3ae9c5309b
Summary: Fixes https://github.com/facebook/rocksdb/issues/9779. The padding at the end of a struct is added implicitly according to the sizeof spec: "When applied to a class, the result is the number of bytes in an object of that class including any padding required for placing objects of that type in an array" (https://eel.is/c++draft/expr.sizeof#2.sentence-2). We should drop the explicit padding since it assumed support for zero-length arrays, which is non-standard. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9809 Test Plan: rely on CI Reviewed By: riversand963 Differential Revision: D35413496 Pulled By: ajkr fbshipit-source-id: 25d52ca45e648ad0d5657149f26f6adecbed1cb4
124 lines
3.2 KiB
C++
124 lines
3.2 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(SystemClock* clock, bool adaptive = false)
|
|
: mutex_(adaptive), stats_(nullptr), clock_(clock), stats_code_(0) {}
|
|
|
|
InstrumentedMutex(Statistics* stats, 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_;
|
|
SystemClock* clock_;
|
|
int stats_code_;
|
|
};
|
|
|
|
class ALIGN_AS(CACHE_LINE_SIZE) CacheAlignedInstrumentedMutex
|
|
: public InstrumentedMutex {
|
|
using InstrumentedMutex::InstrumentedMutex;
|
|
};
|
|
static_assert(alignof(CacheAlignedInstrumentedMutex) != CACHE_LINE_SIZE ||
|
|
sizeof(CacheAlignedInstrumentedMutex) % CACHE_LINE_SIZE == 0);
|
|
|
|
// RAII wrapper for InstrumentedMutex
|
|
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;
|
|
};
|
|
|
|
// RAII wrapper for temporary releasing InstrumentedMutex inside
|
|
// InstrumentedMutexLock
|
|
class InstrumentedMutexUnlock {
|
|
public:
|
|
explicit InstrumentedMutexUnlock(InstrumentedMutex* mutex) : mutex_(mutex) {
|
|
mutex_->Unlock();
|
|
}
|
|
|
|
~InstrumentedMutexUnlock() { mutex_->Lock(); }
|
|
|
|
private:
|
|
InstrumentedMutex* const mutex_;
|
|
InstrumentedMutexUnlock(const InstrumentedMutexUnlock&) = delete;
|
|
void operator=(const InstrumentedMutexUnlock&) = 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_;
|
|
SystemClock* clock_;
|
|
int stats_code_;
|
|
};
|
|
|
|
} // namespace ROCKSDB_NAMESPACE
|