Make MemoryAllocator into a Customizable class (#8980)

Summary:
- Make MemoryAllocator and its implementations into a Customizable class.
- Added a "DefaultMemoryAllocator" which uses new and delete
- Added a "CountedMemoryAllocator" that counts the number of allocs and free
- Updated the existing tests to use these new allocators
- Changed the memkind allocator test into a generic test that can test the various allocators.
- Added tests for creating all of the allocators
- Added tests to verify/create the JemallocNodumpAllocator using its options.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8980

Reviewed By: zhichao-cao

Differential Revision: D32990403

Pulled By: mrambacher

fbshipit-source-id: 6fdfe8218c10dd8dfef34344a08201be1fa95c76

CMakeLists.txt

@@ -746,6 +746,7 @@ set(SOURCES
         memory/concurrent_arena.cc
         memory/jemalloc_nodump_allocator.cc
         memory/memkind_kmem_allocator.cc
+        memory/memory_allocator.cc
         memtable/alloc_tracker.cc
         memtable/hash_linklist_rep.cc
         memtable/hash_skiplist_rep.cc
@@ -1270,7 +1271,7 @@ if(WITH_TESTS)
         logging/env_logger_test.cc
         logging/event_logger_test.cc
         memory/arena_test.cc
-        memory/memkind_kmem_allocator_test.cc
+        memory/memory_allocator_test.cc
         memtable/inlineskiplist_test.cc
         memtable/skiplist_test.cc
         memtable/write_buffer_manager_test.cc

Makefile

@@ -1361,7 +1361,7 @@ db_repl_stress: $(OBJ_DIR)/tools/db_repl_stress.o $(LIBRARY)
 arena_test: $(OBJ_DIR)/memory/arena_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
-memkind_kmem_allocator_test: memory/memkind_kmem_allocator_test.o $(TEST_LIBRARY) $(LIBRARY)
+memory_allocator_test: memory/memory_allocator_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
 autovector_test: $(OBJ_DIR)/util/autovector_test.o $(TEST_LIBRARY) $(LIBRARY)

TARGETS

@@ -256,6 +256,7 @@ cpp_library(
         "memory/concurrent_arena.cc",
         "memory/jemalloc_nodump_allocator.cc",
         "memory/memkind_kmem_allocator.cc",
+        "memory/memory_allocator.cc",
         "memtable/alloc_tracker.cc",
         "memtable/hash_linklist_rep.cc",
         "memtable/hash_skiplist_rep.cc",
@@ -586,6 +587,7 @@ cpp_library(
         "memory/concurrent_arena.cc",
         "memory/jemalloc_nodump_allocator.cc",
         "memory/memkind_kmem_allocator.cc",
+        "memory/memory_allocator.cc",
         "memtable/alloc_tracker.cc",
         "memtable/hash_linklist_rep.cc",
         "memtable/hash_skiplist_rep.cc",
@@ -1781,8 +1783,8 @@ ROCKS_TESTS = [
         [],
     ],
     [
-        "memkind_kmem_allocator_test",
+        "memory_allocator_test",
-        "memory/memkind_kmem_allocator_test.cc",
+        "memory/memory_allocator_test.cc",
         "parallel",
         [],
         [],

db/db_impl/db_impl_write.cc

@@ -1660,8 +1660,8 @@ Status DBImpl::TrimMemtableHistory(WriteContext* context) {
   }
   for (auto& cfd : cfds) {
     autovector<MemTable*> to_delete;
-    bool trimmed = cfd->imm()->TrimHistory(
+    bool trimmed = cfd->imm()->TrimHistory(&context->memtables_to_free_,
-        &context->memtables_to_free_, cfd->mem()->MemoryAllocatedBytes());
+                                           cfd->mem()->MemoryAllocatedBytes());
     if (trimmed) {
       context->superversion_context.NewSuperVersion();
       assert(context->superversion_context.new_superversion.get() != nullptr);

db/memtable_list.cc

@@ -597,8 +597,8 @@ size_t MemTableList::ApproximateUnflushedMemTablesMemoryUsage() {
 size_t MemTableList::ApproximateMemoryUsage() { return current_memory_usage_; }
 
 size_t MemTableList::MemoryAllocatedBytesExcludingLast() const {
-  const size_t usage =
+  const size_t usage = current_memory_allocted_bytes_excluding_last_.load(
-      current_memory_allocted_bytes_excluding_last_.load(std::memory_order_relaxed);
+      std::memory_order_relaxed);
   return usage;
 }
 
@@ -610,8 +610,8 @@ bool MemTableList::HasHistory() const {
 void MemTableList::UpdateCachedValuesFromMemTableListVersion() {
   const size_t total_memtable_size =
       current_->MemoryAllocatedBytesExcludingLast();
-  current_memory_allocted_bytes_excluding_last_.store(total_memtable_size,
+  current_memory_allocted_bytes_excluding_last_.store(
-                                             std::memory_order_relaxed);
+      total_memtable_size, std::memory_order_relaxed);
 
   const bool has_history = current_->HasHistory();
   current_has_history_.store(has_history, std::memory_order_relaxed);

db/memtable_list.h

@@ -287,9 +287,9 @@ class MemTableList {
   // Returns the cached current_has_history_ value.
   bool HasHistory() const;
 
-  // Updates current_memory_allocted_bytes_excluding_last_ and current_has_history_
+  // Updates current_memory_allocted_bytes_excluding_last_ and
-  // from MemTableListVersion. Must be called whenever InstallNewVersion is
+  // current_has_history_ from MemTableListVersion. Must be called whenever
-  // called.
+  // InstallNewVersion is called.
   void UpdateCachedValuesFromMemTableListVersion();
 
   // `usage` is the current size of the mutable Memtable. When

db_stress_tool/db_stress_listener.cc

@@ -33,8 +33,8 @@ UniqueIdVerifier::UniqueIdVerifier(const std::string& db_name)
 
   Status st = fs.CreateDirIfMissing(db_name, opts, nullptr);
   if (!st.ok()) {
-    fprintf(stderr, "Failed to create directory %s: %s\n",
+    fprintf(stderr, "Failed to create directory %s: %s\n", db_name.c_str(),
-		    db_name.c_str(), st.ToString().c_str());
+            st.ToString().c_str());
     exit(1);
   }
 

include/rocksdb/memory_allocator.h

@@ -5,22 +5,23 @@
 
 #pragma once
 
-#include "rocksdb/status.h"
-
 #include <memory>
 
+#include "rocksdb/customizable.h"
+#include "rocksdb/status.h"
+
 namespace ROCKSDB_NAMESPACE {
 
 // MemoryAllocator is an interface that a client can implement to supply custom
 // memory allocation and deallocation methods. See rocksdb/cache.h for more
 // information.
 // All methods should be thread-safe.
-class MemoryAllocator {
+class MemoryAllocator : public Customizable {
  public:
-  virtual ~MemoryAllocator() = default;
+  static const char* Type() { return "MemoryAllocator"; }
-
+  static Status CreateFromString(const ConfigOptions& options,
-  // Name of the cache allocator, printed in the log
+                                 const std::string& value,
-  virtual const char* Name() const = 0;
+                                 std::shared_ptr<MemoryAllocator>* result);
 
