Refactor sync_point to make implementation either customizable or replaceable

Summary: Closes https://github.com/facebook/rocksdb/pull/3637

Differential Revision: D7354373

Pulled By: ajkr

fbshipit-source-id: 6816c7bbc192ed0fb944942b11c7074bf24eddf1

CMakeLists.txt

@@ -569,6 +569,7 @@ set(SOURCES
         util/status_message.cc
         util/string_util.cc
         util/sync_point.cc
+        util/sync_point_impl.cc
         util/testutil.cc
         util/thread_local.cc
         util/threadpool_imp.cc

TARGETS

@@ -215,6 +215,7 @@ cpp_library(
         "util/status_message.cc",
         "util/string_util.cc",
         "util/sync_point.cc",
+        "util/sync_point_impl.cc",
         "util/thread_local.cc",
         "util/threadpool_imp.cc",
         "util/transaction_test_util.cc",

src.mk

@@ -148,6 +148,7 @@ LIB_SOURCES =                                                   \
   util/status_message.cc                                        \
   util/string_util.cc                                           \
   util/sync_point.cc                                            \
+  util/sync_point_impl.cc                                       \
   util/thread_local.cc                                          \
   util/threadpool_imp.cc                                        \
   util/transaction_test_util.cc                                 \

util/sync_point.cc

@@ -4,10 +4,7 @@
 //  (found in the LICENSE.Apache file in the root directory).
 
 #include "util/sync_point.h"
-#include <functional>
-#include <thread>
-#include "port/port.h"
-#include "util/random.h"
+#include "util/sync_point_impl.h"
 
 int rocksdb_kill_odds = 0;
 std::vector<std::string> rocksdb_kill_prefix_blacklist;
@@ -15,156 +12,57 @@ std::vector<std::string> rocksdb_kill_prefix_blacklist;
 #ifndef NDEBUG
 namespace rocksdb {
 
-void TestKillRandom(std::string kill_point, int odds,
-                    const std::string& srcfile, int srcline) {
-  for (auto& p : rocksdb_kill_prefix_blacklist) {
-    if (kill_point.substr(0, p.length()) == p) {
-      return;
-    }
-  }
-
-  assert(odds > 0);
-  if (odds % 7 == 0) {
-    // class Random uses multiplier 16807, which is 7^5. If odds are
-    // multiplier of 7, there might be limited values generated.
-    odds++;
-  }
-  auto* r = Random::GetTLSInstance();
-  bool crash = r->OneIn(odds);
-  if (crash) {
-    port::Crash(srcfile, srcline);
-  }
-}
-
 SyncPoint* SyncPoint::GetInstance() {
   static SyncPoint sync_point;
   return &sync_point;
 }
 
-void SyncPoint::LoadDependency(const std::vector<SyncPointPair>& dependencies) {
-  std::unique_lock<std::mutex> lock(mutex_);
-  successors_.clear();
-  predecessors_.clear();
-  cleared_points_.clear();
-  for (const auto& dependency : dependencies) {
-    successors_[dependency.predecessor].push_back(dependency.successor);
-    predecessors_[dependency.successor].push_back(dependency.predecessor);
-  }
-  cv_.notify_all();
+SyncPoint::SyncPoint() : 
+  impl_(new Data) {
 }
 
-void SyncPoint::LoadDependencyAndMarkers(
-    const std::vector<SyncPointPair>& dependencies,
-    const std::vector<SyncPointPair>& markers) {
-  std::unique_lock<std::mutex> lock(mutex_);
-  successors_.clear();
-  predecessors_.clear();
-  cleared_points_.clear();
-  markers_.clear();
-  marked_thread_id_.clear();
-  for (const auto& dependency : dependencies) {
-    successors_[dependency.predecessor].push_back(dependency.successor);
-    predecessors_[dependency.successor].push_back(dependency.predecessor);
-  }
-  for (const auto& marker : markers) {
-    successors_[marker.predecessor].push_back(marker.successor);
-    predecessors_[marker.successor].push_back(marker.predecessor);
-    markers_[marker.predecessor].push_back(marker.successor);
-  }
-  cv_.notify_all();
+SyncPoint:: ~SyncPoint() {
+  delete impl_;
 }
 
-bool SyncPoint::PredecessorsAllCleared(const std::string& point) {
-  for (const auto& pred : predecessors_[point]) {
-    if (cleared_points_.count(pred) == 0) {
-      return false;
-    }
-  }
-  return true;
+void SyncPoint::LoadDependency(const std::vector<SyncPointPair>& dependencies) {
+  impl_->LoadDependency(dependencies);
 }
 
