rocksdb/monitoring/instrumented_mutex.h
mrambacher 12f1137355 Add a SystemClock class to capture the time functions of an Env (#7858)
Summary:
Introduces and uses a SystemClock class to RocksDB.  This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.

Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead.  There are likely more places that can be changed, but this is a start to show what can/should be done.  Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.

There are several Env classes that implement these functions.  Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR.  It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).

Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858

Reviewed By: pdillinger

Differential Revision: D26006406

Pulled By: mrambacher

fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
2021-01-25 22:09:11 -08:00

104 lines
2.6 KiB
C++

// 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 "monitoring/statistics.h"
#include "port/port.h"
#include "rocksdb/statistics.h"
#include "rocksdb/system_clock.h"
#include "rocksdb/thread_status.h"
#include "util/stop_watch.h"
namespace ROCKSDB_NAMESPACE {
class InstrumentedCondVar;
// A wrapper class for port::Mutex that provides additional layer
// for collecting stats and instrumentation.
class InstrumentedMutex {
public:
explicit InstrumentedMutex(bool adaptive = false)
: mutex_(adaptive), stats_(nullptr), clock_(nullptr), stats_code_(0) {}
explicit InstrumentedMutex(const std::shared_ptr<SystemClock>& clock,
bool adaptive = false)
: mutex_(adaptive), stats_(nullptr), clock_(clock), stats_code_(0) {}
InstrumentedMutex(Statistics* stats,
const std::shared_ptr<SystemClock>& clock, int stats_code,
bool adaptive = false)
: mutex_(adaptive),
stats_(stats),
clock_(clock),
stats_code_(stats_code) {}
void Lock();
void Unlock() {
mutex_.Unlock();
}
void AssertHeld() {
mutex_.AssertHeld();
}
private:
void LockInternal();
friend class InstrumentedCondVar;
port::Mutex mutex_;
Statistics* stats_;
std::shared_ptr<SystemClock> clock_;
int stats_code_;
};
// A wrapper class for port::Mutex that provides additional layer
// for collecting stats and instrumentation.
class InstrumentedMutexLock {
public:
explicit InstrumentedMutexLock(InstrumentedMutex* mutex) : mutex_(mutex) {
mutex_->Lock();
}
~InstrumentedMutexLock() {
mutex_->Unlock();
}
private:
InstrumentedMutex* const mutex_;
InstrumentedMutexLock(const InstrumentedMutexLock&) = delete;
void operator=(const InstrumentedMutexLock&) = delete;
};
class InstrumentedCondVar {
public:
explicit InstrumentedCondVar(InstrumentedMutex* instrumented_mutex)
: cond_(&(instrumented_mutex->mutex_)),
stats_(instrumented_mutex->stats_),
clock_(instrumented_mutex->clock_),
stats_code_(instrumented_mutex->stats_code_) {}
void Wait();
bool TimedWait(uint64_t abs_time_us);
void Signal() {
cond_.Signal();
}
void SignalAll() {
cond_.SignalAll();
}
private:
void WaitInternal();
bool TimedWaitInternal(uint64_t abs_time_us);
port::CondVar cond_;
Statistics* stats_;
const std::shared_ptr<SystemClock> clock_;
int stats_code_;
};
} // namespace ROCKSDB_NAMESPACE