Range Locking: Implementation of range locking (#7506)

Summary:
Range Locking - an implementation based on the locktree library

- Add a RangeTreeLockManager and RangeTreeLockTracker which implement
  range locking using the locktree library.
- Point locks are handled as locks on single-point ranges.
- Add a unit test: range_locking_test

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7506

Reviewed By: akankshamahajan15

Differential Revision: D25320703

Pulled By: cheng-chang

fbshipit-source-id: f86347384b42ba2b0257d67eca0f45f806b69da7

CMakeLists.txt

@@ -814,6 +814,8 @@ set(SOURCES
         utilities/transactions/lock/lock_manager.cc
         utilities/transactions/lock/point/point_lock_tracker.cc
         utilities/transactions/lock/point/point_lock_manager.cc
+        utilities/transactions/lock/range/range_tree/range_tree_lock_manager.cc
+        utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.cc
         utilities/transactions/optimistic_transaction_db_impl.cc
         utilities/transactions/optimistic_transaction.cc
         utilities/transactions/pessimistic_transaction.cc
@@ -831,7 +833,7 @@ set(SOURCES
         utilities/write_batch_with_index/write_batch_with_index_internal.cc
         $<TARGET_OBJECTS:build_version>)
 
-list(APPEND SOURCE
+list(APPEND SOURCES
   utilities/transactions/lock/range/range_tree/lib/locktree/concurrent_tree.cc
   utilities/transactions/lock/range/range_tree/lib/locktree/keyrange.cc
   utilities/transactions/lock/range/range_tree/lib/locktree/lock_request.cc
@@ -1225,6 +1227,7 @@ if(WITH_TESTS)
         utilities/transactions/lock/point/point_lock_manager_test.cc
         utilities/transactions/write_prepared_transaction_test.cc
         utilities/transactions/write_unprepared_transaction_test.cc
+        utilities/transactions/lock/range/range_locking_test.cc
         utilities/ttl/ttl_test.cc
         utilities/write_batch_with_index/write_batch_with_index_test.cc
     )

Makefile

@@ -558,6 +558,7 @@ PARALLEL_TEST = \
 	table_test \
 	transaction_test \
 	point_lock_manager_test \
+	range_locking_test \
 	write_prepared_transaction_test \
 	write_unprepared_transaction_test \
 
@@ -1936,6 +1937,9 @@ blob_db_test: $(OBJ_DIR)/utilities/blob_db/blob_db_test.o $(TEST_LIBRARY) $(LIBR
 repeatable_thread_test: $(OBJ_DIR)/util/repeatable_thread_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 
+range_locking_test: utilities/transactions/lock/range/range_locking_test.o $(TEST_LIBRARY) $(LIBRARY)
+	$(AM_LINK)
+
 range_tombstone_fragmenter_test: $(OBJ_DIR)/db/range_tombstone_fragmenter_test.o $(TEST_LIBRARY) $(LIBRARY)
 	$(AM_LINK)
 

TARGETS

@@ -400,6 +400,8 @@ cpp_library(
         "utilities/transactions/lock/range/range_tree/lib/standalone_port.cc",
         "utilities/transactions/lock/range/range_tree/lib/util/dbt.cc",
         "utilities/transactions/lock/range/range_tree/lib/util/memarena.cc",
+        "utilities/transactions/lock/range/range_tree/range_tree_lock_manager.cc",
+        "utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.cc",
         "utilities/transactions/optimistic_transaction.cc",
         "utilities/transactions/optimistic_transaction_db_impl.cc",
         "utilities/transactions/pessimistic_transaction.cc",
@@ -702,6 +704,8 @@ cpp_library(
         "utilities/transactions/lock/range/range_tree/lib/standalone_port.cc",
         "utilities/transactions/lock/range/range_tree/lib/util/dbt.cc",
         "utilities/transactions/lock/range/range_tree/lib/util/memarena.cc",
+        "utilities/transactions/lock/range/range_tree/range_tree_lock_manager.cc",
+        "utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.cc",
         "utilities/transactions/optimistic_transaction.cc",
         "utilities/transactions/optimistic_transaction_db_impl.cc",
         "utilities/transactions/pessimistic_transaction.cc",
@@ -1800,6 +1804,13 @@ ROCKS_TESTS = [
         [],
         [],
     ],
+    [
+        "range_locking_test",
+        "utilities/transactions/lock/range/range_locking_test.cc",
+        "parallel",
+        [],
+        [],
+    ],
     [
         "range_tombstone_fragmenter_test",
         "db/range_tombstone_fragmenter_test.cc",

include/rocksdb/utilities/transaction_db.h

@@ -86,7 +86,11 @@ struct RangeDeadlockPath {
 // RocksDB
 class RangeLockManagerHandle : public LockManagerHandle {
  public:
-  // Total amount of lock memory to use (per column family)
+  // Set total amount of lock memory to use.
+  //
+  //  @return 0 Ok
+  //  @return EDOM Failed to set because currently using more memory than
+  //        specified
   virtual int SetMaxLockMemory(size_t max_lock_memory) = 0;
   virtual size_t GetMaxLockMemory() = 0;
 

src.mk

@@ -267,6 +267,8 @@ LIB_SOURCES =                                                   \
   utilities/transactions/lock/range/range_tree/lib/standalone_port.cc          \
   utilities/transactions/lock/range/range_tree/lib/util/dbt.cc                 \
   utilities/transactions/lock/range/range_tree/lib/util/memarena.cc            \
+  utilities/transactions/lock/range/range_tree/range_tree_lock_manager.cc      \
+  utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.cc      \
   utilities/transactions/optimistic_transaction.cc              \
   utilities/transactions/optimistic_transaction_db_impl.cc      \
   utilities/transactions/pessimistic_transaction.cc             \
@@ -536,6 +538,7 @@ TEST_MAIN_SOURCES =                                                     \
   utilities/simulator_cache/sim_cache_test.cc                           \
   utilities/table_properties_collectors/compact_on_deletion_collector_test.cc  \
   utilities/transactions/optimistic_transaction_test.cc                 \
+  utilities/transactions/lock/range/range_locking_test.cc               \
   utilities/transactions/transaction_test.cc                            \
   utilities/transactions/lock/point/point_lock_manager_test.cc          \
   utilities/transactions/write_prepared_transaction_test.cc             \

utilities/transactions/lock/point/point_lock_manager_test.h

@@ -273,4 +273,47 @@ TEST_P(AnyLockManagerTest, Deadlock) {
   delete txn1;
 }
 
+TEST_P(AnyLockManagerTest, GetWaitingTxns_MultipleTxns) {
+  MockColumnFamilyHandle cf(1);
+  locker_->AddColumnFamily(&cf);
+
+  auto txn1 = NewTxn();
+  ASSERT_OK(locker_->TryLock(txn1, 1, "k", env_, false));
+
+  auto txn2 = NewTxn();
+  ASSERT_OK(locker_->TryLock(txn2, 1, "k", env_, false));
+
+  auto txn3 = NewTxn();
+  txn3->SetLockTimeout(10000);
+  port::Thread t1 = BlockUntilWaitingTxn(wait_sync_point_name_, [&]() {
+    ASSERT_OK(locker_->TryLock(txn3, 1, "k", env_, true));
+    locker_->UnLock(txn3, 1, "k", env_);
+  });
+
+  // Ok, now txn3 is waiting for lock on "k", which is owned by two
+  // transactions. Check that GetWaitingTxns reports this correctly
+  uint32_t wait_cf_id;
+  std::string wait_key;
+  auto waiters = txn3->GetWaitingTxns(&wait_cf_id, &wait_key);
+
+  ASSERT_EQ(wait_cf_id, 1u);
+  ASSERT_EQ(wait_key, "k");
+  ASSERT_EQ(waiters.size(), 2);
+  bool waits_correct =
+      (waiters[0] == txn1->GetID() && waiters[1] == txn2->GetID()) ||
+      (waiters[1] == txn1->GetID() && waiters[0] == txn2->GetID());
+  ASSERT_EQ(waits_correct, true);
+
+  // Release locks so txn3 can proceed with execution
+  locker_->UnLock(txn1, 1, "k", env_);
+  locker_->UnLock(txn2, 1, "k", env_);
+
+  // Wait until txn3 finishes
+  t1.join();
+
+  delete txn1;
+  delete txn2;
+  delete txn3;
+}
+
 }  // namespace ROCKSDB_NAMESPACE

