gecko-dev/mozglue/misc/ConditionVariable_windows.cpp

97 строки
3.1 KiB
C++

/* -*- 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/. */
#include "mozilla/Assertions.h"
#include <float.h>
#include <intrin.h>
#include <stdlib.h>
#include <windows.h>
#include "mozilla/PlatformConditionVariable.h"
#include "mozilla/PlatformMutex.h"
#include "MutexPlatformData_windows.h"
// Some versions of the Windows SDK have a bug where some interlocked functions
// are not redefined as compiler intrinsics. Fix that for the interlocked
// functions that are used in this file.
#if defined(_MSC_VER) && !defined(InterlockedExchangeAdd)
#define InterlockedExchangeAdd(addend, value) \
_InterlockedExchangeAdd((volatile long*)(addend), (long)(value))
#endif
#if defined(_MSC_VER) && !defined(InterlockedIncrement)
#define InterlockedIncrement(addend) \
_InterlockedIncrement((volatile long*)(addend))
#endif
// Wrapper for native condition variable APIs.
struct mozilla::detail::ConditionVariableImpl::PlatformData
{
CONDITION_VARIABLE cv_;
};
mozilla::detail::ConditionVariableImpl::ConditionVariableImpl()
{
InitializeConditionVariable(&platformData()->cv_);
}
void
mozilla::detail::ConditionVariableImpl::notify_one()
{
WakeConditionVariable(&platformData()->cv_);
}
void
mozilla::detail::ConditionVariableImpl::notify_all()
{
WakeAllConditionVariable(&platformData()->cv_);
}
void
mozilla::detail::ConditionVariableImpl::wait(MutexImpl& lock)
{
CRITICAL_SECTION* cs = &lock.platformData()->criticalSection;
bool r = SleepConditionVariableCS(&platformData()->cv_, cs, INFINITE);
MOZ_RELEASE_ASSERT(r);
}
mozilla::detail::CVStatus
mozilla::detail::ConditionVariableImpl::wait_for(MutexImpl& lock,
const mozilla::TimeDuration& rel_time)
{
CRITICAL_SECTION* cs = &lock.platformData()->criticalSection;
// Note that DWORD is unsigned, so we have to be careful to clamp at 0.
// If rel_time is Forever, then ToMilliseconds is +inf, which evaluates as
// greater than UINT32_MAX, resulting in the correct INFINITE wait.
double msecd = rel_time.ToMilliseconds();
DWORD msec = msecd < 0.0
? 0
: msecd > UINT32_MAX
? INFINITE
: static_cast<DWORD>(msecd);
BOOL r = SleepConditionVariableCS(&platformData()->cv_, cs, msec);
if (r)
return CVStatus::NoTimeout;
MOZ_RELEASE_ASSERT(GetLastError() == ERROR_TIMEOUT);
return CVStatus::Timeout;
}
mozilla::detail::ConditionVariableImpl::~ConditionVariableImpl()
{
// Native condition variables don't require cleanup.
}
inline mozilla::detail::ConditionVariableImpl::PlatformData*
mozilla::detail::ConditionVariableImpl::platformData()
{
static_assert(sizeof platformData_ >= sizeof(PlatformData),
"platformData_ is too small");
return reinterpret_cast<PlatformData*>(platformData_);
}