-void SyncPoint::SetCallBack(const std::string point,
-                            std::function<void(void*)> callback) {
-  std::unique_lock<std::mutex> lock(mutex_);
-  callbacks_[point] = callback;
+void SyncPoint::LoadDependencyAndMarkers(
+  const std::vector<SyncPointPair>& dependencies,
+  const std::vector<SyncPointPair>& markers) {
+  impl_->LoadDependencyAndMarkers(dependencies, markers);
 }
 
-void SyncPoint::ClearCallBack(const std::string point) {
-  std::unique_lock<std::mutex> lock(mutex_);
-  while (num_callbacks_running_ > 0) {
-    cv_.wait(lock);
-  }
-  callbacks_.erase(point);
+void SyncPoint::SetCallBack(const std::string& point,
+  const std::function<void(void*)>& callback) {
+  impl_->SetCallBack(point, callback);
+}
+
+void SyncPoint::ClearCallBack(const std::string& point) {
+  impl_->ClearCallBack(point);
 }
 
 void SyncPoint::ClearAllCallBacks() {
-  std::unique_lock<std::mutex> lock(mutex_);
-  while (num_callbacks_running_ > 0) {
-    cv_.wait(lock);
-  }
-  callbacks_.clear();
+  impl_->ClearAllCallBacks();
 }
 
 void SyncPoint::EnableProcessing() {
-  std::unique_lock<std::mutex> lock(mutex_);
-  enabled_ = true;
+  impl_->EnableProcessing();
 }
 
 void SyncPoint::DisableProcessing() {
-  std::unique_lock<std::mutex> lock(mutex_);
-  enabled_ = false;
+  impl_->DisableProcessing();
 }
 
 void SyncPoint::ClearTrace() {
-  std::unique_lock<std::mutex> lock(mutex_);
-  cleared_points_.clear();
-}
-
-bool SyncPoint::DisabledByMarker(const std::string& point,
-                                 std::thread::id thread_id) {
-  auto marked_point_iter = marked_thread_id_.find(point);
-  return marked_point_iter != marked_thread_id_.end() &&
-         thread_id != marked_point_iter->second;
+  impl_->ClearTrace();
 }
 
 void SyncPoint::Process(const std::string& point, void* cb_arg) {
-  std::unique_lock<std::mutex> lock(mutex_);
-  if (!enabled_) {
-    return;
-  }
-
-  auto thread_id = std::this_thread::get_id();
-
-  auto marker_iter = markers_.find(point);
-  if (marker_iter != markers_.end()) {
-    for (auto marked_point : marker_iter->second) {
-      marked_thread_id_.insert(std::make_pair(marked_point, thread_id));
-    }
-  }
-
-  if (DisabledByMarker(point, thread_id)) {
-    return;
-  }
-
-  while (!PredecessorsAllCleared(point)) {
-    cv_.wait(lock);
-    if (DisabledByMarker(point, thread_id)) {
-      return;
-    }
-  }
-
-  auto callback_pair = callbacks_.find(point);
-  if (callback_pair != callbacks_.end()) {
-    num_callbacks_running_++;
-    mutex_.unlock();
-    callback_pair->second(cb_arg);
-    mutex_.lock();
-    num_callbacks_running_--;
-    cv_.notify_all();
-  }
-
-  cleared_points_.insert(point);
-  cv_.notify_all();
+  impl_->Process(point, cb_arg);
 }
+
 }  // namespace rocksdb
 #endif  // NDEBUG

util/sync_point.h

@@ -5,13 +5,10 @@
 #pragma once
 
 #include <assert.h>
-#include <condition_variable>
 #include <functional>
 #include <mutex>
 #include <string>
 #include <thread>
-#include <unordered_map>
-#include <unordered_set>
 #include <vector>
 
 // This is only set from db_stress.cc and for testing only.
@@ -65,6 +62,10 @@ class SyncPoint {
  public:
   static SyncPoint* GetInstance();
 
+  SyncPoint(const SyncPoint&) = delete;
+  SyncPoint& operator=(const SyncPoint&) = delete;
+  ~SyncPoint();
+
   struct SyncPointPair {
     std::string predecessor;
     std::string successor;
@@ -81,15 +82,14 @@ class SyncPoint {
   void LoadDependencyAndMarkers(const std::vector<SyncPointPair>& dependencies,
                                 const std::vector<SyncPointPair>& markers);
 
