gecko-dev/mozglue/misc/PlatformConditionVariable.h

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2.1 KiB
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_ConditionVariable_h
#define mozilla_ConditionVariable_h
#include <stdint.h>
#include <utility>
#include "mozilla/Attributes.h"
#include "mozilla/PlatformMutex.h"
#include "mozilla/TimeStamp.h"
#if !defined(XP_WIN) && !defined(__wasi__)
# include <pthread.h>
#endif
namespace mozilla {
enum class CVStatus { NoTimeout, Timeout };
namespace detail {
class ConditionVariableImpl {
public:
struct PlatformData;
MFBT_API ConditionVariableImpl();
MFBT_API ~ConditionVariableImpl();
// Wake one thread that is waiting on this condition.
MFBT_API void notify_one();
// Wake all threads that are waiting on this condition.
MFBT_API void notify_all();
// Atomically release |lock| and sleep the current thread of execution on
// this condition variable.
// |lock| will be re-acquired before this function returns.
// The thread may be woken from sleep from another thread via notify_one()
// or notify_all(), but may also wake spuriously. The caller should recheck
// its predicate after this function returns, typically in a while loop.
MFBT_API void wait(MutexImpl& lock);
MFBT_API CVStatus wait_for(MutexImpl& lock,
const mozilla::TimeDuration& rel_time);
private:
ConditionVariableImpl(const ConditionVariableImpl&) = delete;
ConditionVariableImpl& operator=(const ConditionVariableImpl&) = delete;
PlatformData* platformData();
#if !defined(XP_WIN) && !defined(__wasi__)
void* platformData_[sizeof(pthread_cond_t) / sizeof(void*)];
static_assert(sizeof(pthread_cond_t) / sizeof(void*) != 0 &&
sizeof(pthread_cond_t) % sizeof(void*) == 0,
"pthread_cond_t must have pointer alignment");
#else
void* platformData_[4];
#endif
};
} // namespace detail
} // namespace mozilla
#endif // mozilla_ConditionVariable_h