   // Allocate a block of at least size. Has to be thread-safe.
   virtual void* Allocate(size_t size) = 0;
@@ -34,9 +35,12 @@ class MemoryAllocator {
     // default implementation just returns the allocation size
     return allocation_size;
   }
+
+  std::string GetId() const override { return GenerateIndividualId(); }
 };
 
 struct JemallocAllocatorOptions {
+  static const char* kName() { return "JemallocAllocatorOptions"; }
   // Jemalloc tcache cache allocations by size class. For each size class,
   // it caches between 20 (for large size classes) to 200 (for small size
   // classes). To reduce tcache memory usage in case the allocator is access

memory/jemalloc_nodump_allocator.cc

@@ -10,22 +10,175 @@
 
 #include "port/likely.h"
 #include "port/port.h"
+#include "rocksdb/convenience.h"
+#include "rocksdb/utilities/customizable_util.h"
+#include "rocksdb/utilities/object_registry.h"
+#include "rocksdb/utilities/options_type.h"
 #include "util/string_util.h"
 
 namespace ROCKSDB_NAMESPACE {
 
 #ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
-
 std::atomic<extent_alloc_t*> JemallocNodumpAllocator::original_alloc_{nullptr};
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+
+static std::unordered_map<std::string, OptionTypeInfo> jemalloc_type_info = {
+#ifndef ROCKSDB_LITE
+    {"limit_tcache_size",
+     {offsetof(struct JemallocAllocatorOptions, limit_tcache_size),
+      OptionType::kBoolean, OptionVerificationType::kNormal,
+      OptionTypeFlags::kNone}},
+    {"tcache_size_lower_bound",
+     {offsetof(struct JemallocAllocatorOptions, tcache_size_lower_bound),
+      OptionType::kSizeT, OptionVerificationType::kNormal,
+      OptionTypeFlags::kNone}},
+    {"tcache_size_upper_bound",
+     {offsetof(struct JemallocAllocatorOptions, tcache_size_upper_bound),
+      OptionType::kSizeT, OptionVerificationType::kNormal,
+      OptionTypeFlags::kNone}},
+#endif  // ROCKSDB_LITE
+};
+bool JemallocNodumpAllocator::IsSupported(std::string* why) {
+#ifndef ROCKSDB_JEMALLOC
+  *why = "Not compiled with ROCKSDB_JEMALLOC";
+  return false;
+#else
+  static const std::string unsupported =
+      "JemallocNodumpAllocator only available with jemalloc version >= 5 "
+      "and MADV_DONTDUMP is available.";
+  if (!HasJemalloc()) {
+    *why = unsupported;
+    return false;
+  }
+#ifndef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+  *why = unsupported;
+  return false;
+#else
+  return true;
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+#endif  // ROCKSDB_MALLOC
+}
 
 JemallocNodumpAllocator::JemallocNodumpAllocator(
-    JemallocAllocatorOptions& options,
+    JemallocAllocatorOptions& options)
-    std::unique_ptr<extent_hooks_t>&& arena_hooks, unsigned arena_index)
     : options_(options),
-      arena_hooks_(std::move(arena_hooks)),
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
-      arena_index_(arena_index),
+      tcache_(&JemallocNodumpAllocator::DestroyThreadSpecificCache),
-      tcache_(&JemallocNodumpAllocator::DestroyThreadSpecificCache) {}
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+      arena_index_(0) {
+  RegisterOptions(&options_, &jemalloc_type_info);
+}
 
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+JemallocNodumpAllocator::~JemallocNodumpAllocator() {
+  // Destroy tcache before destroying arena.
+  autovector<void*> tcache_list;
+  tcache_.Scrape(&tcache_list, nullptr);
+  for (void* tcache_index : tcache_list) {
+    DestroyThreadSpecificCache(tcache_index);
+  }
+  if (arena_index_ > 0) {
+    // Destroy arena. Silently ignore error.
+    Status s = DestroyArena(arena_index_);
+    assert(s.ok());
+    s.PermitUncheckedError();
+  }
+}
+
+size_t JemallocNodumpAllocator::UsableSize(void* p,
+                                           size_t /*allocation_size*/) const {
+  return malloc_usable_size(static_cast<void*>(p));
+}
+
+void* JemallocNodumpAllocator::Allocate(size_t size) {
+  int tcache_flag = GetThreadSpecificCache(size);
+  return mallocx(size, MALLOCX_ARENA(arena_index_) | tcache_flag);
+}
+
+void JemallocNodumpAllocator::Deallocate(void* p) {
+  // Obtain tcache.
+  size_t size = 0;
+  if (options_.limit_tcache_size) {
+    size = malloc_usable_size(p);
+  }
+  int tcache_flag = GetThreadSpecificCache(size);
+  // No need to pass arena index to dallocx(). Jemalloc will find arena index
+  // from its own metadata.
+  dallocx(p, tcache_flag);
+}
+
+Status JemallocNodumpAllocator::InitializeArenas() {
+  // Create arena.
+  size_t arena_index_size = sizeof(arena_index_);
+  int ret =
+      mallctl("arenas.create", &arena_index_, &arena_index_size, nullptr, 0);
+  if (ret != 0) {
+    return Status::Incomplete("Failed to create jemalloc arena, error code: " +
+                              ROCKSDB_NAMESPACE::ToString(ret));
+  }
+  assert(arena_index_ != 0);
+
+  // Read existing hooks.
+  std::string key =
+      "arena." + ROCKSDB_NAMESPACE::ToString(arena_index_) + ".extent_hooks";
+  extent_hooks_t* hooks;
+  size_t hooks_size = sizeof(hooks);
+  ret = mallctl(key.c_str(), &hooks, &hooks_size, nullptr, 0);
+  if (ret != 0) {
+    return Status::Incomplete("Failed to read existing hooks, error code: " +
+                              ROCKSDB_NAMESPACE::ToString(ret));
+  }
+
+  // Store existing alloc.
+  extent_alloc_t* original_alloc = hooks->alloc;
+  extent_alloc_t* expected = nullptr;
+  bool success =
+      JemallocNodumpAllocator::original_alloc_.compare_exchange_strong(
+          expected, original_alloc);
+  if (!success && original_alloc != expected) {
+    return Status::Incomplete("Original alloc conflict.");
+  }
+
+  // Set the custom hook.
+  arena_hooks_.reset(new extent_hooks_t(*hooks));
+  arena_hooks_->alloc = &JemallocNodumpAllocator::Alloc;
+  extent_hooks_t* hooks_ptr = arena_hooks_.get();
+  ret = mallctl(key.c_str(), nullptr, nullptr, &hooks_ptr, sizeof(hooks_ptr));
+  if (ret != 0) {
+    return Status::Incomplete("Failed to set custom hook, error code: " +
+                              ROCKSDB_NAMESPACE::ToString(ret));
+  }
+  return Status::OK();
+}
+
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+
+Status JemallocNodumpAllocator::PrepareOptions(
+    const ConfigOptions& config_options) {
+  std::string message;
+
+  if (!IsSupported(&message)) {
+    return Status::NotSupported(message);
+  } else if (options_.limit_tcache_size &&
+             options_.tcache_size_lower_bound >=
+                 options_.tcache_size_upper_bound) {
+    return Status::InvalidArgument(
+        "tcache_size_lower_bound larger or equal to tcache_size_upper_bound.");
+  } else if (IsMutable()) {
+    Status s = MemoryAllocator::PrepareOptions(config_options);
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+    if (s.ok()) {
+      s = InitializeArenas();
+    }
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+    return s;
+  } else {
+    // Already prepared
+    return Status::OK();
+  }
+}
+
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
 int JemallocNodumpAllocator::GetThreadSpecificCache(size_t size) {
   // We always enable tcache. The only corner case is when there are a ton of
   // threads accessing with low frequency, then it could consume a lot of
@@ -50,24 +203,6 @@ int JemallocNodumpAllocator::GetThreadSpecificCache(size_t size) {
   }
   return MALLOCX_TCACHE(*tcache_index);
 }
-
-void* JemallocNodumpAllocator::Allocate(size_t size) {
-  int tcache_flag = GetThreadSpecificCache(size);
-  return mallocx(size, MALLOCX_ARENA(arena_index_) | tcache_flag);
-}
-
-void JemallocNodumpAllocator::Deallocate(void* p) {
-  // Obtain tcache.
-  size_t size = 0;
-  if (options_.limit_tcache_size) {
-    size = malloc_usable_size(p);
-  }
-  int tcache_flag = GetThreadSpecificCache(size);
-  // No need to pass arena index to dallocx(). Jemalloc will find arena index
-  // from its own metadata.
-  dallocx(p, tcache_flag);
-}
-
 void* JemallocNodumpAllocator::Alloc(extent_hooks_t* extent, void* new_addr,
                                      size_t size, size_t alignment, bool* zero,
                                      bool* commit, unsigned arena_ind) {
@@ -91,11 +226,12 @@ void* JemallocNodumpAllocator::Alloc(extent_hooks_t* extent, void* new_addr,
 
 Status JemallocNodumpAllocator::DestroyArena(unsigned arena_index) {
   assert(arena_index != 0);
-  std::string key = "arena." + ToString(arena_index) + ".destroy";
+  std::string key =
+      "arena." + ROCKSDB_NAMESPACE::ToString(arena_index) + ".destroy";
   int ret = mallctl(key.c_str(), nullptr, 0, nullptr, 0);
   if (ret != 0) {
     return Status::Incomplete("Failed to destroy jemalloc arena, error code: " +
-                              ToString(ret));
+                              ROCKSDB_NAMESPACE::ToString(ret));
   }
   return Status::OK();
 }
@@ -111,22 +247,6 @@ void JemallocNodumpAllocator::DestroyThreadSpecificCache(void* ptr) {
   delete tcache_index;
 }
 
-JemallocNodumpAllocator::~JemallocNodumpAllocator() {
-  // Destroy tcache before destroying arena.
-  autovector<void*> tcache_list;
-  tcache_.Scrape(&tcache_list, nullptr);
-  for (void* tcache_index : tcache_list) {
-    DestroyThreadSpecificCache(tcache_index);
-  }
-  // Destroy arena. Silently ignore error.
-  Status s __attribute__((__unused__)) = DestroyArena(arena_index_);
-  assert(s.ok());
-}
-
-size_t JemallocNodumpAllocator::UsableSize(void* p,
-                                           size_t /*allocation_size*/) const {
-  return malloc_usable_size(static_cast<void*>(p));
-}
 #endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
 
 Status NewJemallocNodumpAllocator(
@@ -135,72 +255,17 @@ Status NewJemallocNodumpAllocator(
   if (memory_allocator == nullptr) {
     return Status::InvalidArgument("memory_allocator must be non-null.");
   }
-  *memory_allocator = nullptr;
+#ifndef ROCKSDB_JEMALLOC
-  Status unsupported = Status::NotSupported(
-      "JemallocNodumpAllocator only available with jemalloc version >= 5 "
-      "and MADV_DONTDUMP is available.");
-#ifndef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
   (void)options;
-  return unsupported;
+  return Status::NotSupported("Not compiled with JEMALLOC");
 #else
-  if (!HasJemalloc()) {
+  std::unique_ptr<MemoryAllocator> allocator(
-    return unsupported;
+      new JemallocNodumpAllocator(options));
+  Status s = allocator->PrepareOptions(ConfigOptions());
+  if (s.ok()) {
+    memory_allocator->reset(allocator.release());
   }
-  if (options.limit_tcache_size &&
+  return s;
-      options.tcache_size_lower_bound >= options.tcache_size_upper_bound) {
+#endif
-    return Status::InvalidArgument(
-        "tcache_size_lower_bound larger or equal to tcache_size_upper_bound.");
-  }
-
-  // Create arena.
-  unsigned arena_index = 0;
-  size_t arena_index_size = sizeof(arena_index);
-  int ret =
-      mallctl("arenas.create", &arena_index, &arena_index_size, nullptr, 0);
-  if (ret != 0) {
-    return Status::Incomplete("Failed to create jemalloc arena, error code: " +
-                              ToString(ret));
-  }
-  assert(arena_index != 0);
-
-  // Read existing hooks.
-  std::string key = "arena." + ToString(arena_index) + ".extent_hooks";
-  extent_hooks_t* hooks;
-  size_t hooks_size = sizeof(hooks);
-  ret = mallctl(key.c_str(), &hooks, &hooks_size, nullptr, 0);
-  if (ret != 0) {
-    JemallocNodumpAllocator::DestroyArena(arena_index);
-    return Status::Incomplete("Failed to read existing hooks, error code: " +
-                              ToString(ret));
-  }
-
-  // Store existing alloc.
-  extent_alloc_t* original_alloc = hooks->alloc;
-  extent_alloc_t* expected = nullptr;
-  bool success =
-      JemallocNodumpAllocator::original_alloc_.compare_exchange_strong(
-          expected, original_alloc);
-  if (!success && original_alloc != expected) {
-    JemallocNodumpAllocator::DestroyArena(arena_index);
-    return Status::Incomplete("Original alloc conflict.");
-  }
-
-  // Set the custom hook.
-  std::unique_ptr<extent_hooks_t> new_hooks(new extent_hooks_t(*hooks));
-  new_hooks->alloc = &JemallocNodumpAllocator::Alloc;
-  extent_hooks_t* hooks_ptr = new_hooks.get();
-  ret = mallctl(key.c_str(), nullptr, nullptr, &hooks_ptr, sizeof(hooks_ptr));
-  if (ret != 0) {
-    JemallocNodumpAllocator::DestroyArena(arena_index);
-    return Status::Incomplete("Failed to set custom hook, error code: " +
-                              ToString(ret));
-  }
-
-  // Create cache allocator.
-  memory_allocator->reset(
-      new JemallocNodumpAllocator(options, std::move(new_hooks), arena_index));
-  return Status::OK();
-#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
 }
-
 }  // namespace ROCKSDB_NAMESPACE

memory/jemalloc_nodump_allocator.h

@@ -12,6 +12,7 @@
 #include "port/port.h"
 #include "rocksdb/memory_allocator.h"
 #include "util/thread_local.h"
+#include "utilities/memory_allocators.h"
 