-  // Set up a call back function in sync point.
   // The argument to the callback is passed through from
   // TEST_SYNC_POINT_CALLBACK(); nullptr if TEST_SYNC_POINT or
   // TEST_IDX_SYNC_POINT was used.
-  void SetCallBack(const std::string point,
-                   std::function<void(void*)> callback);
+  void SetCallBack(const std::string& point,
+                   const std::function<void(void*)>& callback);
 
   // Clear callback function by point
-  void ClearCallBack(const std::string point);
+  void ClearCallBack(const std::string& point);
 
   // Clear all call back functions.
   void ClearAllCallBacks();
@@ -111,29 +111,20 @@ class SyncPoint {
   // TODO: it might be useful to provide a function that blocks until all
   // sync points are cleared.
 
+  // We want this to be public so we can
+  // subclass the implementation
+  struct Data;
+
  private:
-  bool PredecessorsAllCleared(const std::string& point);
-  bool DisabledByMarker(const std::string& point, std::thread::id thread_id);
-
-  // successor/predecessor map loaded from LoadDependency
-  std::unordered_map<std::string, std::vector<std::string>> successors_;
-  std::unordered_map<std::string, std::vector<std::string>> predecessors_;
-  std::unordered_map<std::string, std::function<void(void*)> > callbacks_;
-  std::unordered_map<std::string, std::vector<std::string> > markers_;
-  std::unordered_map<std::string, std::thread::id> marked_thread_id_;
-
-  std::mutex mutex_;
-  std::condition_variable cv_;
-  // sync points that have been passed through
-  std::unordered_set<std::string> cleared_points_;
-  bool enabled_ = false;
-  int num_callbacks_running_ = 0;
+   // Singleton
+  SyncPoint();
+  Data*  impl_;
 };
 
 }  // namespace rocksdb
 
 // Use TEST_SYNC_POINT to specify sync points inside code base.
-// Sync points can have happens-after dependency on other sync points,
+// Sync points can have happens-after depedency on other sync points,
 // configured at runtime via SyncPoint::LoadDependency. This could be
 // utilized to re-produce race conditions between threads.
 // See TransactionLogIteratorRace in db_test.cc for an example use case.

util/sync_point_impl.cc

@@ -0,0 +1,129 @@
+//  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 "util/sync_point_impl.h"
+
+#ifndef NDEBUG
+namespace rocksdb {
+
+void TestKillRandom(std::string kill_point, int odds,
+                    const std::string& srcfile, int srcline) {
+  for (auto& p : rocksdb_kill_prefix_blacklist) {
+    if (kill_point.substr(0, p.length()) == p) {
+      return;
+    }
+  }
+
+  assert(odds > 0);
+  if (odds % 7 == 0) {
+    // class Random uses multiplier 16807, which is 7^5. If odds are
+    // multiplier of 7, there might be limited values generated.
+    odds++;
+  }
+  auto* r = Random::GetTLSInstance();
+  bool crash = r->OneIn(odds);
+  if (crash) {
+    port::Crash(srcfile, srcline);
+  }
+}
+
+
+void SyncPoint::Data::LoadDependency(const std::vector<SyncPointPair>& dependencies) {
+  std::lock_guard<std::mutex> lock(mutex_);
+  successors_.clear();
+  predecessors_.clear();
+  cleared_points_.clear();
+  for (const auto& dependency : dependencies) {
+    successors_[dependency.predecessor].push_back(dependency.successor);
+    predecessors_[dependency.successor].push_back(dependency.predecessor);
+  }
+  cv_.notify_all();
+}
+
+void SyncPoint::Data::LoadDependencyAndMarkers(
+  const std::vector<SyncPointPair>& dependencies,
+  const std::vector<SyncPointPair>& markers) {
+  std::lock_guard<std::mutex> lock(mutex_);
+  successors_.clear();
+  predecessors_.clear();
+  cleared_points_.clear();
+  markers_.clear();
+  marked_thread_id_.clear();
+  for (const auto& dependency : dependencies) {
+    successors_[dependency.predecessor].push_back(dependency.successor);
+    predecessors_[dependency.successor].push_back(dependency.predecessor);
+  }
+  for (const auto& marker : markers) {
+    successors_[marker.predecessor].push_back(marker.successor);
+    predecessors_[marker.successor].push_back(marker.predecessor);
+    markers_[marker.predecessor].push_back(marker.successor);
+  }
+  cv_.notify_all();
+}
+
+bool SyncPoint::Data::PredecessorsAllCleared(const std::string& point) {
+  for (const auto& pred : predecessors_[point]) {
+    if (cleared_points_.count(pred) == 0) {
+      return false;
+    }
+  }
+  return true;
+}
+
+void SyncPoint::Data::ClearCallBack(const std::string& point) {
+  std::unique_lock<std::mutex> lock(mutex_);
+  while (num_callbacks_running_ > 0) {
+    cv_.wait(lock);
+  }
+  callbacks_.erase(point);
+}
+
+void SyncPoint::Data::ClearAllCallBacks() {
+  std::unique_lock<std::mutex> lock(mutex_);
+  while (num_callbacks_running_ > 0) {
+    cv_.wait(lock);
+  }
+  callbacks_.clear();
+}
+
+void SyncPoint::Data::Process(const std::string& point, void* cb_arg) {
+  std::unique_lock<std::mutex> lock(mutex_);
+  if (!enabled_) {
+    return;
+  }
+
+  auto thread_id = std::this_thread::get_id();
+
+  auto marker_iter = markers_.find(point);
+  if (marker_iter != markers_.end()) {
+    for (auto& marked_point : marker_iter->second) {
+      marked_thread_id_.emplace(marked_point, thread_id);
+    }
+  }
+
+  if (DisabledByMarker(point, thread_id)) {
+    return;
+  }
+
+  while (!PredecessorsAllCleared(point)) {
+    cv_.wait(lock);
+    if (DisabledByMarker(point, thread_id)) {
+      return;
+    }
+  }
+
+  auto callback_pair = callbacks_.find(point);
+  if (callback_pair != callbacks_.end()) {
+    num_callbacks_running_++;
+    mutex_.unlock();
+    callback_pair->second(cb_arg);
+    mutex_.lock();
+    num_callbacks_running_--;
+  }
+  cleared_points_.insert(point);
+  cv_.notify_all();
+}
+} // rocksdb
+#endif

