blob: 46b8bc07b432a9f02d7ae6a36470018dec0f40bd [file] [log] [blame]
/*
* Copyright (C) 2017 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.
*/
#ifndef HWUI_WORKQUEUE_H
#define HWUI_WORKQUEUE_H
#include "utils/Macros.h"
#include <log/log.h>
#include <utils/Timers.h>
#include <condition_variable>
#include <functional>
#include <future>
#include <mutex>
#include <vector>
namespace android::uirenderer {
struct MonotonicClock {
static nsecs_t now() { return systemTime(SYSTEM_TIME_MONOTONIC); }
};
class WorkQueue {
PREVENT_COPY_AND_ASSIGN(WorkQueue);
public:
using clock = MonotonicClock;
private:
struct WorkItem {
WorkItem() = delete;
WorkItem(const WorkItem& other) = delete;
WorkItem& operator=(const WorkItem& other) = delete;
WorkItem(WorkItem&& other) = default;
WorkItem& operator=(WorkItem&& other) = default;
WorkItem(nsecs_t runAt, std::function<void()>&& work)
: runAt(runAt), work(std::move(work)) {}
nsecs_t runAt;
std::function<void()> work;
};
public:
WorkQueue(std::function<void()>&& wakeFunc, std::mutex& lock)
: mWakeFunc(move(wakeFunc)), mLock(lock) {}
void process() {
auto now = clock::now();
std::vector<WorkItem> toProcess;
{
std::unique_lock _lock{mLock};
if (mWorkQueue.empty()) return;
toProcess = std::move(mWorkQueue);
auto moveBack = find_if(std::begin(toProcess), std::end(toProcess),
[&now](WorkItem& item) { return item.runAt > now; });
if (moveBack != std::end(toProcess)) {
mWorkQueue.reserve(std::distance(moveBack, std::end(toProcess)) + 5);
std::move(moveBack, std::end(toProcess), std::back_inserter(mWorkQueue));
toProcess.erase(moveBack, std::end(toProcess));
}
}
for (auto& item : toProcess) {
item.work();
}
}
template <class F>
void postAt(nsecs_t time, F&& func) {
enqueue(WorkItem{time, std::function<void()>(std::forward<F>(func))});
}
template <class F>
void postDelayed(nsecs_t delay, F&& func) {
enqueue(WorkItem{clock::now() + delay, std::function<void()>(std::forward<F>(func))});
}
template <class F>
void post(F&& func) {
postAt(0, std::forward<F>(func));
}
template <class F>
auto async(F&& func) -> std::future<decltype(func())> {
typedef std::packaged_task<decltype(func())()> task_t;
auto task = std::make_shared<task_t>(std::forward<F>(func));
post([task]() { std::invoke(*task); });
return task->get_future();
}
template <class F>
auto runSync(F&& func) -> decltype(func()) {
std::packaged_task<decltype(func())()> task{std::forward<F>(func)};
post([&task]() { std::invoke(task); });
return task.get_future().get();
};
nsecs_t nextWakeup(std::unique_lock<std::mutex>& lock) {
if (mWorkQueue.empty()) {
return std::numeric_limits<nsecs_t>::max();
} else {
return std::begin(mWorkQueue)->runAt;
}
}
private:
void enqueue(WorkItem&& item) {
bool needsWakeup;
{
std::unique_lock _lock{mLock};
auto insertAt = std::find_if(
std::begin(mWorkQueue), std::end(mWorkQueue),
[time = item.runAt](WorkItem & item) { return item.runAt > time; });
needsWakeup = std::begin(mWorkQueue) == insertAt;
mWorkQueue.emplace(insertAt, std::move(item));
}
if (needsWakeup) {
mWakeFunc();
}
}
std::function<void()> mWakeFunc;
std::mutex& mLock;
std::vector<WorkItem> mWorkQueue;
};
} // namespace android::uirenderer
#endif // HWUI_WORKQUEUE_H