 #if defined(ROCKSDB_JEMALLOC) && defined(ROCKSDB_PLATFORM_POSIX)
 
@@ -19,22 +20,38 @@
 
 #if (JEMALLOC_VERSION_MAJOR >= 5) && defined(MADV_DONTDUMP)
 #define ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+#endif  // (JEMALLOC_VERSION_MAJOR >= 5) && MADV_DONTDUMP
+#endif  // ROCKSDB_JEMALLOC && ROCKSDB_PLATFORM_POSIX
 
 namespace ROCKSDB_NAMESPACE {
-
+class JemallocNodumpAllocator : public BaseMemoryAllocator {
-class JemallocNodumpAllocator : public MemoryAllocator {
  public:
-  JemallocNodumpAllocator(JemallocAllocatorOptions& options,
+  explicit JemallocNodumpAllocator(JemallocAllocatorOptions& options);
-                          std::unique_ptr<extent_hooks_t>&& arena_hooks,
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
-                          unsigned arena_index);
   ~JemallocNodumpAllocator();
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
 
-  const char* Name() const override { return "JemallocNodumpAllocator"; }
+  static const char* kClassName() { return "JemallocNodumpAllocator"; }
+  const char* Name() const override { return kClassName(); }
+  static bool IsSupported() {
+    std::string unused;
+    return IsSupported(&unused);
+  }
+  static bool IsSupported(std::string* why);
+  bool IsMutable() const { return arena_index_ == 0; }
+
+  Status PrepareOptions(const ConfigOptions& config_options) override;
+
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
   void* Allocate(size_t size) override;
   void Deallocate(void* p) override;
   size_t UsableSize(void* p, size_t allocation_size) const override;
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
 
  private:
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+  Status InitializeArenas();
+
   friend Status NewJemallocNodumpAllocator(
       JemallocAllocatorOptions& options,
       std::shared_ptr<MemoryAllocator>* memory_allocator);
@@ -53,7 +70,10 @@ class JemallocNodumpAllocator : public MemoryAllocator {
   // Get or create tcache. Return flag suitable to use with `mallocx`:
   // either MALLOCX_TCACHE_NONE or MALLOCX_TCACHE(tc).
   int GetThreadSpecificCache(size_t size);
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
+  JemallocAllocatorOptions options_;
 
+#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
   // A function pointer to jemalloc default alloc. Use atomic to make sure
   // NewJemallocNodumpAllocator is thread-safe.
   //
@@ -61,18 +81,14 @@ class JemallocNodumpAllocator : public MemoryAllocator {
   // alloc needs to be static to pass to jemalloc as function pointer.
   static std::atomic<extent_alloc_t*> original_alloc_;
 
-  const JemallocAllocatorOptions options_;
-
   // Custom hooks has to outlive corresponding arena.
-  const std::unique_ptr<extent_hooks_t> arena_hooks_;
+  std::unique_ptr<extent_hooks_t> arena_hooks_;
-
-  // Arena index.
-  const unsigned arena_index_;
 
   // Hold thread-local tcache index.
   ThreadLocalPtr tcache_;
-};
+#endif  // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
 
+  // Arena index.
+  unsigned arena_index_;
+};
 }  // namespace ROCKSDB_NAMESPACE
-#endif  // (JEMALLOC_VERSION_MAJOR >= 5) && MADV_DONTDUMP
-#endif  // ROCKSDB_JEMALLOC && ROCKSDB_PLATFORM_POSIX

memory/memkind_kmem_allocator.cc

@@ -5,11 +5,22 @@
 //  (found in the LICENSE.Apache file in the root directory).
 
 #ifdef MEMKIND
+#include <memkind.h>
+#endif  // MEMKIND
 
-#include "memkind_kmem_allocator.h"
+#include "memory/memkind_kmem_allocator.h"
 
 namespace ROCKSDB_NAMESPACE {
+Status MemkindKmemAllocator::PrepareOptions(const ConfigOptions& options) {
+  std::string message;
+  if (!IsSupported(&message)) {
+    return Status::NotSupported(message);
+  } else {
+    return MemoryAllocator::PrepareOptions(options);
+  }
+}
 
+#ifdef MEMKIND
 void* MemkindKmemAllocator::Allocate(size_t size) {
   void* p = memkind_malloc(MEMKIND_DAX_KMEM, size);
   if (p == NULL) {
@@ -28,6 +39,6 @@ size_t MemkindKmemAllocator::UsableSize(void* p,
   return memkind_malloc_usable_size(MEMKIND_DAX_KMEM, p);
 }
 #endif  // ROCKSDB_MALLOC_USABLE_SIZE
+#endif  // MEMKIND
 
 }  // namespace ROCKSDB_NAMESPACE
-#endif  // MEMKIND

memory/memkind_kmem_allocator.h

@@ -6,22 +6,37 @@
 
 #pragma once
 
-#ifdef MEMKIND
-
-#include <memkind.h>
 #include "rocksdb/memory_allocator.h"
+#include "utilities/memory_allocators.h"
 
 namespace ROCKSDB_NAMESPACE {
 
-class MemkindKmemAllocator : public MemoryAllocator {
+class MemkindKmemAllocator : public BaseMemoryAllocator {
  public:
-  const char* Name() const override { return "MemkindKmemAllocator"; };
+  static const char* kClassName() { return "MemkindKmemAllocator"; }
+  const char* Name() const override { return kClassName(); }
+  static bool IsSupported() {
+    std::string unused;
+    return IsSupported(&unused);
+  }
+
+  static bool IsSupported(std::string* msg) {
+#ifdef MEMKIND
+    return true;
+#else
+    *msg = "Not compiled with MemKind";
+    return false;
+#endif
+  }
+  Status PrepareOptions(const ConfigOptions& options) override;
+
+#ifdef MEMKIND
   void* Allocate(size_t size) override;
   void Deallocate(void* p) override;
 #ifdef ROCKSDB_MALLOC_USABLE_SIZE
   size_t UsableSize(void* p, size_t /*allocation_size*/) const override;
 #endif
+#endif  // MEMKIND
 };
 
