std::condition_variable voidwait(std::unique_lock<std::mutex>&lock); (1)(C++11 起) template<classPredicate> voidwait(std::unique_lock<std::mutex>&lock, Predicate pred); (2)(C++11 起) wait导致当前线程阻塞直至条件变量被通知,或虚假唤醒发生。可以提供pred以检测虚假唤醒。
wait(lock); } returnpred(); 在wait返回时,并且调用线程会锁定lock。如果无法满足此后条件[1],那么就会调用std::terminate。 ↑重新锁定互斥体的过程中抛出异常就会发生这种情况。 参数 lock-必须已经由调用线程锁定的锁 stoken-用于注册中断的停止令牌
具体来说,可以使用std::condition_variable和std::mutex来实现线程的暂停和恢复。 首先,需要定义一个std::condition_variable对象和一个std::mutex对象,用于线程之间的同步和通信。然后,在父线程中,可以通过调用std::condition_variable的wait()函数来暂停子线程的执行。wait()函数会使当前线程阻塞,直到其他线程调用not...
如果你用到了条件变量 std::condition_variable::wait 则必须使用 std::unique_lock 作为参数。 例如: #include<iostream> #include<thread> intv=1; voidcritical_section(intchange_v) { staticstd::mutexmtx; std::unique_lock<std::mutex>lock(mtx); // 执行竞争操作 v=change_v; std::cout<<v<<s...
#pragma once #include<thread> #include<condition_variable> #include<atomic> namespace AsyncSystem { class Event { public: Event() { _set = false; } bool wait() { while (!_set) { std::unique_lock<std::mutex> lock(_mutex); if (!_set) { _cond.wait(lock); // 这里应该是把锁让...
A condition variable is always used in conjunction with a mutex. The mutex provides mutual exclusion for accessing the shared variable, while the condition variable is used to signal changes in the variable’s state. 条件变量总是结合mutex使用,条件变量就共享变量的状态改变发出通知,mutex就是用来保护...
A condition variable is always used in conjunction with a mutex. The mutex provides mutual exclusion for accessing the shared variable, while the condition variable is used to signal changes in the variable’s state. 条件变量总是结合mutex使用,条件变量就共享变量的状态改变发出通知,mutex就是用来保护...
_condition.wait(lck);LOG(INFO) <<"thread "<< std::this_thread::get_id(); } voidgo() { std::unique_lock<std::mutex>lck(_mutex); _ready =true; _condition.notify_all(); } };// A simple threadpool implementation.class ThreadPool { ...
类是同步原语 //https://zh.cppreference.com/w/cpp/thread/condition_variable 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 condition_variable 。 当std::condition_variable 对象的某个 wait 函数被调用的时候,它使用 std::unique_lock(通过 std::mutex) 来锁住当前线程。当...
recognize this situation and avoid this "hurry up and wait" scenario by transferring the waiting thread from the condition variable's queue directly to the queue of the mutex within the notify call, without waking it up. Question 1: Is this a good advice? Question 2: Would it make sense ...