std::packaged_task::make_ready_at_thread_exit
void make_ready_at_thread_exit( ArgTypes... args ); | ? | (since C++11) |
|---|
调用已转发的存储任务args作为争论。任务或其引发的任何异常的返回值存储在*this...
的所有对象和当前线程退出之后，共享状态才会就绪。线程局部存储时间被销毁。
参数
args | - | the parameters to pass on invocation of the stored task |
|---|
返回值
%280%29
例外
std::future_error在下列错误条件下：
- 存储的任务已经被调用。错误类别设置为
promise_already_satisfied...
*this没有共享状态。错误类别设置为no_state...
例
二次
#include <future>
#include <iostream>
#include <chrono>
#include <thread>
#include <functional>
#include <utility>
void worker(std::future<void>& output)
{
std::packaged_task<void(bool&)> my_task{ [](bool& done) { done=true; } };
auto result = my_task.get_future();
bool done = false;
my_task.make_ready_at_thread_exit(done); // execute task right away
std::cout << "worker: done = " << std::boolalpha << done << std::endl;
auto status = result.wait_for(std::chrono::seconds(0));
if (status == std::future_status::timeout)
std::cout << "worker: result is not ready yet" << std::endl;
output = std::move(result);
}
int main()
{
std::future<void> result;
std::thread{worker, std::ref(result)}.join();
auto status = result.wait_for(std::chrono::seconds(0));
if (status == std::future_status::ready)
std::cout << "main: result is ready" << std::endl;
}二次
产出：
二次
worker: done = true
worker: result is not ready yet
main: result is ready二次
另见
operator() | executes the function (public member function) |
|---|
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