utilities/transactions/lock/range/range_locking_test.cc

@@ -0,0 +1,304 @@
+//  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).
+
+#ifndef ROCKSDB_LITE
+#ifndef OS_WIN
+
+#include <algorithm>
+#include <functional>
+#include <string>
+#include <thread>
+
+#include "db/db_impl/db_impl.h"
+#include "port/port.h"
+#include "rocksdb/db.h"
+#include "rocksdb/options.h"
+#include "rocksdb/perf_context.h"
+#include "rocksdb/utilities/transaction.h"
+#include "rocksdb/utilities/transaction_db.h"
+#include "utilities/transactions/lock/point/point_lock_manager_test.h"
+#include "utilities/transactions/pessimistic_transaction_db.h"
+#include "utilities/transactions/transaction_test.h"
+
+using std::string;
+
+namespace ROCKSDB_NAMESPACE {
+
+class RangeLockingTest : public ::testing::Test {
+ public:
+  TransactionDB* db;
+  std::string dbname;
+  Options options;
+
+  std::shared_ptr<RangeLockManagerHandle> range_lock_mgr;
+  TransactionDBOptions txn_db_options;
+
+  RangeLockingTest() : db(nullptr) {
+    options.create_if_missing = true;
+    dbname = test::PerThreadDBPath("range_locking_testdb");
+
+    DestroyDB(dbname, options);
+
+    range_lock_mgr.reset(NewRangeLockManager(nullptr));
+    txn_db_options.lock_mgr_handle = range_lock_mgr;
+
+    auto s = TransactionDB::Open(options, txn_db_options, dbname, &db);
+    assert(s.ok());
+  }
+
+  ~RangeLockingTest() {
+    delete db;
+    db = nullptr;
+    // This is to skip the assert statement in FaultInjectionTestEnv. There
+    // seems to be a bug in btrfs that the makes readdir return recently
+    // unlink-ed files. By using the default fs we simply ignore errors resulted
+    // from attempting to delete such files in DestroyDB.
+    DestroyDB(dbname, options);
+  }
+
+  PessimisticTransaction* NewTxn(
+      TransactionOptions txn_opt = TransactionOptions()) {
+    Transaction* txn = db->BeginTransaction(WriteOptions(), txn_opt);
+    return reinterpret_cast<PessimisticTransaction*>(txn);
+  }
+};
+
+// TODO: set a smaller lock wait timeout so that the test runs faster.
+TEST_F(RangeLockingTest, BasicRangeLocking) {
+  WriteOptions write_options;
+  TransactionOptions txn_options;
+  std::string value;
+  ReadOptions read_options;
+  auto cf = db->DefaultColumnFamily();
+
+  Transaction* txn0 = db->BeginTransaction(write_options, txn_options);
+  Transaction* txn1 = db->BeginTransaction(write_options, txn_options);
+
+  // Get a range lock
+  ASSERT_OK(txn0->GetRangeLock(cf, Endpoint("a"), Endpoint("c")));
+
+  // Check that range Lock inhibits an overlapping range lock
+  {
+    auto s = txn1->GetRangeLock(cf, Endpoint("b"), Endpoint("z"));
+    ASSERT_TRUE(s.IsTimedOut());
+  }
+
+  // Check that range Lock inhibits an overlapping point lock
+  {
+    auto s = txn1->GetForUpdate(read_options, cf, Slice("b"), &value);
+    ASSERT_TRUE(s.IsTimedOut());
+  }
+
+  // Get a point lock, check that it inhibits range locks
+  ASSERT_OK(txn0->Put(cf, Slice("n"), Slice("value")));
+  {
+    auto s = txn1->GetRangeLock(cf, Endpoint("m"), Endpoint("p"));
+    ASSERT_TRUE(s.IsTimedOut());
+  }
+
+  ASSERT_OK(txn0->Commit());
+  txn1->Rollback();
+
+  delete txn0;
+  delete txn1;
+}
+
+TEST_F(RangeLockingTest, MyRocksLikeUpdate) {
+  WriteOptions write_options;
+  TransactionOptions txn_options;
+  Transaction* txn0 = db->BeginTransaction(write_options, txn_options);
+  auto cf = db->DefaultColumnFamily();
+  Status s;
+
+  // Get a range lock for the range we are about to update
+  ASSERT_OK(txn0->GetRangeLock(cf, Endpoint("a"), Endpoint("c")));
+
+  bool try_range_lock_called = false;
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "RangeTreeLockManager::TryRangeLock:enter",
+      [&](void* /*arg*/) { try_range_lock_called = true; });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  // For performance reasons, the following must NOT call lock_mgr->TryLock():
+  // We verify that by checking the value of try_range_lock_called.
+  ASSERT_OK(txn0->Put(cf, Slice("b"), Slice("value"),
+                      /*assume_tracked=*/true));
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->ClearAllCallBacks();
+  ASSERT_FALSE(try_range_lock_called);
+
+  txn0->Rollback();
+
+  delete txn0;
+}
+
+TEST_F(RangeLockingTest, SnapshotValidation) {
+  Status s;
+  Slice key_slice = Slice("k");
+  ColumnFamilyHandle* cfh = db->DefaultColumnFamily();
+
+  auto txn0 = NewTxn();
+  txn0->Put(key_slice, Slice("initial"));
+  txn0->Commit();
+
+  // txn1
+  auto txn1 = NewTxn();
+  txn1->SetSnapshot();
+  std::string val1;
+  ASSERT_OK(txn1->Get(ReadOptions(), cfh, key_slice, &val1));
+  ASSERT_EQ(val1, "initial");
+  val1 = val1 + std::string("-txn1");
+
+  ASSERT_OK(txn1->Put(cfh, key_slice, Slice(val1)));
+
+  // txn2
+  auto txn2 = NewTxn();
+  txn2->SetSnapshot();
+  std::string val2;
+  // This will see the original value as nothing is committed
+  // This is also Get, so it is doesn't acquire any locks.
+  ASSERT_OK(txn2->Get(ReadOptions(), cfh, key_slice, &val2));
+  ASSERT_EQ(val2, "initial");
+
+  // txn1
+  ASSERT_OK(txn1->Commit());
+
+  // txn2
+  val2 = val2 + std::string("-txn2");
+  // Now, this call should do Snapshot Validation and fail:
+  s = txn2->Put(cfh, key_slice, Slice(val2));
+  ASSERT_TRUE(s.IsBusy());
+
+  ASSERT_OK(txn2->Commit());
+
+  delete txn0;
+  delete txn1;
+  delete txn2;
+}
+
+TEST_F(RangeLockingTest, MultipleTrxLockStatusData) {
+  WriteOptions write_options;
+  TransactionOptions txn_options;
+  auto cf = db->DefaultColumnFamily();
+
+  Transaction* txn0 = db->BeginTransaction(write_options, txn_options);
+  Transaction* txn1 = db->BeginTransaction(write_options, txn_options);
+
+  // Get a range lock
+  ASSERT_OK(txn0->GetRangeLock(cf, Endpoint("z"), Endpoint("z")));
+  ASSERT_OK(txn1->GetRangeLock(cf, Endpoint("b"), Endpoint("e")));
+
+  auto s = range_lock_mgr->GetRangeLockStatusData();
+  ASSERT_EQ(s.size(), 2);
+  for (auto it = s.begin(); it != s.end(); ++it) {
+    ASSERT_EQ(it->first, cf->GetID());
+    auto val = it->second;
+    ASSERT_FALSE(val.start.inf_suffix);
+    ASSERT_FALSE(val.end.inf_suffix);
+    ASSERT_TRUE(val.exclusive);
+    ASSERT_EQ(val.ids.size(), 1);
+    if (val.ids[0] == txn0->GetID()) {
+      ASSERT_EQ(val.start.slice, "z");
+      ASSERT_EQ(val.end.slice, "z");
+    } else if (val.ids[0] == txn1->GetID()) {
+      ASSERT_EQ(val.start.slice, "b");
+      ASSERT_EQ(val.end.slice, "e");
+    } else {
+      FAIL();  // Unknown transaction ID.
+    }
+  }
+
+  delete txn0;
+  delete txn1;
+}
+
+#if defined(__has_feature)
+#if __has_feature(thread_sanitizer)
+#define SKIP_LOCK_ESCALATION_TEST 1
+#endif
+#endif
+
+#ifndef SKIP_LOCK_ESCALATION_TEST
+TEST_F(RangeLockingTest, BasicLockEscalation) {
+  auto cf = db->DefaultColumnFamily();
+
+  auto counters = range_lock_mgr->GetStatus();
+
+  // Initially not using any lock memory
+  ASSERT_EQ(counters.current_lock_memory, 0);
+  ASSERT_EQ(counters.escalation_count, 0);
+
+  ASSERT_EQ(0, range_lock_mgr->SetMaxLockMemory(2000));
+
+  // Insert until we see lock escalations
+  auto txn = NewTxn();
+
+  // Get the locks until we hit an escalation
+  for (int i = 0; i < 2020; i++) {
+    char buf[32];
+    snprintf(buf, sizeof(buf) - 1, "%08d", i);
+    ASSERT_OK(txn->GetRangeLock(cf, Endpoint(buf), Endpoint(buf)));
+  }
+  counters = range_lock_mgr->GetStatus();
+  ASSERT_GT(counters.escalation_count, 0);
+  ASSERT_LE(counters.current_lock_memory, 2000);
+
+  delete txn;
+}
+#endif
+
+void PointLockManagerTestExternalSetup(PointLockManagerTest* self) {
+  self->env_ = Env::Default();
+  self->db_dir_ = test::PerThreadDBPath("point_lock_manager_test");
+  ASSERT_OK(self->env_->CreateDir(self->db_dir_));
+
+  Options opt;
+  opt.create_if_missing = true;
+  TransactionDBOptions txn_opt;
+  txn_opt.transaction_lock_timeout = 0;
+
+  auto mutex_factory = std::make_shared<TransactionDBMutexFactoryImpl>();
+  self->locker_.reset(NewRangeLockManager(mutex_factory)->getLockManager());
+  std::shared_ptr<RangeLockManagerHandle> range_lock_mgr =
+      std::dynamic_pointer_cast<RangeLockManagerHandle>(self->locker_);
+  txn_opt.lock_mgr_handle = range_lock_mgr;
+
+  ASSERT_OK(TransactionDB::Open(opt, txn_opt, self->db_dir_, &self->db_));
+  self->wait_sync_point_name_ = "RangeTreeLockManager::TryRangeLock:WaitingTxn";
+}
+
+INSTANTIATE_TEST_CASE_P(RangeLockManager, AnyLockManagerTest,
+                        ::testing::Values(PointLockManagerTestExternalSetup));
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
+#else  // OS_WIN
+
+#include <stdio.h>
+int main(int /*argc*/, char** /*argv*/) {
+  fprintf(stderr, "skipped as Range Locking is not supported on Windows\n");
+  return 0;
+}
+
+#endif  // OS_WIN
+
+#else
+#include <stdio.h>
+
+int main(int /*argc*/, char** /*argv*/) {
+  fprintf(stderr,
+          "skipped as transactions are not supported in rocksdb_lite\n");
+  return 0;
+}
+
+#endif  // ROCKSDB_LITE