util/sync_point_impl.h

@@ -0,0 +1,74 @@
+//  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 "util/sync_point.h"
+
+#include <assert.h>
+#include <condition_variable>
+#include <functional>
+#include <mutex>
+#include <string>
+#include <thread>
+#include <unordered_map>
+#include <unordered_set>
+
+#include "port/port.h"
+#include "util/random.h"
+
+#pragma once
+
+#ifndef NDEBUG
+namespace rocksdb {
+struct SyncPoint::Data {
+  // Enable proper deletion by subclasses
+  virtual ~Data() {}
+  // successor/predecessor map loaded from LoadDependency
+  std::unordered_map<std::string, std::vector<std::string>> successors_;
+  std::unordered_map<std::string, std::vector<std::string>> predecessors_;
+  std::unordered_map<std::string, std::function<void(void*)> > callbacks_;
+  std::unordered_map<std::string, std::vector<std::string> > markers_;
+  std::unordered_map<std::string, std::thread::id> marked_thread_id_;
+
+  std::mutex              mutex_;
+  std::condition_variable cv_;
+  // sync points that have been passed through
+  std::unordered_set<std::string> cleared_points_;
+  bool enabled_ = false;
+  int num_callbacks_running_ = 0;
+
+  void LoadDependency(const std::vector<SyncPointPair>& dependencies);
+  void LoadDependencyAndMarkers(const std::vector<SyncPointPair>& dependencies,
+    const std::vector<SyncPointPair>& markers);
+  bool PredecessorsAllCleared(const std::string& point);
+  void SetCallBack(const std::string& point,
+    const std::function<void(void*)>& callback) {
+  std::lock_guard<std::mutex> lock(mutex_);
+  callbacks_[point] = callback;
+}
+
+  void ClearCallBack(const std::string& point);
+  void ClearAllCallBacks();
+  void EnableProcessing() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    enabled_ = true;
+  }
+  void DisableProcessing() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    enabled_ = false;
+  }
+  void ClearTrace() {
+    std::lock_guard<std::mutex> lock(mutex_);
+    cleared_points_.clear();
+  }
+  bool DisabledByMarker(const std::string& point,
+                        std::thread::id thread_id) {
+    auto marked_point_iter = marked_thread_id_.find(point);
+    return marked_point_iter != marked_thread_id_.end() &&
+           thread_id != marked_point_iter->second;
+  }
+  void Process(const std::string& point, void* cb_arg);
+};
+}
+#endif // NDEBUG