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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "AutoConditionLock.h"
namespace android {
WaitableMutexWrapper::WaitableMutexWrapper(Mutex* mutex) : mMutex{mutex}, mState{false} {}
WaitableMutexWrapper::~WaitableMutexWrapper() {}
// Locks manager-owned mutex
AutoConditionLock::AutoConditionLock(const std::shared_ptr<WaitableMutexWrapper>& manager) :
mManager{manager}, mAutoLock{manager->mMutex} {}
// Unlocks manager-owned mutex
AutoConditionLock::~AutoConditionLock() {
// Unset the condition and wake everyone up before releasing lock
mManager->mState = false;
mManager->mCondition.broadcast();
}
std::unique_ptr<AutoConditionLock> AutoConditionLock::waitAndAcquire(
const std::shared_ptr<WaitableMutexWrapper>& manager, nsecs_t waitTime) {
if (manager == nullptr || manager->mMutex == nullptr) {
// Bad input, return null
return std::unique_ptr<AutoConditionLock>{nullptr};
}
// Acquire scoped lock
std::unique_ptr<AutoConditionLock> scopedLock(new AutoConditionLock(manager));
// Figure out what time in the future we should hit the timeout
nsecs_t failTime = systemTime(SYSTEM_TIME_MONOTONIC) + waitTime;
// Wait until we timeout, or success
while(manager->mState) {
status_t ret = manager->mCondition.waitRelative(*(manager->mMutex), waitTime);
if (ret != NO_ERROR) {
// Timed out or whatever, return null
return std::unique_ptr<AutoConditionLock>{nullptr};
}
waitTime = failTime - systemTime(SYSTEM_TIME_MONOTONIC);
}
// Set the condition and return
manager->mState = true;
return scopedLock;
}
std::unique_ptr<AutoConditionLock> AutoConditionLock::waitAndAcquire(
const std::shared_ptr<WaitableMutexWrapper>& manager) {
if (manager == nullptr || manager->mMutex == nullptr) {
// Bad input, return null
return std::unique_ptr<AutoConditionLock>{nullptr};
}
// Acquire scoped lock
std::unique_ptr<AutoConditionLock> scopedLock(new AutoConditionLock(manager));
// Wait until we timeout, or success
while(manager->mState) {
status_t ret = manager->mCondition.wait(*(manager->mMutex));
if (ret != NO_ERROR) {
// Timed out or whatever, return null
return std::unique_ptr<AutoConditionLock>{nullptr};
}
}
// Set the condition and return
manager->mState = true;
return scopedLock;
}
}; // namespace android
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