utilities/transactions/lock/range/range_tree/TODO

@@ -1 +0,0 @@
-Implement LockTracker and LockManager for range lock with range tree.

utilities/transactions/lock/range/range_tree/lib/locktree/lock_request.cc

@@ -1,5 +1,5 @@
 /* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
-// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
+// vim: ft=cpp:expandtab:ts=8:sw=2:softtabstop=2:
 #ifndef ROCKSDB_LITE
 #ifndef OS_WIN
 #ident "$Id$"
@@ -240,7 +240,7 @@ int lock_request::wait(uint64_t wait_time_ms) {
 
 int lock_request::wait(uint64_t wait_time_ms, uint64_t killed_time_ms,
                        int (*killed_callback)(void),
-                       void (*lock_wait_callback)(void *, TXNID, TXNID),
+                       void (*lock_wait_callback)(void *, lock_wait_infos *),
                        void *callback_arg) {
   uint64_t t_now = toku_current_time_microsec();
   uint64_t t_start = t_now;
@@ -250,13 +250,11 @@ int lock_request::wait(uint64_t wait_time_ms, uint64_t killed_time_ms,
 
   // check again, this time locking out other retry calls
   if (m_state == state::PENDING) {
-    GrowableArray<TXNID> conflicts_collector;
+    lock_wait_infos conflicts_collector;
-    conflicts_collector.init();
     retry(&conflicts_collector);
     if (m_state == state::PENDING) {
       report_waits(&conflicts_collector, lock_wait_callback, callback_arg);
     }
-    conflicts_collector.deinit();
   }
 
   while (m_state == state::PENDING) {
@@ -325,7 +323,7 @@ TXNID lock_request::get_conflicting_txnid(void) const {
   return m_conflicting_txnid;
 }
 
-int lock_request::retry(GrowableArray<TXNID> *conflicts_collector) {
+int lock_request::retry(lock_wait_infos *conflicts_collector) {
   invariant(m_state == state::PENDING);
   int r;
   txnid_set conflicts;
@@ -356,7 +354,7 @@ int lock_request::retry(GrowableArray<TXNID> *conflicts_collector) {
 }
 
 void lock_request::retry_all_lock_requests(
-    locktree *lt, void (*lock_wait_callback)(void *, TXNID, TXNID),
+    locktree *lt, void (*lock_wait_callback)(void *, lock_wait_infos *),
     void *callback_arg, void (*after_retry_all_test_callback)(void)) {
   lt_lock_request_info *info = lt->get_lock_request_info();
 
@@ -370,8 +368,7 @@ void lock_request::retry_all_lock_requests(
 
   toku_mutex_lock(&info->retry_mutex);
 
-  GrowableArray<TXNID> conflicts_collector;
+  lock_wait_infos conflicts_collector;
-  conflicts_collector.init();
 
   // here is the group retry algorithm.
   // get the latest retry_want count and use it as the generation number of
@@ -398,11 +395,10 @@ void lock_request::retry_all_lock_requests(
   toku_mutex_unlock(&info->retry_mutex);
 
   report_waits(&conflicts_collector, lock_wait_callback, callback_arg);
-  conflicts_collector.deinit();
 }
 
-void lock_request::retry_all_lock_requests_info(
+void lock_request::retry_all_lock_requests_info(lt_lock_request_info *info,
-    lt_lock_request_info *info, GrowableArray<TXNID> *collector) {
+                                                lock_wait_infos *collector) {
   toku_external_mutex_lock(&info->mutex);
   // retry all of the pending lock requests.
   for (uint32_t i = 0; i < info->pending_lock_requests.size();) {
@@ -425,26 +421,20 @@ void lock_request::retry_all_lock_requests_info(
   toku_external_mutex_unlock(&info->mutex);
 }
 
-void lock_request::add_conflicts_to_waits(
+void lock_request::add_conflicts_to_waits(txnid_set *conflicts,
-    txnid_set *conflicts, GrowableArray<TXNID> *wait_conflicts) {
+                                          lock_wait_infos *wait_conflicts) {
+  wait_conflicts->push_back({m_lt, get_txnid(), m_extra, {}});
   uint32_t num_conflicts = conflicts->size();
   for (uint32_t i = 0; i < num_conflicts; i++) {
-    wait_conflicts->push(m_txnid);
+    wait_conflicts->back().waitees.push_back(conflicts->get(i));
-    wait_conflicts->push(conflicts->get(i));
   }
 }
 