 }  // namespace ROCKSDB_NAMESPACE
-#endif  // MEMKIND

memory/memkind_kmem_allocator_test.cc

@@ -1,102 +0,0 @@
-//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
-//  Copyright (c) 2019 Intel Corporation
-//  This source code is licensed under both the GPLv2 (found in the
-//  COPYING file in the root directory) and Apache 2.0 License
-//  (found in the LICENSE.Apache file in the root directory).
-
-#include <cstdio>
-
-#ifdef MEMKIND
-#include "memkind_kmem_allocator.h"
-#include "rocksdb/cache.h"
-#include "rocksdb/db.h"
-#include "rocksdb/options.h"
-#include "table/block_based/block_based_table_factory.h"
-#include "test_util/testharness.h"
-
-namespace ROCKSDB_NAMESPACE {
-TEST(MemkindKmemAllocatorTest, Allocate) {
-  MemkindKmemAllocator allocator;
-  void* p;
-  try {
-    p = allocator.Allocate(1024);
-  } catch (const std::bad_alloc& e) {
-    return;
-  }
-  ASSERT_NE(p, nullptr);
-  size_t size = allocator.UsableSize(p, 1024);
-  ASSERT_GE(size, 1024);
-  allocator.Deallocate(p);
-}
-
-TEST(MemkindKmemAllocatorTest, DatabaseBlockCache) {
-  // Check if a memory node is available for allocation
-  try {
-    MemkindKmemAllocator allocator;
-    allocator.Allocate(1024);
-  } catch (const std::bad_alloc& e) {
-    return;  // if no node available, skip the test
-  }
-
-  // Create database with block cache using MemkindKmemAllocator
-  Options options;
-  std::string dbname = test::PerThreadDBPath("memkind_kmem_allocator_test");
-  ASSERT_OK(DestroyDB(dbname, options));
-
-  options.create_if_missing = true;
-  std::shared_ptr<Cache> cache = NewLRUCache(
-      1024 * 1024, 6, false, false, std::make_shared<MemkindKmemAllocator>());
-  BlockBasedTableOptions table_options;
-  table_options.block_cache = cache;
-  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
-
-  DB* db = nullptr;
-  Status s = DB::Open(options, dbname, &db);
-  ASSERT_OK(s);
-  ASSERT_NE(db, nullptr);
-  ASSERT_EQ(cache->GetUsage(), 0);
-
-  // Write 2kB (200 values, each 10 bytes)
-  int num_keys = 200;
-  WriteOptions wo;
-  std::string val = "0123456789";
-  for (int i = 0; i < num_keys; i++) {
-    std::string key = std::to_string(i);
-    s = db->Put(wo, Slice(key), Slice(val));
-    ASSERT_OK(s);
-  }
-  ASSERT_OK(db->Flush(FlushOptions()));  // Flush all data from memtable so that
-                                         // reads are from block cache
-
-  // Read and check block cache usage
-  ReadOptions ro;
-  std::string result;
-  for (int i = 0; i < num_keys; i++) {
-    std::string key = std::to_string(i);
-    s = db->Get(ro, key, &result);
-    ASSERT_OK(s);
-    ASSERT_EQ(result, val);
-  }
-  ASSERT_GT(cache->GetUsage(), 2000);
-
-  // Close database
-  s = db->Close();
-  ASSERT_OK(s);
-  ASSERT_OK(DestroyDB(dbname, options));
-}
-}  // namespace ROCKSDB_NAMESPACE
-
-int main(int argc, char** argv) {
-  ::testing::InitGoogleTest(&argc, argv);
-  return RUN_ALL_TESTS();
-}
-
-#else
-
-int main(int /*argc*/, char** /*argv*/) {
-  printf(
-      "Skip memkind_kmem_allocator_test as the required library memkind is "
-      "missing.");
-}
-
-#endif  // MEMKIND

memory/memory_allocator.cc

@@ -0,0 +1,91 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "rocksdb/memory_allocator.h"
+
+#include "memory/jemalloc_nodump_allocator.h"
+#include "memory/memkind_kmem_allocator.h"
+#include "rocksdb/utilities/customizable_util.h"
+#include "rocksdb/utilities/object_registry.h"
+#include "rocksdb/utilities/options_type.h"
+#include "utilities/memory_allocators.h"
+
+namespace ROCKSDB_NAMESPACE {
+namespace {
+static std::unordered_map<std::string, OptionTypeInfo> ma_wrapper_type_info = {
+#ifndef ROCKSDB_LITE
+    {"target", OptionTypeInfo::AsCustomSharedPtr<MemoryAllocator>(
+                   0, OptionVerificationType::kByName, OptionTypeFlags::kNone)},
+#endif  // ROCKSDB_LITE
+};
+
+#ifndef ROCKSDB_LITE
+static int RegisterBuiltinAllocators(ObjectLibrary& library,
+                                     const std::string& /*arg*/) {
+  library.Register<MemoryAllocator>(
+      DefaultMemoryAllocator::kClassName(),
+      [](const std::string& /*uri*/, std::unique_ptr<MemoryAllocator>* guard,
+         std::string* /*errmsg*/) {
+        guard->reset(new DefaultMemoryAllocator());
+        return guard->get();
+      });
+  library.Register<MemoryAllocator>(
+      CountedMemoryAllocator::kClassName(),
+      [](const std::string& /*uri*/, std::unique_ptr<MemoryAllocator>* guard,
+         std::string* /*errmsg*/) {
+        guard->reset(new CountedMemoryAllocator(
+            std::make_shared<DefaultMemoryAllocator>()));
+        return guard->get();
+      });
+  library.Register<MemoryAllocator>(
+      JemallocNodumpAllocator::kClassName(),
+      [](const std::string& /*uri*/, std::unique_ptr<MemoryAllocator>* guard,
+         std::string* errmsg) {
+        if (JemallocNodumpAllocator::IsSupported(errmsg)) {
+          JemallocAllocatorOptions options;
+          guard->reset(new JemallocNodumpAllocator(options));
+        }
+        return guard->get();
+      });
+  library.Register<MemoryAllocator>(
+      MemkindKmemAllocator::kClassName(),
+      [](const std::string& /*uri*/, std::unique_ptr<MemoryAllocator>* guard,
+         std::string* errmsg) {
+        if (MemkindKmemAllocator::IsSupported(errmsg)) {
+          guard->reset(new MemkindKmemAllocator());
+        }
+        return guard->get();
+      });
+  size_t num_types;
+  return static_cast<int>(library.GetFactoryCount(&num_types));
+}
+#endif  // ROCKSDB_LITE
+}  // namespace
+
+MemoryAllocatorWrapper::MemoryAllocatorWrapper(
+    const std::shared_ptr<MemoryAllocator>& t)
+    : target_(t) {
+  RegisterOptions("", &target_, &ma_wrapper_type_info);
+}
+
+Status MemoryAllocator::CreateFromString(
+    const ConfigOptions& options, const std::string& value,
+    std::shared_ptr<MemoryAllocator>* result) {
+#ifndef ROCKSDB_LITE
+  static std::once_flag once;
+  std::call_once(once, [&]() {
+    RegisterBuiltinAllocators(*(ObjectLibrary::Default().get()), "");
+  });
+#else
+  if (value == DefaultMemoryAllocator::kClassName()) {
+    result->reset(new DefaultMemoryAllocator());
+    return Status::OK();
+  }
+#endif  // ROCKSDB_LITE
+  ConfigOptions copy = options;
+  copy.invoke_prepare_options = true;
+  return LoadManagedObject<MemoryAllocator>(copy, value, result);
+}
+}  // namespace ROCKSDB_NAMESPACE

