTwoLevelIndexSearch);
 
   // Find compression dictionary handle
-  s = FindOptionalMetaBlock(meta_iter, kCompressionDictBlockName,
-                            &rep_->compression_dict_handle);
+  Status s = FindOptionalMetaBlock(meta_iter, kCompressionDictBlockName,
+                                   &rep_->compression_dict_handle);
   if (!s.ok()) {
     return s;
   }
@@ -1439,9 +1467,10 @@ template <typename TBlocklike>
 Status BlockBasedTable::MaybeReadBlockAndLoadToCache(
     FilePrefetchBuffer* prefetch_buffer, const ReadOptions& ro,
     const BlockHandle& handle, const UncompressionDict& uncompression_dict,
-    const bool wait, CachableEntry<TBlocklike>* block_entry,
-    BlockType block_type, GetContext* get_context,
-    BlockCacheLookupContext* lookup_context, BlockContents* contents) const {
+    const bool wait, const bool for_compaction,
+    CachableEntry<TBlocklike>* block_entry, BlockType block_type,
+    GetContext* get_context, BlockCacheLookupContext* lookup_context,
+    BlockContents* contents) const {
   assert(block_entry != nullptr);
   const bool no_io = (ro.read_tier == kBlockCacheTier);
   Cache* block_cache = rep_->table_options.block_cache.get();
@@ -1494,7 +1523,9 @@ Status BlockBasedTable::MaybeReadBlockAndLoadToCache(
       CompressionType raw_block_comp_type;
       BlockContents raw_block_contents;
       if (!contents) {
-        StopWatch sw(rep_->ioptions.clock, statistics, READ_BLOCK_GET_MICROS);
+        Histograms histogram = for_compaction ? READ_BLOCK_COMPACTION_MICROS
+                                              : READ_BLOCK_GET_MICROS;
+        StopWatch sw(rep_->ioptions.clock, statistics, histogram);
         BlockFetcher block_fetcher(
             rep_->file.get(), prefetch_buffer, rep_->footer, ro, handle,
             &raw_block_contents, rep_->ioptions, do_uncompress,
@@ -1852,8 +1883,9 @@ void BlockBasedTable::RetrieveMultipleBlocks(
         // avoid looking up the block cache
         s = MaybeReadBlockAndLoadToCache(
             nullptr, options, handle, uncompression_dict, /*wait=*/true,
-            block_entry, BlockType::kData, mget_iter->get_context,
-            &lookup_data_block_context, &raw_block_contents);
+            /*for_compaction=*/false, block_entry, BlockType::kData,
+            mget_iter->get_context, &lookup_data_block_context,
+            &raw_block_contents);
 
         // block_entry value could be null if no block cache is present, i.e
         // BlockBasedTableOptions::no_block_cache is true and no compressed
@@ -1907,7 +1939,7 @@ Status BlockBasedTable::RetrieveBlock(
   if (use_cache) {
     s = MaybeReadBlockAndLoadToCache(
         prefetch_buffer, ro, handle, uncompression_dict, wait_for_cache,
-        block_entry, block_type, get_context, lookup_context,
+        for_compaction, block_entry, block_type, get_context, lookup_context,
         /*contents=*/nullptr);
 
     if (!s.ok()) {
@@ -1936,8 +1968,9 @@ Status BlockBasedTable::RetrieveBlock(
   std::unique_ptr<TBlocklike> block;
 
