线程问题

Question

我正在读Bruce Eckel的书"Thinking in C++", vol. 2，而在第11章练习13时我遇到了一个问题。

练习13：创建两个Runnable子类，一个带有run（），启动并调用wait（）。另一个类的run（）应该捕获第一个Runnable对象的引用。它的run（）应该在经过一些秒后调用第一个线程的signal（），这样第一个线程就可以打印一条消息。

Runnable类来自ZThreads库。

这是我的代码：

#include <iostream>
#include "zthread/Runnable.h"
#include "zthread/Condition.h"
#include "zthread/Mutex.h"
#include "zthread/Guard.h"
#include "zthread/CountedPtr.h"
#include "zthread/Thread.h"

class Class1: public ZThread::Runnable {
    ZThread::Mutex lock;
    ZThread::Condition condition;
public:
    Class1(): condition(lock) {}

    void run() {
        ZThread::Guard<ZThread::Mutex> g(lock);
        std::cout << "Class1::run()\n";
        condition.wait();
        std::cout << "Message\n";
    }

    void continue1() {
        ZThread::Guard<ZThread::Mutex> g(lock);
        std::cout << "Class1::continue1()\n";
        condition.signal();
    }
};

class Class2: public ZThread::Runnable {
    ZThread::CountedPtr<Class1>& c;
public:
    Class2(ZThread::CountedPtr<Class1>& c1): c(c1) {}

    void run() {
        std::cout << "Class2::run()\n";
        ZThread::Thread::sleep(2000);
        std::cout << "Calling continue1()\n";
        c->continue1();
        std::cout << "Exiting Class2::run()\n";
    }
};

int main() {
    ZThread::CountedPtr<Class1> c(new Class1);
    std::cout << "Starting thread 1\n";
    ZThread::Thread t1(c);
    std::cout << "Starting thread 2\n";
    ZThread::Thread t2(new Class2(c));
    std::cout << "exit\n";
}

它挂起并且不打印“消息”。我做错了什么？

Answer 1

您的程序以函数main结束，两个线程都被中断。将sleep添加到main函数的末尾。