memory/memory_allocator_test.cc

@@ -0,0 +1,236 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  Copyright (c) 2019 Intel Corporation
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include <cstdio>
+
+#include "memory/jemalloc_nodump_allocator.h"
+#include "memory/memkind_kmem_allocator.h"
+#include "rocksdb/cache.h"
+#include "rocksdb/convenience.h"
+#include "rocksdb/db.h"
+#include "rocksdb/options.h"
+#include "table/block_based/block_based_table_factory.h"
+#include "test_util/testharness.h"
+#include "utilities/memory_allocators.h"
+
+namespace ROCKSDB_NAMESPACE {
+class MemoryAllocatorTest
+    : public testing::Test,
+      public ::testing::WithParamInterface<std::tuple<std::string, bool>> {
+ public:
+  MemoryAllocatorTest() {
+    std::tie(id_, supported_) = GetParam();
+    Status s =
+        MemoryAllocator::CreateFromString(ConfigOptions(), id_, &allocator_);
+    if (supported_) {
+      EXPECT_OK(s);
+    } else if (!s.ok()) {
+      EXPECT_TRUE(s.IsNotSupported());
+    }
+  }
+  bool IsSupported() { return supported_; }
+
+  std::shared_ptr<MemoryAllocator> allocator_;
+  std::string id_;
+
+ private:
+  bool supported_;
+};
+
+TEST_P(MemoryAllocatorTest, Allocate) {
+  if (!IsSupported()) {
+    return;
+  }
+  void* p = allocator_->Allocate(1024);
+  ASSERT_NE(p, nullptr);
+  size_t size = allocator_->UsableSize(p, 1024);
+  ASSERT_GE(size, 1024);
+  allocator_->Deallocate(p);
+}
+
+TEST_P(MemoryAllocatorTest, CreateAllocator) {
+  ConfigOptions config_options;
+  config_options.ignore_unknown_options = false;
+  config_options.ignore_unsupported_options = false;
+  std::shared_ptr<MemoryAllocator> orig, copy;
+  Status s = MemoryAllocator::CreateFromString(config_options, id_, &orig);
+  if (!IsSupported()) {
+    ASSERT_TRUE(s.IsNotSupported());
+  } else {
+    ASSERT_OK(s);
+    ASSERT_NE(orig, nullptr);
+#ifndef ROCKSDB_LITE
+    std::string str = orig->ToString(config_options);
+    ASSERT_OK(MemoryAllocator::CreateFromString(config_options, str, &copy));
+    ASSERT_EQ(orig, copy);
+#endif  // ROCKSDB_LITE
+  }
+}
+
+TEST_P(MemoryAllocatorTest, DatabaseBlockCache) {
+  if (!IsSupported()) {
+    // Check if a memory node is available for allocation
+  }
+
+  // Create database with block cache using the MemoryAllocator
+  Options options;
+  std::string dbname = test::PerThreadDBPath("allocator_test");
+  ASSERT_OK(DestroyDB(dbname, options));
+
+  options.create_if_missing = true;
+  BlockBasedTableOptions table_options;
+  auto cache = NewLRUCache(1024 * 1024, 6, false, false, allocator_);
+  table_options.block_cache = cache;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  DB* db = nullptr;
+  Status s = DB::Open(options, dbname, &db);
+  ASSERT_OK(s);
+  ASSERT_NE(db, nullptr);
+  ASSERT_LE(cache->GetUsage(), 104);  // Cache will contain stats
+
+  // Write 2kB (200 values, each 10 bytes)
+  int num_keys = 200;
+  WriteOptions wo;
+  std::string val = "0123456789";
+  for (int i = 0; i < num_keys; i++) {
+    std::string key = std::to_string(i);
+    s = db->Put(wo, Slice(key), Slice(val));
+    ASSERT_OK(s);
+  }
+  ASSERT_OK(db->Flush(FlushOptions()));  // Flush all data from memtable so that
+                                         // reads are from block cache
+
+  // Read and check block cache usage
+  ReadOptions ro;
+  std::string result;
+  for (int i = 0; i < num_keys; i++) {
+    std::string key = std::to_string(i);
+    s = db->Get(ro, key, &result);
+    ASSERT_OK(s);
+    ASSERT_EQ(result, val);
+  }
+  ASSERT_GT(cache->GetUsage(), 2000);
+
+  // Close database
+  s = db->Close();
+  ASSERT_OK(s);
+  delete db;
+  ASSERT_OK(DestroyDB(dbname, options));
+}
+
+class CreateMemoryAllocatorTest : public testing::Test {
+ public:
+  CreateMemoryAllocatorTest() {
+    config_options_.ignore_unknown_options = false;
+    config_options_.ignore_unsupported_options = false;
+  }
+  ConfigOptions config_options_;
+};
+
+TEST_F(CreateMemoryAllocatorTest, JemallocOptionsTest) {
+  std::shared_ptr<MemoryAllocator> allocator;
+  std::string id = std::string("id=") + JemallocNodumpAllocator::kClassName();
+  Status s = MemoryAllocator::CreateFromString(config_options_, id, &allocator);
+  if (!JemallocNodumpAllocator::IsSupported()) {
+    ASSERT_TRUE(s.IsNotSupported());
+    ROCKSDB_GTEST_SKIP("JEMALLOC not supported");
+    return;
+  }
+  ASSERT_OK(s);
+  ASSERT_NE(allocator, nullptr);
+  JemallocAllocatorOptions jopts;
+  auto opts = allocator->GetOptions<JemallocAllocatorOptions>();
+  ASSERT_NE(opts, nullptr);
+  ASSERT_EQ(opts->limit_tcache_size, jopts.limit_tcache_size);
+  ASSERT_EQ(opts->tcache_size_lower_bound, jopts.tcache_size_lower_bound);
+  ASSERT_EQ(opts->tcache_size_upper_bound, jopts.tcache_size_upper_bound);
+
+  ASSERT_NOK(MemoryAllocator::CreateFromString(
+      config_options_,
+      id + "; limit_tcache_size=true; tcache_size_lower_bound=4096; "
+           "tcache_size_upper_bound=1024",
+      &allocator));
+  ASSERT_OK(MemoryAllocator::CreateFromString(
+      config_options_,
+      id + "; limit_tcache_size=false; tcache_size_lower_bound=4096; "
+           "tcache_size_upper_bound=1024",
+      &allocator));
+  opts = allocator->GetOptions<JemallocAllocatorOptions>();
+  ASSERT_NE(opts, nullptr);
+  ASSERT_EQ(opts->limit_tcache_size, false);
+  ASSERT_EQ(opts->tcache_size_lower_bound, 4096U);
+  ASSERT_EQ(opts->tcache_size_upper_bound, 1024U);
+  ASSERT_OK(MemoryAllocator::CreateFromString(
+      config_options_,
+      id + "; limit_tcache_size=true; tcache_size_upper_bound=4096; "
+           "tcache_size_lower_bound=1024",
+      &allocator));
+  opts = allocator->GetOptions<JemallocAllocatorOptions>();
+  ASSERT_NE(opts, nullptr);
+  ASSERT_EQ(opts->limit_tcache_size, true);
+  ASSERT_EQ(opts->tcache_size_lower_bound, 1024U);
+  ASSERT_EQ(opts->tcache_size_upper_bound, 4096U);
+}
+
+TEST_F(CreateMemoryAllocatorTest, NewJemallocNodumpAllocator) {
+  JemallocAllocatorOptions jopts;
+  std::shared_ptr<MemoryAllocator> allocator;
+
+  jopts.limit_tcache_size = true;
+  jopts.tcache_size_lower_bound = 2 * 1024;
+  jopts.tcache_size_upper_bound = 1024;
+
+  ASSERT_NOK(NewJemallocNodumpAllocator(jopts, nullptr));
+  Status s = NewJemallocNodumpAllocator(jopts, &allocator);
+  std::string msg;
+  if (!JemallocNodumpAllocator::IsSupported(&msg)) {
+    ASSERT_TRUE(s.IsNotSupported());
+    ROCKSDB_GTEST_SKIP("JEMALLOC not supported");
+    return;
+  }
+  ASSERT_NOK(s);  // Invalid options
+  ASSERT_EQ(allocator, nullptr);
+
+  jopts.tcache_size_upper_bound = 4 * 1024;
+  ASSERT_OK(NewJemallocNodumpAllocator(jopts, &allocator));
+  ASSERT_NE(allocator, nullptr);
+  auto opts = allocator->GetOptions<JemallocAllocatorOptions>();
+  ASSERT_EQ(opts->tcache_size_upper_bound, jopts.tcache_size_upper_bound);
+  ASSERT_EQ(opts->tcache_size_lower_bound, jopts.tcache_size_lower_bound);
+  ASSERT_EQ(opts->limit_tcache_size, jopts.limit_tcache_size);
+
+  jopts.limit_tcache_size = false;
+  ASSERT_OK(NewJemallocNodumpAllocator(jopts, &allocator));
+  ASSERT_NE(allocator, nullptr);
+  opts = allocator->GetOptions<JemallocAllocatorOptions>();
+  ASSERT_EQ(opts->tcache_size_upper_bound, jopts.tcache_size_upper_bound);
+  ASSERT_EQ(opts->tcache_size_lower_bound, jopts.tcache_size_lower_bound);
+  ASSERT_EQ(opts->limit_tcache_size, jopts.limit_tcache_size);
+}
+
+INSTANTIATE_TEST_CASE_P(DefaultMemoryAllocator, MemoryAllocatorTest,
+                        ::testing::Values(std::make_tuple(
+                            DefaultMemoryAllocator::kClassName(), true)));
+#ifdef MEMKIND
+INSTANTIATE_TEST_CASE_P(
+    MemkindkMemAllocator, MemoryAllocatorTest,
+    ::testing::Values(std::make_tuple(MemkindKmemAllocator::kClassName(),
+                                      MemkindKmemAllocator::IsSupported())));
+#endif  // MEMKIND
+
+#ifdef ROCKSDB_JEMALLOC
+INSTANTIATE_TEST_CASE_P(
+    JemallocNodumpAllocator, MemoryAllocatorTest,
+    ::testing::Values(std::make_tuple(JemallocNodumpAllocator::kClassName(),
+                                      JemallocNodumpAllocator::IsSupported())));
+#endif  // ROCKSDB_JEMALLOC
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

