rocksdb/util/sync_point.h
sdong 6e9fbeb27c Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env
Summary: We want to keep Env a think layer for better portability. Less platform dependent codes should be moved out of Env. In this patch, I create a wrapper of file readers and writers, and put rate limiting, write buffering, as well as most perf context instrumentation and random kill out of Env. It will make it easier to maintain multiple Env in the future.

Test Plan: Run all existing unit tests.

Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D42321
2015-07-17 16:58:18 -07:00

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4.1 KiB
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// Copyright (c) 2014, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
#pragma once
#include <assert.h>
#include <condition_variable>
#include <mutex>
#include <string>
#include <unordered_set>
#include <unordered_map>
#include <vector>
// This is only set from db_stress.cc and for testing only.
// If non-zero, kill at various points in source code with probability 1/this
extern int rocksdb_kill_odds;
#ifdef NDEBUG
// empty in release build
#define TEST_KILL_RANDOM(rocksdb_kill_odds)
#else
namespace rocksdb {
// Kill the process with probablity 1/odds for testing.
extern void TestKillRandom(int odds, const std::string& srcfile, int srcline);
// To avoid crashing always at some frequently executed codepaths (during
// kill random test), use this factor to reduce odds
#define REDUCE_ODDS 2
#define REDUCE_ODDS2 4
#define TEST_KILL_RANDOM(rocksdb_kill_odds) \
{ \
if (rocksdb_kill_odds > 0) { \
TestKillRandom(rocksdb_kill_odds, __FILE__, __LINE__); \
} \
}
} // namespace rocksdb
#endif
#ifdef NDEBUG
#define TEST_SYNC_POINT(x)
#define TEST_SYNC_POINT_CALLBACK(x, y)
#else
namespace rocksdb {
// This class provides facility to reproduce race conditions deterministically
// in unit tests.
// Developer could specify sync points in the codebase via TEST_SYNC_POINT.
// Each sync point represents a position in the execution stream of a thread.
// In the unit test, 'Happens After' relationship among sync points could be
// setup via SyncPoint::LoadDependency, to reproduce a desired interleave of
// threads execution.
// Refer to (DBTest,TransactionLogIteratorRace), for an exmaple use case.
class SyncPoint {
public:
static SyncPoint* GetInstance();
struct Dependency {
std::string predecessor;
std::string successor;
};
// call once at the beginning of a test to setup the dependency between
// sync points
void LoadDependency(const std::vector<Dependency>& dependencies);
// Set up a call back function in sync point.
void SetCallBack(const std::string point,
std::function<void(void*)> callback);
// Clear all call back functions.
void ClearAllCallBacks();
// enable sync point processing (disabled on startup)
void EnableProcessing();
// disable sync point processing
void DisableProcessing();
// remove the execution trace of all sync points
void ClearTrace();
// triggered by TEST_SYNC_POINT, blocking execution until all predecessors
// are executed.
// And/or call registered callback functionn, with argument `cb_arg`
void Process(const std::string& point, void* cb_arg = nullptr);
// TODO: it might be useful to provide a function that blocks until all
// sync points are cleared.
private:
bool PredecessorsAllCleared(const std::string& point);
// 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::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;
};
} // namespace rocksdb
// Use TEST_SYNC_POINT to specify sync points inside code base.
// 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.
// TEST_SYNC_POINT is no op in release build.
#define TEST_SYNC_POINT(x) rocksdb::SyncPoint::GetInstance()->Process(x)
#define TEST_SYNC_POINT_CALLBACK(x, y) \
rocksdb::SyncPoint::GetInstance()->Process(x, y)
#endif // NDEBUG