提升condition_variable銷燬聲明

Question

我的問題是：是否有某種特定的需要做的事情（如調用notify_all？）在封裝boost :: condition_variable的線程的析構函數中。下面的代碼生成此斷言當測試調用析構函數：

cond_var： /usr/include/boost/thread/pthread/condition_variable_fwd.hpp:38： 的boost :: condition_variable ::〜condition_variable（） ：聲明 '！pthread_cond_destroy（& cond）'失敗。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

您需要在退出之前，加入你所創建的兩個線程。添加一個全局的布爾變量叫說，「停止」，初始化爲假，並有T1和T2的支票，這是錯誤的每次迭代：

bool stop = false; 

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

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

然後在它的主要設置爲true你的睡眠，並加入到通話後t1和t2。

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

否則條件變量在使用中會被破壞。