platform_hardware_libhardwa.../power.cpp
Tri Vo ca0b45a15e Handle concurrent exit and wake lock acquisition.
We use "-Wexit-time-destructors" and "-fno-c++-static-destructors" flags
to make sure that no static variables are destroyed at exit time.

We do this to avoid the race condition between process exit and use of
static vars when calling acquire/release_wake_lock().

Bug: 117575503
Test: libpower_test
Change-Id: I16acfeb2412685e376d8bd1069c86f60f56d215a
2018-11-28 16:04:12 -08:00

71 lines
2.2 KiB
C++

/*
* Copyright (C) 2018 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.
*/
#define LOG_TAG "power"
#define ATRACE_TAG ATRACE_TAG_POWER
#include <android-base/logging.h>
#include <android/system/suspend/1.0/ISystemSuspend.h>
#include <hardware_legacy/power.h>
#include <utils/Trace.h>
#include <mutex>
#include <string>
#include <thread>
#include <unordered_map>
using android::sp;
using android::system::suspend::V1_0::ISystemSuspend;
using android::system::suspend::V1_0::IWakeLock;
using android::system::suspend::V1_0::WakeLockType;
static std::mutex gLock;
static std::unordered_map<std::string, sp<IWakeLock>> gWakeLockMap;
static const sp<ISystemSuspend>& getSystemSuspendServiceOnce() {
static sp<ISystemSuspend> suspendService = ISystemSuspend::getService();
return suspendService;
}
int acquire_wake_lock(int, const char* id) {
ATRACE_CALL();
const auto& suspendService = getSystemSuspendServiceOnce();
if (!suspendService) {
return -1;
}
std::lock_guard<std::mutex> l{gLock};
if (!gWakeLockMap[id]) {
gWakeLockMap[id] = suspendService->acquireWakeLock(WakeLockType::PARTIAL, id);
}
return 0;
}
int release_wake_lock(const char* id) {
ATRACE_CALL();
std::lock_guard<std::mutex> l{gLock};
if (gWakeLockMap[id]) {
// Ignore errors on release() call since hwbinder driver will clean up the underlying object
// once we clear the corresponding strong pointer.
auto ret = gWakeLockMap[id]->release();
if (!ret.isOk()) {
LOG(ERROR) << "IWakeLock::release() call failed: " << ret.description();
}
gWakeLockMap[id].clear();
return 0;
}
return -1;
}