-void lock_request::report_waits(GrowableArray<TXNID> *wait_conflicts,
+void lock_request::report_waits(lock_wait_infos *wait_conflicts,
-                                void (*lock_wait_callback)(void *, TXNID,
+                                void (*lock_wait_callback)(void *,
-                                                           TXNID),
+                                                           lock_wait_infos *),
                                 void *callback_arg) {
-  if (!lock_wait_callback) return;
+  if (lock_wait_callback) (*lock_wait_callback)(callback_arg, wait_conflicts);
-  size_t num_conflicts = wait_conflicts->get_size();
-  for (size_t i = 0; i < num_conflicts; i += 2) {
-    TXNID blocked_txnid = wait_conflicts->fetch_unchecked(i);
-    TXNID blocking_txnid = wait_conflicts->fetch_unchecked(i + 1);
-    (*lock_wait_callback)(callback_arg, blocked_txnid, blocking_txnid);
-  }
 }
 
 void *lock_request::get_extra(void) const { return m_extra; }

utilities/transactions/lock/range/range_tree/lib/locktree/lock_request.h

@@ -1,5 +1,5 @@
 /* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
-// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
+// vim: ft=cpp:expandtab:ts=8:sw=2:softtabstop=2:
 #ident "$Id$"
 /*======
 This file is part of PerconaFT.
@@ -62,6 +62,18 @@ Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved.
 
 namespace toku {
 
+// Information about a lock wait
+struct lock_wait_info {
+  locktree *ltree;  // the tree where wait happens
+  TXNID waiter;     // the waiting transaction
+  void *m_extra;    // lock_request's m_extra
+
+  // The transactions that are waited for.
+  std::vector<TXNID> waitees;
+};
+
+typedef std::vector<lock_wait_info> lock_wait_infos;
+
 // A lock request contains the db, the key range, the lock type, and
 // the transaction id that describes a potential row range lock.
 //
@@ -101,7 +113,7 @@ class lock_request {
   int wait(uint64_t wait_time_ms);
   int wait(uint64_t wait_time_ms, uint64_t killed_time_ms,
            int (*killed_callback)(void),
-           void (*lock_wait_callback)(void *, TXNID, TXNID) = nullptr,
+           void (*lock_wait_callback)(void *, lock_wait_infos *) = nullptr,
            void *callback_arg = nullptr);
 
   // return: left end-point of the lock range
@@ -124,11 +136,12 @@ class lock_request {
   //         up.
   //         The rest remain pending.
   static void retry_all_lock_requests(
-      locktree *lt, void (*lock_wait_callback)(void *, TXNID, TXNID) = nullptr,
+      locktree *lt,
+      void (*lock_wait_callback)(void *, lock_wait_infos *) = nullptr,
       void *callback_arg = nullptr,
       void (*after_retry_test_callback)(void) = nullptr);
   static void retry_all_lock_requests_info(lt_lock_request_info *info,
-                                           GrowableArray<TXNID> *collector);
+                                           lock_wait_infos *collector);
 
   void set_start_test_callback(void (*f)(void));
   void set_start_before_pending_test_callback(void (*f)(void));
@@ -181,7 +194,7 @@ class lock_request {
 
   // effect: tries again to acquire the lock described by this lock request
   // returns: 0 if retrying the request succeeded and is now complete
-  int retry(GrowableArray<TXNID> *conflict_collector);
+  int retry(lock_wait_infos *collector);
 
   void complete(int complete_r);
 
@@ -216,11 +229,12 @@ class lock_request {
   static int find_by_txnid(lock_request *const &request, const TXNID &txnid);
 
   // Report list of conflicts to lock wait callback.
-  static void report_waits(GrowableArray<TXNID> *wait_conflicts,
+  static void report_waits(lock_wait_infos *wait_conflicts,
-                           void (*lock_wait_callback)(void *, TXNID, TXNID),
+                           void (*lock_wait_callback)(void *,
+                                                      lock_wait_infos *),
                            void *callback_arg);
   void add_conflicts_to_waits(txnid_set *conflicts,
-                              GrowableArray<TXNID> *wait_conflicts);
+                              lock_wait_infos *wait_conflicts);
 
   void (*m_start_test_callback)(void);
   void (*m_start_before_pending_test_callback)(void);

utilities/transactions/lock/range/range_tree/lib/locktree/locktree.cc

@@ -1,5 +1,5 @@
 /* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
-// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
+// vim: ft=cpp:expandtab:ts=8:sw=2:softtabstop=2:
 #ifndef ROCKSDB_LITE
 #ifndef OS_WIN
 #ident "$Id$"
@@ -186,7 +186,13 @@ static bool determine_conflicting_txnids(
     const TXNID other_txnid = lock.txnid;
     if (other_txnid != txnid) {
       if (conflicts) {
-        conflicts->add(other_txnid);
+        if (other_txnid == TXNID_SHARED) {
+          for (TXNID shared_id : *lock.owners) {
+            conflicts->add(shared_id);
+          }
+        } else {
+          conflicts->add(other_txnid);
+        }
       }
       conflicts_exist = true;
     }

