android13/packages/modules/adb/client/openscreen/platform/task_runner.cpp

121 lines
3.6 KiB
C++

/*
* Copyright (C) 2020 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 "client/openscreen/platform/task_runner.h"
#include <chrono>
#include <vector>
#include <android-base/logging.h>
#include <android-base/threads.h>
#include <platform/api/time.h>
#include "fdevent/fdevent.h"
using android::base::ScopedLockAssertion;
using namespace openscreen;
namespace mdns {
AdbOspTaskRunner::AdbOspTaskRunner() {
check_main_thread();
thread_id_ = android::base::GetThreadId();
task_handler_ = std::thread([this]() { TaskExecutorWorker(); });
}
AdbOspTaskRunner::~AdbOspTaskRunner() {
if (task_handler_.joinable()) {
terminate_loop_ = true;
cv_.notify_one();
task_handler_.join();
}
}
void AdbOspTaskRunner::PostPackagedTask(Task task) {
PostPackagedTaskWithDelay(std::move(task), openscreen::Clock::duration::zero());
}
void AdbOspTaskRunner::PostPackagedTaskWithDelay(Task task, Clock::duration delay) {
auto now = std::chrono::steady_clock::now();
{
std::lock_guard<std::mutex> lock(mutex_);
tasks_.emplace(now + delay, std::move(task));
}
cv_.notify_one();
}
bool AdbOspTaskRunner::IsRunningOnTaskRunner() {
return (thread_id_ == android::base::GetThreadId());
}
void AdbOspTaskRunner::TaskExecutorWorker() {
for (;;) {
{
// Wait until there's a task available.
std::unique_lock<std::mutex> lock(mutex_);
ScopedLockAssertion assume_locked(mutex_);
while (!terminate_loop_ && tasks_.empty()) {
cv_.wait(lock);
}
if (terminate_loop_) {
return;
}
// Wait until the task with the closest time point is ready to run.
auto timepoint = tasks_.begin()->first;
while (timepoint > std::chrono::steady_clock::now()) {
cv_.wait_until(lock, timepoint);
// It's possible that another task with an earlier time was added
// while waiting for |timepoint|.
timepoint = tasks_.begin()->first;
if (terminate_loop_) {
return;
}
}
}
// Execute all tasks whose time points have passed.
std::vector<Task> running_tasks;
{
std::lock_guard<std::mutex> lock(mutex_);
while (!tasks_.empty()) {
auto task_with_delay = tasks_.begin();
if (task_with_delay->first > std::chrono::steady_clock::now()) {
break;
} else {
running_tasks.emplace_back(std::move(task_with_delay->second));
tasks_.erase(task_with_delay);
}
}
}
CHECK(!running_tasks.empty());
std::packaged_task<int()> waitable_task([&] {
for (Task& task : running_tasks) {
task();
}
return 0;
});
fdevent_run_on_main_thread([&]() { waitable_task(); });
waitable_task.get_future().wait();
}
}
} // namespace mdns