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C17异步任务需要future和promise配合使用#xff0c;不是很喜欢那种语法。实现一个操作简洁的异步任务。
满足功能
异步任务超时控制get接口同步任务计时lambda回调任务重启
使用
#include async_callback.h
#include unistd.h
#includ…为什么写这个
C17异步任务需要future和promise配合使用不是很喜欢那种语法。实现一个操作简洁的异步任务。
满足功能
异步任务超时控制get接口同步任务计时lambda回调任务重启
使用
#include async_callback.h
#include unistd.h
#include iostream
using namespace std;int main() {int a 0, b 0, c 0;AsyncTask* task1 new AsyncTask([a](){sleep(2);for (int i 0; i 10000; i) {a;}});AsyncTask* task2 new AsyncTask([b](){sleep(2);for (int i 0; i 10000; i) {b;}});if (!task1-get(1)) {cout task1超时 endl;}if (task2-get()) {cout task2没超时 endl;}task1-restart();task2-restart();task1-get();task2-get();cout a endl;cout b endl;cout task1执行时间: task1-executionTime() endl;cout task2执行时间: task2-executionTime() endl;return 0;
}打印结果
task1超时
task2没超时
20000
20000
task1执行时间:2.00009
task2执行时间:2.00009代码
// Simple asynchronous tasks with timeout
// Author: Y. F. Zhang
// Date: 2023-09-21#ifndef ASYNC_CALLBACK_H
#define ASYNC_CALLBACK_H#include mutex
#include condition_variable
#include thread
#include atomic
#include functional
#include exception
#include iostream
#include sys/time.h
#include time.h
class Timer {
public:Timer() {offsetTime_ 0;timerState_ TIMERSTOP;}void timerStart() {timerState_ TIMERRUN;timeStamp_ getWallTime();}double elapsedTime() {if (timerState_ TIMERPAUSE) {return offsetTime_;}curTime_ getWallTime() - timeStamp_ offsetTime_;if (timerState_ TIMERSTOP) return 0;return curTime_;}void pauseTimer() {offsetTime_ getWallTime() - timeStamp_; timerState_ TIMERPAUSE;}void stopTimer() {offsetTime_ 0;curTime_ 0;timerState_ TIMERSTOP;}private:double getWallTime() {struct timeval time ;if (gettimeofday(time,NULL)){return 0;}return (double)time.tv_sec (double)time.tv_usec * .000001;}double timeStamp_;double curTime_;double offsetTime_;enum{TIMERSTOP,TIMERRUN,TIMERPAUSE} timerState_;
};namespace AsyncTaskException {class GetButTaskStopErr: public std::exception {const char* what() const throw () {return invoke get method but task is stop!;}
};class GetExecutionTimeButTaskStopErr: public std::exception {const char* what() const throw () {return invoke executionTime method but task is stop!;}
};}using func std::functionvoid();
class AsyncTask {
private:enum {TASKRUNNING,TASKSTOP,TASKFINISHED} taskState_;func callback_;std::mutex mtx_;std::condition_variable cond_;std::atomic_bool completedFlag_;std::thread* taskThread_;Timer timer_;void initTask() {timer_.stopTimer();taskState_ TASKSTOP;completedFlag_.store(false);if (taskThread_ ! nullptr) {delete taskThread_;taskThread_ nullptr;}}void runTask() {auto wrapperCallback [this]() {try {timer_.timerStart();callback_();timer_.pauseTimer();completedFlag_.store(true);} catch (std::exception e) {fprintf(stderr, %s, e.what());}taskState_ TASKFINISHED;cond_.notify_one();};taskState_ TASKRUNNING;taskThread_ new std::thread(wrapperCallback);taskThread_-detach();}
public:AsyncTask(func callback) {this-callback_ callback;restart();}void restart() {initTask();runTask();}double executionTime() {if (taskState_ TASKSTOP) {throw AsyncTaskException::GetExecutionTimeButTaskStopErr();}return timer_.elapsedTime();}~AsyncTask() {if (taskThread_ ! nullptr) {delete taskThread_;}}bool get(size_t timeoutSec 0) {if (taskState_ TASKSTOP) {throw AsyncTaskException::GetButTaskStopErr();}std::unique_lockstd::mutex lk(mtx_);if (timeoutSec 0) {cond_.wait(lk, [this](){return completedFlag_.load();});} else {return cond_.wait_for(lk, std::chrono::seconds(timeoutSec), [this](){return completedFlag_.load();});}return true;}};#endif