utilities/transactions/lock/range/range_tree/range_tree_lock_manager.cc

@@ -0,0 +1,479 @@
+//  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).
+
+#ifndef ROCKSDB_LITE
+#ifndef OS_WIN
+
+#include "utilities/transactions/lock/range/range_tree/range_tree_lock_manager.h"
+
+#include <algorithm>
+#include <cinttypes>
+#include <mutex>
+
+#include "monitoring/perf_context_imp.h"
+#include "rocksdb/slice.h"
+#include "rocksdb/utilities/transaction_db_mutex.h"
+#include "test_util/sync_point.h"
+#include "util/cast_util.h"
+#include "util/hash.h"
+#include "util/thread_local.h"
+#include "utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.h"
+#include "utilities/transactions/pessimistic_transaction_db.h"
+#include "utilities/transactions/transaction_db_mutex_impl.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+RangeLockManagerHandle* NewRangeLockManager(
+    std::shared_ptr<TransactionDBMutexFactory> mutex_factory) {
+  std::shared_ptr<TransactionDBMutexFactory> use_factory;
+
+  if (mutex_factory) {
+    use_factory = mutex_factory;
+  } else {
+    use_factory.reset(new TransactionDBMutexFactoryImpl());
+  }
+  return new RangeTreeLockManager(use_factory);
+}
+
+static const char SUFFIX_INFIMUM = 0x0;
+static const char SUFFIX_SUPREMUM = 0x1;
+
+// Convert Endpoint into an internal format used for storing it in locktree
+// (DBT structure is used for passing endpoints to locktree and getting back)
+void serialize_endpoint(const Endpoint& endp, std::string* buf) {
+  buf->push_back(endp.inf_suffix ? SUFFIX_SUPREMUM : SUFFIX_INFIMUM);
+  buf->append(endp.slice.data(), endp.slice.size());
+}
+
+// Decode the endpoint from the format it is stored in the locktree (DBT) to
+// one used outside (EndpointWithString)
+void deserialize_endpoint(const DBT* dbt, EndpointWithString* endp) {
+  assert(dbt->size >= 1);
+  const char* dbt_data = (const char*)dbt->data;
+  char suffix = dbt_data[0];
+  assert(suffix == SUFFIX_INFIMUM || suffix == SUFFIX_SUPREMUM);
+  endp->inf_suffix = (suffix == SUFFIX_SUPREMUM);
+  endp->slice.assign(dbt_data + 1, dbt->size - 1);
+}
+
+// Get a range lock on [start_key; end_key] range
+Status RangeTreeLockManager::TryLock(PessimisticTransaction* txn,
+                                     uint32_t column_family_id,
+                                     const Endpoint& start_endp,
+                                     const Endpoint& end_endp, Env*,
+                                     bool exclusive) {
+  toku::lock_request request;
+  request.create(mutex_factory_);
+  DBT start_key_dbt, end_key_dbt;
+
+  TEST_SYNC_POINT("RangeTreeLockManager::TryRangeLock:enter");
+  std::string start_key;
+  std::string end_key;
+  serialize_endpoint(start_endp, &start_key);
+  serialize_endpoint(end_endp, &end_key);
+
+  toku_fill_dbt(&start_key_dbt, start_key.data(), start_key.size());
+  toku_fill_dbt(&end_key_dbt, end_key.data(), end_key.size());
+
+  auto lt = GetLockTreeForCF(column_family_id);
+
+  // Put the key waited on into request's m_extra. See
+  // wait_callback_for_locktree for details.
+  std::string wait_key(start_endp.slice.data(), start_endp.slice.size());
+
+  request.set(lt.get(), (TXNID)txn, &start_key_dbt, &end_key_dbt,
+              exclusive ? toku::lock_request::WRITE : toku::lock_request::READ,
+              false /* not a big txn */, &wait_key);
+
+  // This is for "periodically wake up and check if the wait is killed" feature
+  // which we are not using.
+  uint64_t killed_time_msec = 0;
+  uint64_t wait_time_msec = txn->GetLockTimeout();
+
+  if (wait_time_msec == static_cast<uint64_t>(-1)) {
+    // The transaction has no wait timeout. lock_request::wait doesn't support
+    // this, it needs a number of milliseconds to wait. Pass it one year to
+    // be safe.
+    wait_time_msec = uint64_t(1000) * 60 * 60 * 24 * 365;
+  } else {
+    // convert microseconds to milliseconds
+    wait_time_msec = (wait_time_msec + 500) / 1000;
+  }
+
+  std::vector<RangeDeadlockInfo> di_path;
+  request.m_deadlock_cb = [&](TXNID txnid, bool is_exclusive,
+                              const DBT* start_dbt, const DBT* end_dbt) {
+    EndpointWithString start;
+    EndpointWithString end;
+    deserialize_endpoint(start_dbt, &start);
+    deserialize_endpoint(end_dbt, &end);
+
+    di_path.push_back({((PessimisticTransaction*)txnid)->GetID(),
+                       column_family_id, is_exclusive, std::move(start),
+                       std::move(end)});
+  };
+
+  request.start();
+
+  const int r = request.wait(wait_time_msec, killed_time_msec,
+                             nullptr,  // killed_callback
+                             wait_callback_for_locktree, nullptr);
+
+  // Inform the txn that we are no longer waiting:
+  txn->ClearWaitingTxn();
+
+  request.destroy();
+  switch (r) {
+    case 0:
+      break;  // fall through
+    case DB_LOCK_NOTGRANTED:
+      return Status::TimedOut(Status::SubCode::kLockTimeout);
+    case TOKUDB_OUT_OF_LOCKS:
+      return Status::Busy(Status::SubCode::kLockLimit);
+    case DB_LOCK_DEADLOCK: {
+      std::reverse(di_path.begin(), di_path.end());
+      dlock_buffer_.AddNewPath(
+          RangeDeadlockPath(di_path, request.get_start_time()));
+      return Status::Busy(Status::SubCode::kDeadlock);
+    }
+    default:
+      assert(0);
+      return Status::Busy(Status::SubCode::kLockLimit);
+  }
+
+  return Status::OK();
+}
+
+// Wait callback that locktree library will call to inform us about
+// the lock waits that are in progress.
+void wait_callback_for_locktree(void*, lock_wait_infos* infos) {
+  for (auto wait_info : *infos) {
+    auto txn = (PessimisticTransaction*)wait_info.waiter;
+    auto cf_id = (ColumnFamilyId)wait_info.ltree->get_dict_id().dictid;
+
+    autovector<TransactionID> waitee_ids;
+    for (auto waitee : wait_info.waitees) {
+      waitee_ids.push_back(((PessimisticTransaction*)waitee)->GetID());
+    }
+    txn->SetWaitingTxn(waitee_ids, cf_id, (std::string*)wait_info.m_extra);
+  }
+
+  // Here we can assume that the locktree code will now wait for some lock
+  TEST_SYNC_POINT("RangeTreeLockManager::TryRangeLock:WaitingTxn");
+}
+
+void RangeTreeLockManager::UnLock(PessimisticTransaction* txn,
+                                  ColumnFamilyId column_family_id,
+                                  const std::string& key, Env*) {
+  auto locktree = GetLockTreeForCF(column_family_id);
+  std::string endp_image;
+  serialize_endpoint({key.data(), key.size(), false}, &endp_image);
+
+  DBT key_dbt;
+  toku_fill_dbt(&key_dbt, endp_image.data(), endp_image.size());
+
+  toku::range_buffer range_buf;
+  range_buf.create();
+  range_buf.append(&key_dbt, &key_dbt);
+
+  locktree->release_locks((TXNID)txn, &range_buf);
+  range_buf.destroy();
+
+  toku::lock_request::retry_all_lock_requests(
+      locktree.get(), wait_callback_for_locktree, nullptr);
+}
+
+void RangeTreeLockManager::UnLock(PessimisticTransaction* txn,
+                                  const LockTracker& tracker, Env*) {
+  const RangeTreeLockTracker* range_tracker =
+      static_cast<const RangeTreeLockTracker*>(&tracker);
+
+  RangeTreeLockTracker* range_trx_tracker =
+      static_cast<RangeTreeLockTracker*>(&txn->GetTrackedLocks());
+  bool all_keys = (range_trx_tracker == range_tracker);
+
+  // tracked_locks_->range_list may hold nullptr if the transaction has never
+  // acquired any locks.
+  ((RangeTreeLockTracker*)range_tracker)->ReleaseLocks(this, txn, all_keys);
+}
+
+int RangeTreeLockManager::CompareDbtEndpoints(void* arg, const DBT* a_key,
+                                              const DBT* b_key) {
+  const char* a = (const char*)a_key->data;
+  const char* b = (const char*)b_key->data;
+
+  size_t a_len = a_key->size;
+  size_t b_len = b_key->size;
+
+  size_t min_len = std::min(a_len, b_len);
+
+  // Compare the values. The first byte encodes the endpoint type, its value
+  // is either SUFFIX_INFIMUM or SUFFIX_SUPREMUM.
+  Comparator* cmp = (Comparator*)arg;
+  int res = cmp->Compare(Slice(a + 1, min_len - 1), Slice(b + 1, min_len - 1));
+  if (!res) {
+    if (b_len > min_len) {
+      // a is shorter;
+      if (a[0] == SUFFIX_INFIMUM) {
+        return -1;  //"a is smaller"
+      } else {
+        // a is considered padded with 0xFF:FF:FF:FF...
+        return 1;  // "a" is bigger
+      }
+    } else if (a_len > min_len) {
+      // the opposite of the above: b is shorter.
+      if (b[0] == SUFFIX_INFIMUM) {
+        return 1;  //"b is smaller"
+      } else {
+        // b is considered padded with 0xFF:FF:FF:FF...
+        return -1;  // "b" is bigger
+      }
+    } else {
