Question

我的问题是：在一个封装了boost :: condition_variable的线程的析构函数中，我需要做些什么（比如调用notify_all？）。以下代码在调用Test析构函数时生成此断言：

cond_var： /usr/include/boost/thread/pthread/condition_variable_fwd.hpp:38： boost :: condition_variable :: ~condition_variable（）：断言 `！pthread_cond_destroy（＆amp; cond）'失败了。中止

#include <boost/thread/mutex.hpp>
#include <boost/thread/condition_variable.hpp>
#include <boost/thread.hpp>

class Test {
public:

    ~Test() { /* ??? */ }

    int getI() {
        boost::mutex::scoped_lock lock(mtx);
        cond_var.wait(lock);
        return i;
    }

    void putI() {
        i=10;
        cond_var.notify_one();
    }

    int i;

    boost::mutex mtx;
    boost::condition_variable cond_var;
} t;

void runPut () {
    for(;;) {
        t.getI();
    }
}

void runGet () {
    for(;;) {
        t.putI();
        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
    }
}

int main() {
    boost::thread t1(&runPut);
    boost::thread t2(&runGet);

    boost::this_thread::sleep(boost::posix_time::seconds(5));
    return 0;
}

（gdb）bt

0  0x00007ffff70c4d05 in raise () from /lib/x86_64-linux-gnu/libc.so.6
1  0x00007ffff70c8ab6 in abort () from /lib/x86_64-linux-gnu/libc.so.6
2  0x00007ffff70bd7c5 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6
3  0x0000000000406a35 in boost::condition_variable::~condition_variable (this=0x6104d0,
__in_chrg=<value optimized out>) at /usr/include/boost/thread/pthread/condition
_variable_fwd.hpp:38
4  0x0000000000406f42 in Test::~Test (this=0x6104a0, __in_chrg=<value optimized out>) at cond_var.cpp:19
5  0x00007ffff70ca961 in exit () from /lib/x86_64-linux-gnu/libc.so.6
6  0x00007ffff70aff06 in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
7  0x0000000000405899 in _start ()

Answer 1

在退出之前，您需要加入您创建的两个主题。添加一个名为say，'stop'的全局布尔变量，初始化为false，并让t1和t2在每次迭代时检查它是否为false：

bool stop = false;

void runPut () {
    while( !stop ) {
        t.getI();
    }
}

void runGet () {
    while( !stop ) {
        t.putI();
        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
    }
}

然后在主要睡眠之后将其设置为true，并在t1和t2上调用join。

boost::this_thread::sleep(boost::posix_time::seconds(5));
stop = true;
t1.join();
t2.join();

否则条件变量在使用时会被破坏。

提升condition_variable destroy断言

1 个答案: