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// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/synchronization/condition_variable.h"
#include <windows.h>
#include <optional>
#include "base/numerics/safe_conversions.h"
#include "base/synchronization/lock.h"
#include "base/threading/scoped_blocking_call.h"
#include "base/threading/thread_restrictions.h"
#include "base/time/time.h"
namespace base {
ConditionVariable::ConditionVariable(Lock* user_lock)
: srwlock_(user_lock->lock_.native_handle())
#if DCHECK_IS_ON()
,
user_lock_(user_lock)
#endif
{
DCHECK(user_lock);
InitializeConditionVariable(reinterpret_cast<PCONDITION_VARIABLE>(&cv_));
}
ConditionVariable::~ConditionVariable() = default;
void ConditionVariable::Wait() {
TimedWait(TimeDelta::Max());
}
void ConditionVariable::TimedWait(const TimeDelta& max_time) {
std::optional<internal::ScopedBlockingCallWithBaseSyncPrimitives>
scoped_blocking_call;
if (waiting_is_blocking_) {
scoped_blocking_call.emplace(FROM_HERE, BlockingType::MAY_BLOCK);
}
// Limit timeout to INFINITE.
DWORD timeout = saturated_cast<DWORD>(max_time.InMilliseconds());
#if DCHECK_IS_ON()
user_lock_->CheckHeldAndUnmark();
#endif
if (!SleepConditionVariableSRW(reinterpret_cast<PCONDITION_VARIABLE>(&cv_),
reinterpret_cast<PSRWLOCK>(srwlock_.get()),
timeout, 0)) {
// On failure, we only expect the CV to timeout. Any other error value means
// that we've unexpectedly woken up.
// Note that WAIT_TIMEOUT != ERROR_TIMEOUT. WAIT_TIMEOUT is used with the
// WaitFor* family of functions as a direct return value. ERROR_TIMEOUT is
// used with GetLastError().
DCHECK_EQ(static_cast<DWORD>(ERROR_TIMEOUT), GetLastError());
}
#if DCHECK_IS_ON()
user_lock_->CheckUnheldAndMark();
#endif
}
void ConditionVariable::Broadcast() {
WakeAllConditionVariable(reinterpret_cast<PCONDITION_VARIABLE>(&cv_));
}
void ConditionVariable::Signal() {
WakeConditionVariable(reinterpret_cast<PCONDITION_VARIABLE>(&cv_));
}
} // namespace base
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