   {
-    StopWatch sw(rep_->ioptions.clock, rep_->ioptions.stats,
-                 READ_BLOCK_GET_MICROS);
+    Histograms histogram =
+        for_compaction ? READ_BLOCK_COMPACTION_MICROS : READ_BLOCK_GET_MICROS;
+    StopWatch sw(rep_->ioptions.clock, rep_->ioptions.stats, histogram);
     s = ReadBlockFromFile(
         rep_->file.get(), prefetch_buffer, rep_->footer, ro, handle, &block,
         rep_->ioptions, do_uncompress, maybe_compressed, block_type,
@@ -3158,6 +3191,7 @@ Status BlockBasedTable::CreateIndexReader(
 uint64_t BlockBasedTable::ApproximateDataOffsetOf(
     const InternalIteratorBase<IndexValue>& index_iter,
     uint64_t data_size) const {
+  assert(index_iter.status().ok());
   if (index_iter.Valid()) {
     BlockHandle handle = index_iter.value().handle;
     return handle.offset();
@@ -3200,8 +3234,16 @@ uint64_t BlockBasedTable::ApproximateOffsetOf(const Slice& key,
   }
 
   index_iter->Seek(key);
+  uint64_t offset;
+  if (index_iter->status().ok()) {
+    offset = ApproximateDataOffsetOf(*index_iter, data_size);
+  } else {
+    // Split in half to avoid skewing one way or another,
+    // since we don't know whether we're operating on lower bound or
+    // upper bound.
+    return rep_->file_size / 2;
+  }
 
-  uint64_t offset = ApproximateDataOffsetOf(*index_iter, data_size);
   // Pro-rate file metadata (incl filters) size-proportionally across data
   // blocks.
   double size_ratio =
@@ -3217,7 +3259,9 @@ uint64_t BlockBasedTable::ApproximateSize(const Slice& start, const Slice& end,
   uint64_t data_size = GetApproximateDataSize();
   if (UNLIKELY(data_size == 0)) {
     // Hmm. Assume whole file is involved, since we have lower and upper
-    // bound.
+    // bound. This likely skews the estimate if we consider that this function
+    // is typically called with `[start, end]` fully contained in the file's
+    // key-range.
     return rep_->file_size;
   }
 
@@ -3235,9 +3279,24 @@ uint64_t BlockBasedTable::ApproximateSize(const Slice& start, const Slice& end,
   }
 
   index_iter->Seek(start);
-  uint64_t start_offset = ApproximateDataOffsetOf(*index_iter, data_size);
+  uint64_t start_offset;
+  if (index_iter->status().ok()) {
+    start_offset = ApproximateDataOffsetOf(*index_iter, data_size);
+  } else {
+    // Assume file is involved from the start. This likely skews the estimate
+    // but is consistent with the above error handling.
+    start_offset = 0;
+  }
+
   index_iter->Seek(end);
-  uint64_t end_offset = ApproximateDataOffsetOf(*index_iter, data_size);
+  uint64_t end_offset;
+  if (index_iter->status().ok()) {
+    end_offset = ApproximateDataOffsetOf(*index_iter, data_size);
+  } else {
+    // Assume file is involved until the end. This likely skews the estimate
+    // but is consistent with the above error handling.
+    end_offset = data_size;
+  }
 
   assert(end_offset >= start_offset);
   // Pro-rate file metadata (incl filters) size-proportionally across data

table/block_based/block_based_table_reader.h

@@ -343,9 +343,10 @@ class BlockBasedTable : public TableReader {
   Status MaybeReadBlockAndLoadToCache(
       FilePrefetchBuffer* prefetch_buffer, const ReadOptions& ro,
       const BlockHandle& handle, const UncompressionDict& uncompression_dict,
-      const bool wait, CachableEntry<TBlocklike>* block_entry,
-      BlockType block_type, GetContext* get_context,
-      BlockCacheLookupContext* lookup_context, BlockContents* contents) const;
+      const bool wait, const bool for_compaction,
+      CachableEntry<TBlocklike>* block_entry, BlockType block_type,
+      GetContext* get_context, BlockCacheLookupContext* lookup_context,
+      BlockContents* contents) const;
 
   // Similar to the above, with one crucial difference: it will retrieve the
   // block from the file even if there are no caches configured (assuming the

table/block_based/filter_policy.cc

@@ -1325,6 +1325,16 @@ bool BuiltinFilterPolicy::IsInstanceOf(const std::string& name) const {
   }
 }
 
