c – 信号处理期间的堆损坏

我有一个多线程 Windows服务器,我正在研究,发现在我通过control-c关闭程序时出现一定的标准后,它崩溃了.如果我的服务器从客户端接收数据包然后我使用control-c,它会崩溃.如果我启动我的服务器,让它等待任何时间段的数据包,然后使用control-c,它会正常退出.

然而,有什么奇怪的是,即使程序确实抛出异常(除非那是正常的),我的所有线程都报告他们正以状态0退出.

First-chance exception at 0x75A16DA7 (kernel32.dll) in server.exe: 0x40010005: Control-C.
HEAP[server.exe]: HEAP: Free Heap block 96a818 modified at 96a908 after it was freed
server.exe has triggered a breakpoint.
The thread 0xc34 has exited with code 0 (0x0).
The thread 0x1c64 has exited with code 0 (0x0).
The thread 0xdbc has exited with code 0 (0x0).
The thread 0x117c has exited with code 0 (0x0).
The thread 0x1444 has exited with code 0 (0x0).
The thread 0x1d60 has exited with code 0 (0x0).
The thread 0x798 has exited with code 0 (0x0).
The thread 0x700 has exited with code 0 (0x0).
The thread 0x1bbc has exited with code 0 (0x0).
The thread 0x1b74 has exited with code 0 (0x0).
The program '[7528] server.exe' has exited with code 0 (0x0).

代码的一部分似乎是导致此问题的原因：

void handleSignal(int sig) {
    std::unique_lock<std::mutex> lock(signalMutex); // <-- comment out and it doesn't crash
    signaled = true;
    _receivedSignal = sig;
    signalHandlerCondition.notify_one(); // <-- comment out and it doesn't crash
}

互斥和条件变量都是全局变量：

std::mutex signalMutex;
std::condition_variable signalHandlerCondition;

我有一个专用的信号处理线程,试图在该事件通知时正常关闭服务器.

void run() {
    while (gContinueRunning && _continueRunning) {
        std::unique_lock<std::mutex> lock(signalMutex);
        signalHandlerCondition.wait(lock);
        if (signaled) {
            gContinueRunning = false;
            signaled = false;
            Server::stop();
        }
    }
}

当然,当我注释掉有问题的线路时,程序根本不响应信号.我可以有一个wait_for,这样我就不必通知信号处理循环它有一个新信号,但我不认为这是最好的方法.

我确实从MSDN上读到了有关信号的内容：

When a CTRL+C interrupt occurs,Win32 operating systems generate a new
thread to specifically handle that interrupt.

Because signal-handler routines are usually called asynchronously when an interrupt
occurs,your signal-handler function may get control when a run-time operation is
incomplete and in an unknown state.

老实说,我不确定这是否适用于这种情况.如果确实如此,这是否意味着在调用信号处理程序时,我的互斥锁可能存在也可能不存在？

那么,接近信号的最佳方法是什么？我遇到什么问题？

编辑：只是为了清除一些事情：

void start() {
    _receivedSignal = 0;
    _continueRunning = true;
    // start thread
    std::thread signalHandlerThread(run);
    _signalHandlerThread = std::move(signalHandlerThread);

    // register signals
    signal(SIGABRT,SignalHandler::handleSignal);
    signal(SIGTERM,SignalHandler::handleSignal);
    signal(SIGINT,SignalHandler::handleSignal);
}

即使在删除互斥锁后,程序似乎也会进一步发展 – 尽管只有在主要完成之后.

msvcr110d.dll!operator delete(void * pUserData) Line 52 C++
server.exe!std::_Ref_count<User>::_Destroy() Line 161   C++
server.exe!std::_Ref_count_base::_Decref() Line 120 C++
server.exe!std::_Ptr_base<User>::_Decref() Line 347 C++
server.exe!std::shared_ptr<User>::~shared_ptr<User>() Line 624  C++
server.exe!std::pair<unsigned int const,std::shared_ptr<User> >::~pair<unsigned int const,std::shared_ptr<User> >()   C++
server.exe!std::pair<unsigned int const,std::shared_ptr<User> >::`scalar deleting destructor'(unsigned int)    C++
server.exe!std::allocator<std::_Tree_node<std::pair<unsigned int const,std::shared_ptr<User> >,void *> >::destroy<std::pair<unsigned int const,std::shared_ptr<User> > >(std::pair<unsigned int const,std::shared_ptr<User> > * _Ptr) Line 624   C++
server.exe!std::allocator_traits<std::allocator<std::_Tree_node<std::pair<unsigned int const,void *> > >::destroy<std::pair<unsigned int const,std::shared_ptr<User> > >(std::allocator<std::_Tree_node<std::pair<unsigned int const,void *> > & _Al,std::pair<unsigned int const,std::shared_ptr<User> > * _Ptr) Line 758 C++
server.exe!std::_Wrap_alloc<std::allocator<std::_Tree_node<std::pair<unsigned int const,std::shared_ptr<User> > * _Ptr) Line 909    C++
server.exe!std::_Tree<std::_Tmap_traits<unsigned int,std::shared_ptr<User>,std::less<unsigned int>,std::allocator<std::pair<unsigned int const,std::shared_ptr<User> > >,0> >::_Erase(std::_Tree_node<std::pair<unsigned int const,void *> * _Rootnode) Line 2069 C++
server.exe!std::_Tree<std::_Tmap_traits<unsigned int,0> >::clear() Line 1538   C++
server.exe!std::_Tree<std::_Tmap_traits<unsigned int,0> >::erase(std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<std::pair<unsigned int const,std::shared_ptr<User> > > > > _First,std::_Tree_const_iterator<std::_Tree_val<std::_Tree_simple_types<std::pair<unsigned int const,std::shared_ptr<User> > > > > _Last) Line 1512    C++
server.exe!std::_Tree<std::_Tmap_traits<unsigned int,0> >::_Tidy() Line 2216   C++
server.exe!std::_Tree<std::_Tmap_traits<unsigned int,0> >::~_Tree<std::_Tmap_traits<unsigned int,0> >() Line 1190 C++
server.exe!std::map<unsigned int,std::shared_ptr<User> > > >::~map<unsigned int,std::shared_ptr<User> > > >() C++
server.exe!`dynamic atexit destructor for 'User::_usersListBySession''()    C++
msvcr110d.dll!doexit(int code,int quick,int retcaller) Line 584   C
msvcr110d.dll!exit(int code) Line 394   C
server.exe!__tmainCRTStartup() Line 549 C
server.exe!mainCRTStartup() Line 377    C

看起来所有其他线程都消失了.我想我可能在其他地方犯了一个错误.

感谢您清除信号功能的安全性.

编辑2：看起来像一个不相关的共享指针给我带来麻烦！我很高兴能看到一些好消息.

编辑3：一个完全不相关的问题导致崩溃.现在世界上的一切都很好.