sync_point_impl.cc

//  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) {
  if (!enabled_) {
    return;
  }

  std::unique_lock<std::mutex> lock(mutex_);
  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