+static const char* kBuiltinFilterMetadataName = "rocksdb.BuiltinBloomFilter";
+
+const char* BuiltinFilterPolicy::kCompatibilityName() {
+  return kBuiltinFilterMetadataName;
+}
+
+const char* BuiltinFilterPolicy::CompatibilityName() const {
+  return kBuiltinFilterMetadataName;
+}
+
 BloomLikeFilterPolicy::BloomLikeFilterPolicy(double bits_per_key)
     : warned_(false), aggregate_rounding_balance_(0) {
   // Sanitize bits_per_key
@@ -1372,7 +1382,7 @@ bool BloomLikeFilterPolicy::IsInstanceOf(const std::string& name) const {
 }
 
 const char* ReadOnlyBuiltinFilterPolicy::kClassName() {
-  return "rocksdb.BuiltinBloomFilter";
+  return kBuiltinFilterMetadataName;
 }
 
 const char* DeprecatedBlockBasedBloomFilterPolicy::kClassName() {

table/block_based/filter_policy_internal.h

@@ -135,6 +135,9 @@ class BuiltinFilterPolicy : public FilterPolicy {
   FilterBitsReader* GetFilterBitsReader(const Slice& contents) const override;
   static const char* kClassName();
   bool IsInstanceOf(const std::string& id) const override;
+  // All variants of BuiltinFilterPolicy can read each others filters.
+  const char* CompatibilityName() const override;
+  static const char* kCompatibilityName();
 
  public:  // new
   // An internal function for the implementation of

table/block_based/full_filter_block_test.cc

@@ -84,6 +84,7 @@ class TestFilterBitsReader : public FilterBitsReader {
 class TestHashFilter : public FilterPolicy {
  public:
   const char* Name() const override { return "TestHashFilter"; }
+  const char* CompatibilityName() const override { return Name(); }
 
   FilterBitsBuilder* GetBuilderWithContext(
       const FilterBuildingContext&) const override {

table/block_based/partitioned_filter_block.cc

@@ -519,8 +519,8 @@ Status PartitionedFilterBlockReader::CacheDependencies(const ReadOptions& ro,
     // filter blocks
     s = table()->MaybeReadBlockAndLoadToCache(
         prefetch_buffer.get(), ro, handle, UncompressionDict::GetEmptyDict(),
-        /* wait */ true, &block, BlockType::kFilter, nullptr /* get_context */,
-        &lookup_context, nullptr /* contents */);
+        /* wait */ true, /* for_compaction */ false, &block, BlockType::kFilter,
+        nullptr /* get_context */, &lookup_context, nullptr /* contents */);
     if (!s.ok()) {
       return s;
     }

table/block_based/partitioned_index_reader.cc

@@ -180,8 +180,8 @@ Status PartitionIndexReader::CacheDependencies(const ReadOptions& ro,
     // filter blocks
     Status s = table()->MaybeReadBlockAndLoadToCache(
         prefetch_buffer.get(), ro, handle, UncompressionDict::GetEmptyDict(),
-        /*wait=*/true, &block, BlockType::kIndex, /*get_context=*/nullptr,
-        &lookup_context, /*contents=*/nullptr);
+        /*wait=*/true, /*for_compaction=*/false, &block, BlockType::kIndex,
+        /*get_context=*/nullptr, &lookup_context, /*contents=*/nullptr);
 
     if (!s.ok()) {
       return s;

util/compression.h

@@ -744,9 +744,6 @@ inline bool Zlib_Compress(const CompressionInfo& info,
     output_header_len = compression::PutDecompressedSizeInfo(
         output, static_cast<uint32_t>(length));
   }
-  // Resize output to be the plain data length.
-  // This may not be big enough if the compression actually expands data.
-  output->resize(output_header_len + length);
 
   // The memLevel parameter specifies how much memory should be allocated for
   // the internal compression state.
@@ -780,12 +777,17 @@ inline bool Zlib_Compress(const CompressionInfo& info,
     }
   }
 