options/customizable_test.cc

@@ -22,6 +22,7 @@
 #include "rocksdb/env_encryption.h"
 #include "rocksdb/file_checksum.h"
 #include "rocksdb/flush_block_policy.h"
+#include "rocksdb/memory_allocator.h"
 #include "rocksdb/rate_limiter.h"
 #include "rocksdb/secondary_cache.h"
 #include "rocksdb/slice_transform.h"
@@ -39,6 +40,7 @@
 #include "util/rate_limiter.h"
 #include "util/string_util.h"
 #include "utilities/compaction_filters/remove_emptyvalue_compactionfilter.h"
+#include "utilities/memory_allocators.h"
 
 #ifndef GFLAGS
 bool FLAGS_enable_print = false;
@@ -1305,6 +1307,12 @@ class MockSliceTransform : public SliceTransform {
   bool InRange(const Slice& /*key*/) const override { return false; }
 };
 
+class MockMemoryAllocator : public BaseMemoryAllocator {
+ public:
+  static const char* kClassName() { return "MockMemoryAllocator"; }
+  const char* Name() const override { return kClassName(); }
+};
+
 #ifndef ROCKSDB_LITE
 class MockEncryptionProvider : public EncryptionProvider {
  public:
@@ -1463,6 +1471,13 @@ static int RegisterLocalObjects(ObjectLibrary& library,
     guard->reset(new MockCipher());
     return guard->get();
   });
+  library.Register<MemoryAllocator>(
+      MockMemoryAllocator::kClassName(),
+      [](const std::string& /*uri*/, std::unique_ptr<MemoryAllocator>* guard,
+         std::string* /* errmsg */) {
+        guard->reset(new MockMemoryAllocator());
+        return guard->get();
+      });
   library.Register<FlushBlockPolicyFactory>(
       TestFlushBlockPolicyFactory::kClassName(),
       [](const std::string& /*uri*/,
@@ -1921,6 +1936,22 @@ TEST_F(LoadCustomizableTest, LoadSystemClockTest) {
   }
 }
 
+TEST_F(LoadCustomizableTest, LoadMemoryAllocatorTest) {
+  std::shared_ptr<MemoryAllocator> result;
+  ASSERT_NOK(MemoryAllocator::CreateFromString(
+      config_options_, MockMemoryAllocator::kClassName(), &result));
+  ASSERT_OK(MemoryAllocator::CreateFromString(
+      config_options_, DefaultMemoryAllocator::kClassName(), &result));
+  ASSERT_NE(result, nullptr);
+  ASSERT_STREQ(result->Name(), DefaultMemoryAllocator::kClassName());
+  if (RegisterTests("Test")) {
+    ASSERT_OK(MemoryAllocator::CreateFromString(
+        config_options_, MockMemoryAllocator::kClassName(), &result));
+    ASSERT_NE(result, nullptr);
+    ASSERT_STREQ(result->Name(), MockMemoryAllocator::kClassName());
+  }
+}
+
 TEST_F(LoadCustomizableTest, LoadRateLimiterTest) {
   std::shared_ptr<RateLimiter> result;
   ASSERT_NOK(RateLimiter::CreateFromString(

src.mk

@@ -115,6 +115,7 @@ LIB_SOURCES =                                                   \
   memory/concurrent_arena.cc                                    \
   memory/jemalloc_nodump_allocator.cc                           \
   memory/memkind_kmem_allocator.cc                              \
+  memory/memory_allocator.cc                                    \
   memtable/alloc_tracker.cc                                     \
   memtable/hash_linklist_rep.cc                                 \
   memtable/hash_skiplist_rep.cc                                 \
@@ -501,7 +502,7 @@ TEST_MAIN_SOURCES =                                                     \
   logging/env_logger_test.cc                                            \
   logging/event_logger_test.cc                                          \
   memory/arena_test.cc                                                  \
-  memory/memkind_kmem_allocator_test.cc                                 \
+  memory/memory_allocator_test.cc                                       \
   memtable/inlineskiplist_test.cc                                       \
   memtable/skiplist_test.cc                                             \
   memtable/write_buffer_manager_test.cc                                 \

table/block_fetcher_test.cc

@@ -18,32 +18,10 @@
 #include "table/block_based/block_based_table_reader.h"
 #include "table/format.h"
 #include "test_util/testharness.h"
+#include "utilities/memory_allocators.h"
 
