platform_hardware_libhardwa.../power.cpp
Kalesh Singh d8da2af1e5 RAII style wakelocks: Add tryGet() factory method.
Wakelock acquisition can fail if suspend service is not available.
Make this clear by returning an optional value that client must
check before entering wakelock critical sections.

Bug: b/179229598
Test: Boot test on Pixel 4 device
Change-Id: Ied00fa919c20d8a30f1c40ee34a91a2a7e240689
2021-02-23 10:06:19 -05:00

138 lines
4.2 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 <hardware_legacy/power.h>
#include <wakelock/wakelock.h>
#include <android-base/logging.h>
#include <android/system/suspend/1.0/ISystemSuspend.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) {
LOG(ERROR) << "ISystemSuspend::getService() failed.";
return -1;
}
std::lock_guard<std::mutex> l{gLock};
if (!gWakeLockMap[id]) {
auto ret = suspendService->acquireWakeLock(WakeLockType::PARTIAL, id);
// It's possible that during device shutdown SystemSuspend service has already exited. In
// these situations HIDL calls to it will result in a DEAD_OBJECT transaction error. We
// check for DEAD_OBJECT so that libpower clients can shutdown cleanly.
if (ret.isDeadObject()) {
return -1;
} else {
gWakeLockMap[id] = ret;
}
}
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;
}
namespace android {
namespace wakelock {
class WakeLock::WakeLockImpl {
public:
WakeLockImpl(const std::string& name);
~WakeLockImpl();
bool acquireOk();
private:
sp<IWakeLock> mWakeLock;
};
std::optional<WakeLock> WakeLock::tryGet(const std::string& name) {
std::unique_ptr<WakeLockImpl> wlImpl = std::make_unique<WakeLockImpl>(name);
if (wlImpl->acquireOk()) {
return { std::move(wlImpl) };
} else {
LOG(ERROR) << "Failed to acquire wakelock: " << name;
return {};
}
}
WakeLock::WakeLock(std::unique_ptr<WakeLockImpl> wlImpl) : mImpl(std::move(wlImpl)) {}
WakeLock::~WakeLock() = default;
WakeLock::WakeLockImpl::WakeLockImpl(const std::string& name) : mWakeLock(nullptr) {
static sp<ISystemSuspend> suspendService = ISystemSuspend::getService();
auto ret = suspendService->acquireWakeLock(WakeLockType::PARTIAL, name);
// It's possible that during device SystemSuspend service is not avaiable. In these
// situations HIDL calls to it will result in a DEAD_OBJECT transaction error.
if (ret.isDeadObject()) {
LOG(ERROR) << "ISuspendService::acquireWakeLock() call failed: " << ret.description();
} else {
mWakeLock = ret;
}
}
WakeLock::WakeLockImpl::~WakeLockImpl() {
if (!acquireOk()) {
return;
}
auto ret = mWakeLock->release();
if (!ret.isOk()) {
LOG(ERROR) << "IWakeLock::release() call failed: " << ret.description();
}
}
bool WakeLock::WakeLockImpl::acquireOk() {
return mWakeLock != nullptr;
}
} // namespace wakelock
} // namespace android