+  // Get an upper bound on the compressed size.
+  size_t upper_bound =
+      deflateBound(&_stream, static_cast<unsigned long>(length));
+  output->resize(output_header_len + upper_bound);
+
   // Compress the input, and put compressed data in output.
   _stream.next_in = (Bytef*)input;
   _stream.avail_in = static_cast<unsigned int>(length);
 
   // Initialize the output size.
-  _stream.avail_out = static_cast<unsigned int>(length);
+  _stream.avail_out = static_cast<unsigned int>(upper_bound);
   _stream.next_out = reinterpret_cast<Bytef*>(&(*output)[output_header_len]);
 
   bool compressed = false;

util/math.h

@@ -92,18 +92,25 @@ inline int CountTrailingZeroBits(T v) {
 #endif
 }
 
-#if defined(_MSC_VER) && !defined(_M_X64)
+// Not all MSVC compile settings will use `BitsSetToOneFallback()`. We include
+// the following code at coarse granularity for simpler macros. It's important
+// to exclude at least so our non-MSVC unit test coverage tool doesn't see it.
+#ifdef _MSC_VER
+
 namespace detail {
+
 template <typename T>
 int BitsSetToOneFallback(T v) {
   const int kBits = static_cast<int>(sizeof(T)) * 8;
   static_assert((kBits & (kBits - 1)) == 0, "must be power of two bits");
   // we static_cast these bit patterns in order to truncate them to the correct
-  // size
+  // size. Warning C4309 dislikes this technique, so disable it here.
+#pragma warning(disable : 4309)
   v = static_cast<T>(v - ((v >> 1) & static_cast<T>(0x5555555555555555ull)));
   v = static_cast<T>((v & static_cast<T>(0x3333333333333333ull)) +
                      ((v >> 2) & static_cast<T>(0x3333333333333333ull)));
   v = static_cast<T>((v + (v >> 4)) & static_cast<T>(0x0F0F0F0F0F0F0F0Full));
+#pragma warning(default : 4309)
   for (int shift_bits = 8; shift_bits < kBits; shift_bits <<= 1) {
     v += static_cast<T>(v >> shift_bits);
   }
@@ -113,7 +120,8 @@ int BitsSetToOneFallback(T v) {
 }
 
 }  // namespace detail
-#endif
+
+#endif  // _MSC_VER
 
 // Number of bits set to 1. Also known as "population count".
 template <typename T>
@@ -126,21 +134,21 @@ inline int BitsSetToOne(T v) {
     constexpr auto mm = 8 * sizeof(uint32_t) - 1;
     // The bit mask is to neutralize sign extension on small signed types
     constexpr uint32_t m = (uint32_t{1} << ((8 * sizeof(T)) & mm)) - 1;
-#if defined(_M_X64) || defined(_M_IX86)
+#if defined(HAVE_SSE42) && (defined(_M_X64) || defined(_M_IX86))
     return static_cast<int>(__popcnt(static_cast<uint32_t>(v) & m));
 #else
     return static_cast<int>(detail::BitsSetToOneFallback(v) & m);
 #endif
   } else if (sizeof(T) == sizeof(uint32_t)) {
-#if defined(_M_X64) || defined(_M_IX86)
+#if defined(HAVE_SSE42) && (defined(_M_X64) || defined(_M_IX86))
     return static_cast<int>(__popcnt(static_cast<uint32_t>(v)));
 #else
     return detail::BitsSetToOneFallback(static_cast<uint32_t>(v));
 #endif
   } else {
-#ifdef _M_X64
+#if defined(HAVE_SSE42) && defined(_M_X64)
     return static_cast<int>(__popcnt64(static_cast<uint64_t>(v)));
-#elif defined(_M_IX86)
+#elif defined(HAVE_SSE42) && defined(_M_IX86)
     return static_cast<int>(
         __popcnt(static_cast<uint32_t>(static_cast<uint64_t>(v) >> 32) +
                  __popcnt(static_cast<uint32_t>(v))));

