Promise: 专业的 future 提供商 // promise example #include <iostream> // std::cout #include <functional> // std::ref #include <thread> // std::thread #include <future> // std::promise, std::future void print_int (std::future<int>& fut) { int x = fut.get(); std::cout << ...
#include<iostream>#include<thread>#include<future>voidmodifyMessage(std::promise<std::string>&&proms,std::string msg){std::string metaMsg=msg+" has been modified";proms.set_value(metaMsg);}intmain(){std::string msg_str="My Message";//创建promise对象std::promise<std::string>proms;//创建...
std::future<int> f = p.get_future(); // can be copy std::shared_future<int> sf = f.share(); std::future<int> fu1 = std::async(std::launch::async, factorial, sf); std::future<int> fu2 = std::async(std::launch::async, factorial, sf); std::future<int> fu3 = std::...
unique_future用来存储packaged_task异步计算得到的future值,它只能持有结果的唯一的一个应用。成员函数wait()可以阻塞等待packaged_task的执行,直至获得future值。成员函数is_ready()、has_value()和has_exception()分别用来测试unique_future是否可用,是否有值和是否发生了异常,如果一切正常那么可以使用get()获得future值...
future是模板类,线程方法返回值的类型,就是模板的类型。 代码: #include<future>#include<iostream>#include<unistd.h>intreturn_from_thread(intval){ std::cout << val << std::endl;//sleep(1);returnval; }voiddo_something(){ std::cout <<"在等滴滴来车"<< std::endl; ...
Promise / Future library in c ###Installation git clone https://github.com/emef/cfutures ./autogen.sh ./configure make sudo make install Future executor pool example usage (from selftests) typedefstruct{inta,b; }test_args_t;void*test_future_fn(void*args) {test_args_t*test_args=(test...
问题:请解释C++11中的std::future和std::promise的关系和作用。 参考答案:std::future代表一个异步操作的结果,它可以在将来某个时候获得。std::promise是一个与std::future相关联的对象,用于在某个线程中设置std::future的值。当std::promise的值被设置时,与之关联的std::future可以获得这个值。
//打开文件 FILE * fopen ( const char * filename, const char * mode ); //If the file is successfully opened, the function returns a pointer to a FILE object that can be used to identify the stream on future operations. //Otherwise, a null pointer is returned. //关闭文件 int fclose...
// Run in context CompletableFuture<String> future = VertxCompletableFuture.supplyAsync(vertx, () -> return "foo";); // Run in Vert.x worker thread CompletableFuture<String> future = VertxCompletableFuture.supplyBlockingAsync(vertx, () -> return "foo"); CompletableFuture<Void> future = ...
#include <future> #include <random> #include <chrono> #include <exception> using namespace std; void doSomething(int num, char c); int main() { try { //开启一个线程(不分离) std::thread t1(doSomething, 5, '.'); std::cout << "- started fg thread " << t1.get_id() << std...