 namespace ROCKSDB_NAMESPACE {
 namespace {
-
-class CountedMemoryAllocator : public MemoryAllocator {
- public:
-  const char* Name() const override { return "CountedMemoryAllocator"; }
-
-  void* Allocate(size_t size) override {
-    num_allocations_++;
-    return static_cast<void*>(new char[size]);
-  }
-
-  void Deallocate(void* p) override {
-    num_deallocations_++;
-    delete[] static_cast<char*>(p);
-  }
-
-  int GetNumAllocations() const { return num_allocations_; }
-  int GetNumDeallocations() const { return num_deallocations_; }
-
- private:
-  int num_allocations_ = 0;
-  int num_deallocations_ = 0;
-};
-
 struct MemcpyStats {
   int num_stack_buf_memcpy;
   int num_heap_buf_memcpy;

table/table_test.cc

@@ -69,6 +69,7 @@
 #include "util/file_checksum_helper.h"
 #include "util/random.h"
 #include "util/string_util.h"
+#include "utilities/memory_allocators.h"
 #include "utilities/merge_operators.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -3635,30 +3636,10 @@ TEST_P(BlockBasedTableTest, BlockCacheLeak) {
   c.ResetTableReader();
 }
 
-namespace {
-class CustomMemoryAllocator : public MemoryAllocator {
- public:
-  const char* Name() const override { return "CustomMemoryAllocator"; }
-
-  void* Allocate(size_t size) override {
-    ++numAllocations;
-    auto ptr = new char[size + 16];
-    memcpy(ptr, "memory_allocator_", 16);  // mangle first 16 bytes
-    return reinterpret_cast<void*>(ptr + 16);
-  }
-  void Deallocate(void* p) override {
-    ++numDeallocations;
-    char* ptr = reinterpret_cast<char*>(p) - 16;
-    delete[] ptr;
-  }
-
-  std::atomic<int> numAllocations;
-  std::atomic<int> numDeallocations;
-};
-}  // namespace
-
 TEST_P(BlockBasedTableTest, MemoryAllocator) {
-  auto custom_memory_allocator = std::make_shared<CustomMemoryAllocator>();
+  auto default_memory_allocator = std::make_shared<DefaultMemoryAllocator>();
+  auto custom_memory_allocator =
+      std::make_shared<CountedMemoryAllocator>(default_memory_allocator);
   {
     Options opt;
     std::unique_ptr<InternalKeyComparator> ikc;
@@ -3701,10 +3682,10 @@ TEST_P(BlockBasedTableTest, MemoryAllocator) {
 
   // out of scope, block cache should have been deleted, all allocations
   // deallocated
-  EXPECT_EQ(custom_memory_allocator->numAllocations.load(),
+  EXPECT_EQ(custom_memory_allocator->GetNumAllocations(),
-            custom_memory_allocator->numDeallocations.load());
+            custom_memory_allocator->GetNumDeallocations());
   // make sure that allocations actually happened through the cache allocator
-  EXPECT_GT(custom_memory_allocator->numAllocations.load(), 0);
+  EXPECT_GT(custom_memory_allocator->GetNumAllocations(), 0);
 }
 
 // Test the file checksum of block based table

utilities/memory_allocators.h

@@ -0,0 +1,104 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <atomic>
+
+#include "rocksdb/memory_allocator.h"
+
+namespace ROCKSDB_NAMESPACE {
+// A memory allocator using new/delete
+class DefaultMemoryAllocator : public MemoryAllocator {
+ public:
+  static const char* kClassName() { return "DefaultMemoryAllocator"; }
+  const char* Name() const override { return kClassName(); }
+  void* Allocate(size_t size) override {
+    return static_cast<void*>(new char[size]);
+  }
+
+  void Deallocate(void* p) override { delete[] static_cast<char*>(p); }
+};
+
+// Base class for a MemoryAllocator.  This implementation does nothing
+// and implements the methods in failuse mode (assert if the methods are
+// invoked). Implementations can extend this class and override these methods
+// when they are enabled via compiler switches (e.g., the
+// JeMallocMemoryAllocator can define these methods if ROCKSDB_JEMALLOC is
+// defined at compile time.  If compiled in "disabled" mode, this class provides
+// default/failure implementations.  If compiled in "enabled" mode, the derived
+// class needs to provide the appopriate "enabled" methods for the "real"
+// implementation. Failure of the "real" implementation to implement ovreride
+// any of these methods will result in an assert failure.
+class BaseMemoryAllocator : public MemoryAllocator {
+ public:
+  void* Allocate(size_t /*size*/) override {
+    assert(false);
+    return nullptr;
+  }
+
+  void Deallocate(void* /*p*/) override { assert(false); }
+};
+
+// A Wrapped MemoryAllocator.  Delegates the memory allcator functions to the
+// wrapped one.
+class MemoryAllocatorWrapper : public MemoryAllocator {
+ public:
+  // Initialize an MemoryAllocatorWrapper that delegates all calls to *t
+  explicit MemoryAllocatorWrapper(const std::shared_ptr<MemoryAllocator>& t);
+  ~MemoryAllocatorWrapper() override {}
+
+  // Return the target to which to forward all calls
+  MemoryAllocator* target() const { return target_.get(); }
+  // Allocate a block of at least size. Has to be thread-safe.
+  void* Allocate(size_t size) override { return target_->Allocate(size); }
+
+  // Deallocate previously allocated block. Has to be thread-safe.
+  void Deallocate(void* p) override { return target_->Deallocate(p); }
+
+  // Returns the memory size of the block allocated at p. The default
+  // implementation that just returns the original allocation_size is fine.
+  size_t UsableSize(void* p, size_t allocation_size) const override {
+    return target_->UsableSize(p, allocation_size);
+  }
+
+  const Customizable* Inner() const override { return target_.get(); }
+
+ protected:
+  std::shared_ptr<MemoryAllocator> target_;
+};
+
+// A memory allocator that counts the number of allocations and deallocations
+// This class is useful if the number of memory allocations/dellocations is
+// important.
+class CountedMemoryAllocator : public MemoryAllocatorWrapper {
+ public:
+  CountedMemoryAllocator()
+      : MemoryAllocatorWrapper(std::make_shared<DefaultMemoryAllocator>()),
+        allocations_(0),
+        deallocations_(0) {}
+
+  explicit CountedMemoryAllocator(const std::shared_ptr<MemoryAllocator>& t)
+      : MemoryAllocatorWrapper(t), allocations_(0), deallocations_(0) {}
+  static const char* kClassName() { return "CountedMemoryAllocator"; }
+  const char* Name() const override { return kClassName(); }
+  std::string GetId() const override { return std::string(Name()); }
+  void* Allocate(size_t size) override {
+    allocations_++;
+    return MemoryAllocatorWrapper::Allocate(size);
+  }
+
+  void Deallocate(void* p) override {
+    deallocations_++;
+    MemoryAllocatorWrapper::Deallocate(p);
+  }
+  uint64_t GetNumAllocations() const { return allocations_; }
+  uint64_t GetNumDeallocations() const { return deallocations_; }
+
+ private:
+  std::atomic<uint64_t> allocations_;
+  std::atomic<uint64_t> deallocations_;
+};
+}  // namespace ROCKSDB_NAMESPACE