+      // the lengths are equal (and the key values, too)
+      if (a[0] < b[0]) {
+        return -1;
+      } else if (a[0] > b[0]) {
+        return 1;
+      } else {
+        return 0;
+      }
+    }
+  } else {
+    return res;
+  }
+}
+
+namespace {
+void UnrefLockTreeMapsCache(void* ptr) {
+  // Called when a thread exits or a ThreadLocalPtr gets destroyed.
+  auto lock_tree_map_cache = static_cast<
+      std::unordered_map<ColumnFamilyId, std::shared_ptr<locktree>>*>(ptr);
+  delete lock_tree_map_cache;
+}
+}  // anonymous namespace
+
+RangeTreeLockManager::RangeTreeLockManager(
+    std::shared_ptr<TransactionDBMutexFactory> mutex_factory)
+    : mutex_factory_(mutex_factory),
+      ltree_lookup_cache_(new ThreadLocalPtr(&UnrefLockTreeMapsCache)),
+      dlock_buffer_(10) {
+  ltm_.create(on_create, on_destroy, on_escalate, nullptr, mutex_factory_);
+}
+
+void RangeTreeLockManager::SetRangeDeadlockInfoBufferSize(
+    uint32_t target_size) {
+  dlock_buffer_.Resize(target_size);
+}
+
+void RangeTreeLockManager::Resize(uint32_t target_size) {
+  SetRangeDeadlockInfoBufferSize(target_size);
+}
+
+std::vector<RangeDeadlockPath>
+RangeTreeLockManager::GetRangeDeadlockInfoBuffer() {
+  return dlock_buffer_.PrepareBuffer();
+}
+
+std::vector<DeadlockPath> RangeTreeLockManager::GetDeadlockInfoBuffer() {
+  std::vector<DeadlockPath> res;
+  std::vector<RangeDeadlockPath> data = GetRangeDeadlockInfoBuffer();
+  // report left endpoints
+  for (auto it = data.begin(); it != data.end(); ++it) {
+    std::vector<DeadlockInfo> path;
+
+    for (auto it2 = it->path.begin(); it2 != it->path.end(); ++it2) {
+      path.push_back(
+          {it2->m_txn_id, it2->m_cf_id, it2->m_exclusive, it2->m_start.slice});
+    }
+    res.push_back(DeadlockPath(path, it->deadlock_time));
+  }
+  return res;
+}
+
+// @brief  Lock Escalation Callback function
+//
+// @param txnid   Transaction whose locks got escalated
+// @param lt      Lock Tree where escalation is happening
+// @param buffer  Escalation result: list of locks that this transaction now
+//                owns in this lock tree.
+// @param void*   Callback context
+void RangeTreeLockManager::on_escalate(TXNID txnid, const locktree* lt,
+                                       const range_buffer& buffer, void*) {
+  auto txn = (PessimisticTransaction*)txnid;
+  ((RangeTreeLockTracker*)&txn->GetTrackedLocks())->ReplaceLocks(lt, buffer);
+}
+
+RangeTreeLockManager::~RangeTreeLockManager() {
+  autovector<void*> local_caches;
+  ltree_lookup_cache_->Scrape(&local_caches, nullptr);
+  for (auto cache : local_caches) {
+    delete static_cast<LockTreeMap*>(cache);
+  }
+  ltree_map_.clear();  // this will call release_lt() for all locktrees
+  ltm_.destroy();
+}
+
+RangeLockManagerHandle::Counters RangeTreeLockManager::GetStatus() {
+  LTM_STATUS_S ltm_status_test;
+  ltm_.get_status(&ltm_status_test);
+  Counters res;
+
+  // Searching status variable by its string name is how Toku's unit tests
+  // do it (why didn't they make LTM_ESCALATION_COUNT constant visible?)
+  // lookup keyname in status
+  for (int i = 0; i < LTM_STATUS_S::LTM_STATUS_NUM_ROWS; i++) {
+    TOKU_ENGINE_STATUS_ROW status = &ltm_status_test.status[i];
+    if (strcmp(status->keyname, "LTM_ESCALATION_COUNT") == 0) {
+      res.escalation_count = status->value.num;
+      continue;
+    }
+    if (strcmp(status->keyname, "LTM_SIZE_CURRENT") == 0) {
+      res.current_lock_memory = status->value.num;
+    }
+  }
+  return res;
+}
+
+std::shared_ptr<locktree> RangeTreeLockManager::MakeLockTreePtr(locktree* lt) {
+  locktree_manager* ltm = &ltm_;
+  return std::shared_ptr<locktree>(lt,
+                                   [ltm](locktree* p) { ltm->release_lt(p); });
+}
+
+void RangeTreeLockManager::AddColumnFamily(const ColumnFamilyHandle* cfh) {
+  uint32_t column_family_id = cfh->GetID();
+
+  InstrumentedMutexLock l(&ltree_map_mutex_);
+  if (ltree_map_.find(column_family_id) == ltree_map_.end()) {
+    DICTIONARY_ID dict_id = {.dictid = column_family_id};
+    toku::comparator cmp;
+    cmp.create(CompareDbtEndpoints, (void*)cfh->GetComparator());
+    toku::locktree* ltree = ltm_.get_lt(dict_id, cmp,
+                                        /* on_create_extra*/ nullptr);
+    // This is ok to because get_lt has copied the comparator:
+    cmp.destroy();
+
+    ltree_map_.insert({column_family_id, MakeLockTreePtr(ltree)});
+  }
+}
+
+void RangeTreeLockManager::RemoveColumnFamily(const ColumnFamilyHandle* cfh) {
+  uint32_t column_family_id = cfh->GetID();
+  // Remove lock_map for this column family.  Since the lock map is stored
+  // as a shared ptr, concurrent transactions can still keep using it
+  // until they release their references to it.
+
+  // TODO what if one drops a column family while transaction(s) still have
+  // locks in it?
+  // locktree uses column family'c Comparator* as the criteria to do tree
+  // ordering. If the comparator is gone, we won't even be able to remove the
+  // elements from the locktree.
+  // A possible solution might be to remove everything right now:
+  //  - wait until everyone traversing the locktree are gone
+  //  - remove everything from the locktree.
+  //  - some transactions may have acquired locks in their LockTracker objects.
+  //    Arrange something so we don't blow up when they try to release them.
+  //  - ...
+  // This use case (drop column family while somebody is using it) doesn't seem
+  // the priority, though.
+
+  {
+    InstrumentedMutexLock l(&ltree_map_mutex_);
+
+    auto lock_maps_iter = ltree_map_.find(column_family_id);
+    assert(lock_maps_iter != ltree_map_.end());
+    ltree_map_.erase(lock_maps_iter);
+  }  // lock_map_mutex_
+
+  autovector<void*> local_caches;
+  ltree_lookup_cache_->Scrape(&local_caches, nullptr);
+  for (auto cache : local_caches) {
+    delete static_cast<LockTreeMap*>(cache);
+  }
+}
+
+std::shared_ptr<locktree> RangeTreeLockManager::GetLockTreeForCF(
+    ColumnFamilyId column_family_id) {
+  // First check thread-local cache
+  if (ltree_lookup_cache_->Get() == nullptr) {
+    ltree_lookup_cache_->Reset(new LockTreeMap());
+  }
+
+  auto ltree_map_cache = static_cast<LockTreeMap*>(ltree_lookup_cache_->Get());
+
+  auto it = ltree_map_cache->find(column_family_id);
+  if (it != ltree_map_cache->end()) {
+    // Found lock map for this column family.
+    return it->second;
+  }
+
+  // Not found in local cache, grab mutex and check shared LockMaps
+  InstrumentedMutexLock l(&ltree_map_mutex_);
+
+  it = ltree_map_.find(column_family_id);
+  if (it == ltree_map_.end()) {
+    return nullptr;
+  } else {
+    // Found lock map.  Store in thread-local cache and return.
+    ltree_map_cache->insert({column_family_id, it->second});
+    return it->second;
+  }
+}
+
+struct LOCK_PRINT_CONTEXT {
+  RangeLockManagerHandle::RangeLockStatus* data;  // Save locks here
+  uint32_t cfh_id;  // Column Family whose tree we are traversing
+};
+
+// Report left endpoints of the acquired locks
+LockManager::PointLockStatus RangeTreeLockManager::GetPointLockStatus() {
+  PointLockStatus res;
+  LockManager::RangeLockStatus data = GetRangeLockStatus();
+  // report left endpoints
+  for (auto it = data.begin(); it != data.end(); ++it) {
+    auto& val = it->second;
+    res.insert({it->first, {val.start.slice, val.ids, val.exclusive}});
+  }
+  return res;
+}
+
+static void push_into_lock_status_data(void* param, const DBT* left,
+                                       const DBT* right, TXNID txnid_arg,
+                                       bool is_shared, TxnidVector* owners) {
+  struct LOCK_PRINT_CONTEXT* ctx = (LOCK_PRINT_CONTEXT*)param;
+  struct RangeLockInfo info;
+
+  info.exclusive = !is_shared;
+
+  deserialize_endpoint(left, &info.start);
+  deserialize_endpoint(right, &info.end);
+
+  if (txnid_arg != TXNID_SHARED) {
+    TXNID txnid = ((PessimisticTransaction*)txnid_arg)->GetID();
+    info.ids.push_back(txnid);
+  } else {
+    for (auto it : *owners) {
+      TXNID real_id = ((PessimisticTransaction*)it)->GetID();
+      info.ids.push_back(real_id);
+    }
+  }
+  ctx->data->insert({ctx->cfh_id, info});
+}
+
+LockManager::RangeLockStatus RangeTreeLockManager::GetRangeLockStatus() {
+  LockManager::RangeLockStatus data;
+  {
+    InstrumentedMutexLock l(&ltree_map_mutex_);
+    for (auto it : ltree_map_) {
+      LOCK_PRINT_CONTEXT ctx = {&data, it.first};
+      it.second->dump_locks((void*)&ctx, push_into_lock_status_data);
+    }
+  }
+  return data;
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+#endif  // OS_WIN
+#endif  // ROCKSDB_LITE

