C++11 标准引入了<condition_variable>头文件,它提供了一种机制,允许线程在某些条件不满足时挂起,直到其他线程通知它们条件已经满足。 condition_variable是用于线程间同步的一种高级工具,它比使用低级同步原语(如互斥锁和条件变量)更加安全和方便。 condition_variable是一个类模板,用于在多线程环境中实现线程间的同步。
if predictable scheduling behaviour is required, then that mutex is locked by the thread calling pthread_cond_signal() or pthread_cond_broadcast(). std::condition_variable - cppreference
std::condition_variable_any类 与std::condition_variable类似,只不过std::condition_variable_any的wait函数可以接受任何lockadle参数。而std::condition_variable只能接受std::unique_lock类型的参数,除此意外和std::condition_variable几乎完全一样。 condition_variable代码实例 #include<iostream>#include<string>#inclu...
// conditionVariables.cpp #include <condition_variable> #include <iostream> #include <thread> std::mutex mutex_; std::condition_variable condVar; bool dataReady{false}; void waitingForWork(){ std::cout << "Waiting " << std::endl; std::unique_lock<std::mutex> lck(mutex_); condVar.wai...
先贴一个condition_variable的讲解:https://en.cppreference.com/w/cpp/thread/condition_variable,很详细也很全面,但是是英文的,劝退了一部分英语不好的人(也包括我),但是借助翻译还是大概可以看下来的,而且里面的两个代码也很有代表性,使用的生产者消费者模式,推给大家。
当前线程会一直被阻塞,直到另外一个线程在相同的 std::condition_variable 对象上调用了 notification 函数来唤醒当前线程。 std::condition_variable对象通常使用std::unique_lock<std::mutex>来等待,如果需要使用另外的lockable类型,可以使用 std::condition_variable_any 类,本文后面会讲到 std::condition_variable_...
cppreference.com 创建账户 std::condition_variable 在标头<condition_variable>定义 classcondition_variable; (C++11 起) std::condition_variable是与std::mutex一起使用的同步原语,它能用于阻塞一个线程,或同时阻塞多个线程,直至另一线程修改共享变量(条件)并通知std::condition_variable。
// conditionVariable.cpp#include <iostream>#include <condition_variable>#include <mutex>#include <thread>std::mutex mutex_; std::condition_variable condVar;voiddoTheWork(){ std::cout <<"Processing shared data."<< std::endl; }voidwaitingForWork(){ ...
stdcondition_variable astdmutex breadyidstd::unique_lock<std::mutex>lock(b);a.wait(lock,[]{returnready;});std::cout<<id<<" is proceeding.\n";}intmain(){std::threadx1(x,1);std::threadx2(x,2);std::this_thread::sleep_for(std::chrono::seconds(1));{std::lock_guard<std::mute...
1. What is the primary purpose of a condition variable in C++? A. To manage threads B. To signal between threads C. To create mutexes D. To handle exceptions Show Answer 2. Which header file is required to use condition variables in C++? A. <iostream> B. <thread> C. <...