util/timer.h

@@ -48,36 +48,38 @@ class Timer {
   ~Timer() { Shutdown(); }
 
   // Add a new function to run.
-  // fn_name has to be identical, otherwise, the new one overrides the existing
-  // one, regardless if the function is pending removed (invalid) or not.
+  // fn_name has to be identical, otherwise it will fail to add and return false
   // start_after_us is the initial delay.
   // repeat_every_us is the interval between ending time of the last call and
   // starting time of the next call. For example, repeat_every_us = 2000 and
   // the function takes 1000us to run. If it starts at time [now]us, then it
   // finishes at [now]+1000us, 2nd run starting time will be at [now]+3000us.
   // repeat_every_us == 0 means do not repeat.
-  void Add(std::function<void()> fn,
-           const std::string& fn_name,
-           uint64_t start_after_us,
-           uint64_t repeat_every_us) {
-    std::unique_ptr<FunctionInfo> fn_info(new FunctionInfo(
-        std::move(fn), fn_name, clock_->NowMicros() + start_after_us,
-        repeat_every_us));
-    {
-      InstrumentedMutexLock l(&mutex_);
-      auto it = map_.find(fn_name);
-      if (it == map_.end()) {
-        heap_.push(fn_info.get());
-        map_.emplace(std::make_pair(fn_name, std::move(fn_info)));
-      } else {
-        // If it already exists, overriding it.
-        it->second->fn = std::move(fn_info->fn);
-        it->second->valid = true;
-        it->second->next_run_time_us = clock_->NowMicros() + start_after_us;
-        it->second->repeat_every_us = repeat_every_us;
-      }
+  bool Add(std::function<void()> fn, const std::string& fn_name,
+           uint64_t start_after_us, uint64_t repeat_every_us) {
+    auto fn_info = std::make_unique<FunctionInfo>(std::move(fn), fn_name, 0,
+                                                  repeat_every_us);
+    InstrumentedMutexLock l(&mutex_);
+    // Assign time within mutex to make sure the next_run_time is larger than
+    // the current running one
+    fn_info->next_run_time_us = clock_->NowMicros() + start_after_us;
+    // the new task start time should never before the current task executing
+    // time, as the executing task can only be running if it's next_run_time_us
+    // is due (<= clock_->NowMicros()).
+    if (executing_task_ &&
+        fn_info->next_run_time_us < heap_.top()->next_run_time_us) {
+      return false;
+    }
+    auto it = map_.find(fn_name);
+    if (it == map_.end()) {
+      heap_.push(fn_info.get());
+      map_.try_emplace(fn_name, std::move(fn_info));
+    } else {
+      // timer doesn't support duplicated function name
+      return false;
     }
     cond_var_.SignalAll();
+    return true;
   }
 
   void Cancel(const std::string& fn_name) {
@@ -116,7 +118,7 @@ class Timer {
     }
 
     running_ = true;
-    thread_.reset(new port::Thread(&Timer::Run, this));
+    thread_ = std::make_unique<port::Thread>(&Timer::Run, this);
     return true;
   }
 
@@ -140,8 +142,8 @@ class Timer {
 
   bool HasPendingTask() const {
     InstrumentedMutexLock l(&mutex_);
-    for (auto it = map_.begin(); it != map_.end(); it++) {
-      if (it->second->IsValid()) {
+    for (const auto& fn_info : map_) {
+      if (fn_info.second->IsValid()) {
         return true;
       }
     }
@@ -155,7 +157,7 @@ class Timer {
   // here to bump current time and trigger Timer. See timer_test for example.
   //
   // Note: only support one caller of this method.
-  void TEST_WaitForRun(std::function<void()> callback = nullptr) {
+  void TEST_WaitForRun(const std::function<void()>& callback = nullptr) {
     InstrumentedMutexLock l(&mutex_);
     // It act as a spin lock
     while (executing_task_ ||
@@ -177,8 +179,8 @@ class Timer {
   size_t TEST_GetPendingTaskNum() const {
     InstrumentedMutexLock l(&mutex_);
     size_t ret = 0;
-    for (auto it = map_.begin(); it != map_.end(); it++) {
-      if (it->second->IsValid()) {
+    for (const auto& fn_info : map_) {
+      if (fn_info.second->IsValid()) {
         ret++;
       }
     }
@@ -220,10 +222,13 @@ class Timer {
         executing_task_ = false;
         cond_var_.SignalAll();
 