utilities/transactions/lock/range/range_tree/range_tree_lock_manager.h

@@ -0,0 +1,130 @@
+//  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
+#ifndef ROCKSDB_LITE
+#ifndef OS_WIN
+
+// For DeadlockInfoBuffer:
+#include "util/thread_local.h"
+#include "utilities/transactions/lock/point/point_lock_manager.h"
+#include "utilities/transactions/lock/range/range_lock_manager.h"
+
+// Lock Tree library:
+#include "utilities/transactions/lock/range/range_tree/lib/locktree/lock_request.h"
+#include "utilities/transactions/lock/range/range_tree/lib/locktree/locktree.h"
+#include "utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+using namespace toku;
+
+typedef DeadlockInfoBufferTempl<RangeDeadlockPath> RangeDeadlockInfoBuffer;
+
+// A Range Lock Manager that uses PerconaFT's locktree library
+class RangeTreeLockManager : public RangeLockManagerBase,
+                             public RangeLockManagerHandle {
+ public:
+  LockManager* getLockManager() override { return this; }
+
+  void AddColumnFamily(const ColumnFamilyHandle* cfh) override;
+  void RemoveColumnFamily(const ColumnFamilyHandle* cfh) override;
+
+  void Resize(uint32_t) override;
+  std::vector<DeadlockPath> GetDeadlockInfoBuffer() override;
+
+  std::vector<RangeDeadlockPath> GetRangeDeadlockInfoBuffer() override;
+  void SetRangeDeadlockInfoBufferSize(uint32_t target_size) override;
+
+  // Get a lock on a range
+  //  @note only exclusive locks are currently supported (requesting a
+  //  non-exclusive lock will get an exclusive one)
+  using LockManager::TryLock;
+  Status TryLock(PessimisticTransaction* txn, ColumnFamilyId column_family_id,
+                 const Endpoint& start_endp, const Endpoint& end_endp, Env* env,
+                 bool exclusive) override;
+
+  void UnLock(PessimisticTransaction* txn, const LockTracker& tracker,
+              Env* env) override;
+  void UnLock(PessimisticTransaction* txn, ColumnFamilyId column_family_id,
+              const std::string& key, Env* env) override;
+  void UnLock(PessimisticTransaction*, ColumnFamilyId, const Endpoint&,
+              const Endpoint&, Env*) override {
+    // TODO: range unlock does nothing...
+  }
+
+  explicit RangeTreeLockManager(
+      std::shared_ptr<TransactionDBMutexFactory> mutex_factory);
+
+  ~RangeTreeLockManager() override;
+
+  int SetMaxLockMemory(size_t max_lock_memory) override {
+    return ltm_.set_max_lock_memory(max_lock_memory);
+  }
+
+  size_t GetMaxLockMemory() override { return ltm_.get_max_lock_memory(); }
+
+  Counters GetStatus() override;
+
+  bool IsPointLockSupported() const override {
+    // One could have acquired a point lock (it is reduced to range lock)
+    return true;
+  }
+
+  PointLockStatus GetPointLockStatus() override;
+
+  // This is from LockManager
+  LockManager::RangeLockStatus GetRangeLockStatus() override;
+
+  // This has the same meaning as GetRangeLockStatus but is from
+  // RangeLockManagerHandle
+  RangeLockManagerHandle::RangeLockStatus GetRangeLockStatusData() override {
+    return GetRangeLockStatus();
+  }
+
+  bool IsRangeLockSupported() const override { return true; }
+
+  const LockTrackerFactory& GetLockTrackerFactory() const override {
+    return RangeTreeLockTrackerFactory::Get();
+  }
+
+  // Get the locktree which stores locks for the Column Family with given cf_id
+  std::shared_ptr<locktree> GetLockTreeForCF(ColumnFamilyId cf_id);
+
+ private:
+  toku::locktree_manager ltm_;
+
+  std::shared_ptr<TransactionDBMutexFactory> mutex_factory_;
+
+  // Map from cf_id to locktree*. Can only be accessed while holding the
+  // ltree_map_mutex_. Must use a custom deleter that calls ltm_.release_lt
+  using LockTreeMap =
+      std::unordered_map<ColumnFamilyId, std::shared_ptr<locktree>>;
+  LockTreeMap ltree_map_;
+
+  InstrumentedMutex ltree_map_mutex_;
+
+  // Per-thread cache of ltree_map_.
+  // (uses the same approach as TransactionLockMgr::lock_maps_cache_)
+  std::unique_ptr<ThreadLocalPtr> ltree_lookup_cache_;
+
+  RangeDeadlockInfoBuffer dlock_buffer_;
+
+  std::shared_ptr<locktree> MakeLockTreePtr(locktree* lt);
+  static int CompareDbtEndpoints(void* arg, const DBT* a_key, const DBT* b_key);
+
+  // Callbacks
+  static int on_create(locktree*, void*) { return 0; /* no error */ }
+  static void on_destroy(locktree*) {}
+  static void on_escalate(TXNID txnid, const locktree* lt,
+                          const range_buffer& buffer, void* extra);
+};
+
+void serialize_endpoint(const Endpoint& endp, std::string* buf);
+void wait_callback_for_locktree(void* cdata, lock_wait_infos* infos);
+
+}  // namespace ROCKSDB_NAMESPACE
+#endif  // OS_WIN
+#endif  // ROCKSDB_LITE

utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.cc

@@ -0,0 +1,156 @@
+//  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).
+
+#ifndef ROCKSDB_LITE
+#ifndef OS_WIN
+
+#include "utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.h"
+
+#include "utilities/transactions/lock/range/range_tree/range_tree_lock_manager.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+RangeLockList *RangeTreeLockTracker::getOrCreateList() {
+  if (range_list_) return range_list_.get();
+
+  // Doesn't exist, create
+  range_list_.reset(new RangeLockList());
+  return range_list_.get();
+}
+
+void RangeTreeLockTracker::Track(const PointLockRequest &lock_req) {
+  DBT key_dbt;
+  std::string key;
+  serialize_endpoint(Endpoint(lock_req.key, false), &key);
+  toku_fill_dbt(&key_dbt, key.data(), key.size());
+  RangeLockList *rl = getOrCreateList();
+  rl->Append(lock_req.column_family_id, &key_dbt, &key_dbt);
+}
+
+void RangeTreeLockTracker::Track(const RangeLockRequest &lock_req) {
+  DBT start_dbt, end_dbt;
+  std::string start_key, end_key;
+
+  serialize_endpoint(lock_req.start_endp, &start_key);
+  serialize_endpoint(lock_req.end_endp, &end_key);
+
+  toku_fill_dbt(&start_dbt, start_key.data(), start_key.size());
+  toku_fill_dbt(&end_dbt, end_key.data(), end_key.size());
+
+  RangeLockList *rl = getOrCreateList();
+  rl->Append(lock_req.column_family_id, &start_dbt, &end_dbt);
+}
+
+PointLockStatus RangeTreeLockTracker::GetPointLockStatus(
+    ColumnFamilyId /*cf_id*/, const std::string & /*key*/) const {
+  // This function is not expected to be called as RangeTreeLockTracker::
+  // IsPointLockSupported() returns false. Return the status which indicates
+  // the point is not locked.
+  PointLockStatus p;
+  p.locked = false;
+  p.exclusive = true;
+  p.seq = 0;
+  return p;
+}
+
+void RangeTreeLockTracker::Clear() { range_list_.reset(); }
+
+void RangeLockList::Append(ColumnFamilyId cf_id, const DBT *left_key,
+                           const DBT *right_key) {
+  MutexLock l(&mutex_);
+  // Only the transaction owner thread calls this function.
+  // The same thread does the lock release, so we can be certain nobody is
+  // releasing the locks concurrently.
+  assert(!releasing_locks_.load());
+  auto it = buffers_.find(cf_id);
+  if (it == buffers_.end()) {
+    // create a new one
+    it = buffers_.emplace(cf_id, std::make_shared<toku::range_buffer>()).first;
+    it->second->create();
+  }
+  it->second->append(left_key, right_key);
+}
+
+void RangeLockList::ReleaseLocks(RangeTreeLockManager *mgr,
+                                 PessimisticTransaction *txn,
+                                 bool all_trx_locks) {
+  {
+    MutexLock l(&mutex_);
+    // The lt->release_locks() call below will walk range_list->buffer_. We
+    // need to prevent lock escalation callback from replacing
+    // range_list->buffer_ while we are doing that.
+    //
+    // Additional complication here is internal mutex(es) in the locktree
+    // (let's call them latches):
+    // - Lock escalation first obtains latches on the lock tree
+    // - Then, it calls RangeTreeLockManager::on_escalate to replace
+    // transaction's range_list->buffer_. = Access to that buffer must be
+    // synchronized, so it will want to acquire the range_list->mutex_.
+    //
+    // While in this function we would want to do the reverse:
+    // - Acquire range_list->mutex_ to prevent access to the range_list.
+    // - Then, lt->release_locks() call will walk through the range_list
+    // - and acquire latches on parts of the lock tree to remove locks from
+    //   it.
+    //
+    // How do we avoid the deadlock? The idea is that here we set
+    // releasing_locks_=true, and release the mutex.
+    // All other users of the range_list must:
+    // - Acquire the mutex, then check that releasing_locks_=false.
+    //   (the code in this function doesnt do that as there's only one thread
+    //    that releases transaction's locks)
+    releasing_locks_.store(true);
+  }
+
+  for (auto it : buffers_) {
+    // Don't try to call release_locks() if the buffer is empty! if we are
+    //  not holding any locks, the lock tree might be in the STO-mode with
+    //  another transaction, and our attempt to release an empty set of locks
+    //  will cause an assertion failure.
+    if (it.second->get_num_ranges()) {
+      auto lt_ptr = mgr->GetLockTreeForCF(it.first);
+      toku::locktree *lt = lt_ptr.get();
+
+      lt->release_locks((TXNID)txn, it.second.get(), all_trx_locks);
+
+      it.second->destroy();
+      it.second->create();
+
+      toku::lock_request::retry_all_lock_requests(lt,
+                                                  wait_callback_for_locktree);
+    }
+  }
+
+  Clear();
+  releasing_locks_.store(false);
+}
+
+void RangeLockList::ReplaceLocks(const toku::locktree *lt,
+                                 const toku::range_buffer &buffer) {
+  MutexLock l(&mutex_);
+  if (releasing_locks_.load()) {
+    // Do nothing. The transaction is releasing its locks, so it will not care
+    // about having a correct list of ranges. (In TokuDB,
+    // toku_db_txn_escalate_callback() makes use of this property, too)
+    return;
+  }
+
+  ColumnFamilyId cf_id = (ColumnFamilyId)lt->get_dict_id().dictid;
+
+  auto it = buffers_.find(cf_id);
+  it->second->destroy();
+  it->second->create();
+
+  toku::range_buffer::iterator iter(&buffer);
+  toku::range_buffer::iterator::record rec;
+  while (iter.current(&rec)) {
+    it->second->append(rec.get_left_key(), rec.get_right_key());
+    iter.next();
+  }
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+#endif  // OS_WIN
+#endif  // ROCKSDB_LITE