-        // Remove the work from the heap once it is done executing.
+        // Remove the work from the heap once it is done executing, make sure
+        // it's the same function after executing the work while mutex is
+        // released.
         // Note that we are just removing the pointer from the heap. Its
         // memory is still managed in the map (as it holds a unique ptr).
         // So current_fn is still a valid ptr.
+        assert(heap_.top() == current_fn);
         heap_.pop();
 
         // current_fn may be cancelled already.
@@ -234,6 +239,10 @@ class Timer {
 
           // Schedule new work into the heap with new time.
           heap_.push(current_fn);
+        } else {
+          // if current_fn is cancelled or no need to repeat, remove it from the
+          // map to avoid leak.
+          map_.erase(current_fn->name);
         }
       } else {
         cond_var_.TimedWait(current_fn->next_run_time_us);
@@ -280,10 +289,10 @@ class Timer {
     // calls `Cancel()`.
     bool valid;
 
-    FunctionInfo(std::function<void()>&& _fn, const std::string& _name,
+    FunctionInfo(std::function<void()>&& _fn, std::string _name,
                  const uint64_t _next_run_time_us, uint64_t _repeat_every_us)
         : fn(std::move(_fn)),
-          name(_name),
+          name(std::move(_name)),
           next_run_time_us(_next_run_time_us),
           repeat_every_us(_repeat_every_us),
           valid(true) {}

util/timer_test.cc

@@ -273,33 +273,32 @@ TEST_F(TimerTest, AddSameFuncName) {
   ASSERT_TRUE(timer.Start());
 
   int func_counter1 = 0;
-  timer.Add([&] { func_counter1++; }, "duplicated_func", kInitDelayUs,
-            kRepeat1Us);
+  ASSERT_TRUE(timer.Add([&] { func_counter1++; }, "duplicated_func",
+                        kInitDelayUs, kRepeat1Us));
 
   int func2_counter = 0;
-  timer.Add([&] { func2_counter++; }, "func2", kInitDelayUs, kRepeat2Us);
+  ASSERT_TRUE(
+      timer.Add([&] { func2_counter++; }, "func2", kInitDelayUs, kRepeat2Us));
 
-  // New function with the same name should override the existing one
+  // New function with the same name should fail to add
   int func_counter2 = 0;
-  timer.Add([&] { func_counter2++; }, "duplicated_func", kInitDelayUs,
-            kRepeat1Us);
+  ASSERT_FALSE(timer.Add([&] { func_counter2++; }, "duplicated_func",
+                         kInitDelayUs, kRepeat1Us));
 
   ASSERT_EQ(0, func_counter1);
   ASSERT_EQ(0, func2_counter);
-  ASSERT_EQ(0, func_counter2);
 
   timer.TEST_WaitForRun(
       [&] { mock_clock_->SleepForMicroseconds(kInitDelayUs); });
 
-  ASSERT_EQ(0, func_counter1);
+  ASSERT_EQ(1, func_counter1);
   ASSERT_EQ(1, func2_counter);
-  ASSERT_EQ(1, func_counter2);
 
   timer.TEST_WaitForRun([&] { mock_clock_->SleepForMicroseconds(kRepeat1Us); });
 
-  ASSERT_EQ(0, func_counter1);
+  ASSERT_EQ(2, func_counter1);
   ASSERT_EQ(2, func2_counter);
-  ASSERT_EQ(2, func_counter2);
+  ASSERT_EQ(0, func_counter2);
 
   ASSERT_TRUE(timer.Shutdown());
 }