utilities/transactions/lock/range/range_tree/range_tree_lock_tracker.h

@@ -0,0 +1,146 @@
+// 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 <memory>
+#include <string>
+#include <unordered_map>
+
+#include "util/mutexlock.h"
+#include "utilities/transactions/lock/lock_tracker.h"
+#include "utilities/transactions/pessimistic_transaction.h"
+
+// Range Locking:
+#include "lib/locktree/lock_request.h"
+#include "lib/locktree/locktree.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class RangeTreeLockManager;
+
+// Storage for locks that are currently held by a transaction.
+//
+// Locks are kept in toku::range_buffer because toku::locktree::release_locks()
+// accepts that as an argument.
+//
+// Note: the list of locks may differ slighly from the contents of the lock
+// tree, due to concurrency between lock acquisition, lock release, and lock
+// escalation. See MDEV-18227 and RangeTreeLockManager::UnLock for details.
+// This property is currently harmless.
+//
+// Append() and ReleaseLocks() are not thread-safe, as they are expected to be
+// called only by the owner transaction. ReplaceLocks() is safe to call from
+// other threads.
+class RangeLockList {
+ public:
+  ~RangeLockList() { Clear(); }
+
+  RangeLockList() : releasing_locks_(false) {}
+
+  void Append(ColumnFamilyId cf_id, const DBT* left_key, const DBT* right_key);
+  void ReleaseLocks(RangeTreeLockManager* mgr, PessimisticTransaction* txn,
+                    bool all_trx_locks);
+  void ReplaceLocks(const toku::locktree* lt, const toku::range_buffer& buffer);
+
+ private:
+  void Clear() {
+    for (auto it : buffers_) {
+      it.second->destroy();
+    }
+    buffers_.clear();
+  }
+
+  std::unordered_map<ColumnFamilyId, std::shared_ptr<toku::range_buffer>>
+      buffers_;
+  port::Mutex mutex_;
+  std::atomic<bool> releasing_locks_;
+};
+
+// A LockTracker-based object that is used together with RangeTreeLockManager.
+class RangeTreeLockTracker : public LockTracker {
+ public:
+  RangeTreeLockTracker() : range_list_(nullptr) {}
+
+  RangeTreeLockTracker(const RangeTreeLockTracker&) = delete;
+  RangeTreeLockTracker& operator=(const RangeTreeLockTracker&) = delete;
+
+  void Track(const PointLockRequest&) override;
+  void Track(const RangeLockRequest&) override;
+
+  bool IsPointLockSupported() const override {
+    // This indicates that we don't implement GetPointLockStatus()
+    return false;
+  }
+  bool IsRangeLockSupported() const override { return true; }
+
+  // a Not-supported dummy implementation.
+  UntrackStatus Untrack(const RangeLockRequest& /*lock_request*/) override {
+    return UntrackStatus::NOT_TRACKED;
+  }
+
+  UntrackStatus Untrack(const PointLockRequest& /*lock_request*/) override {
+    return UntrackStatus::NOT_TRACKED;
+  }
+
+  // "If this method is not supported, leave it as a no-op."
+  void Merge(const LockTracker&) override {}
+
+  // "If this method is not supported, leave it as a no-op."
+  void Subtract(const LockTracker&) override {}
+
+  void Clear() override;
+
+  // "If this method is not supported, returns nullptr."
+  virtual LockTracker* GetTrackedLocksSinceSavePoint(
+      const LockTracker&) const override {
+    return nullptr;
+  }
+
+  PointLockStatus GetPointLockStatus(ColumnFamilyId column_family_id,
+                                     const std::string& key) const override;
+
+  // The return value is only used for tests
+  uint64_t GetNumPointLocks() const override { return 0; }
+
+  ColumnFamilyIterator* GetColumnFamilyIterator() const override {
+    return nullptr;
+  }
+
+  KeyIterator* GetKeyIterator(
+      ColumnFamilyId /*column_family_id*/) const override {
+    return nullptr;
+  }
+
+  void ReleaseLocks(RangeTreeLockManager* mgr, PessimisticTransaction* txn,
+                    bool all_trx_locks) {
+    if (range_list_) range_list_->ReleaseLocks(mgr, txn, all_trx_locks);
+  }
+
+  void ReplaceLocks(const toku::locktree* lt,
+                    const toku::range_buffer& buffer) {
+    // range_list_ cannot be NULL here
+    range_list_->ReplaceLocks(lt, buffer);
+  }
+
+ private:
+  RangeLockList* getOrCreateList();
+  std::unique_ptr<RangeLockList> range_list_;
+};
+
+class RangeTreeLockTrackerFactory : public LockTrackerFactory {
+ public:
+  static const RangeTreeLockTrackerFactory& Get() {
+    static const RangeTreeLockTrackerFactory instance;
+    return instance;
+  }
+
+  LockTracker* Create() const override { return new RangeTreeLockTracker(); }
+
+ private:
+  RangeTreeLockTrackerFactory() {}
+};
+
+}  // namespace ROCKSDB_NAMESPACE

utilities/transactions/transaction_base.h

@@ -250,6 +250,8 @@ class TransactionBaseImpl : public Transaction {
 
   WriteBatch* GetCommitTimeWriteBatch() override;
 
+  LockTracker& GetTrackedLocks() { return *tracked_locks_; }
+
  protected:
   // Add a key to the list of tracked keys.
   //