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我正在尝试使用 C++11 中的线程库编写多线程软件。网上找的一些基础教程可以按预期编译运行。但是我自己的应用程序分成类总是抛出异常。

谁能告诉我代码的哪一部分应该修复，好吗？

$ clang++ -std=c++11 -stdlib=libc++ BaseInterface.cxx -c -o BaseInterface.o
$ clang++ -std=c++11 -stdlib=libc++ SocketReceiver.cxx -c -o SocketReceiver.o
$ clang++ -std=c++11 -stdlib=libc++ main.cxx -c -o main.o
$ clang++ -std=c++11 -stdlib=libc++ main.o BaseInterface.o SocketReceiver.o -o main
$ gdb main  
(gdb) run
Starting program: /Users/oxon/test/main 
Reading symbols for shared libraries ++............................ done
libc++abi.dylib: terminate called throwing an exception

Program received signal SIGABRT, Aborted.
[Switching to process 859 thread 0x40b]
0x00007fff88df8212 in __pthread_kill ()
(gdb) bt
#0  0x00007fff88df8212 in __pthread_kill ()
#1  0x00007fff8bc85af4 in pthread_kill ()
#2  0x00007fff8bcc9dce in abort ()
#3  0x00007fff894d3a17 in abort_message ()
#4  0x00007fff894d13c6 in default_terminate ()
#5  0x00007fff89874887 in _objc_terminate ()
#6  0x00007fff894d13f5 in safe_handler_caller ()
#7  0x00007fff894d1450 in std::terminate ()
#8  0x00007fff894d25b7 in __cxa_throw ()
#9  0x00007fff8a9ba3b9 in std::__1::thread::join ()
#10 0x0000000100000cf0 in SocketReceiver::Receive ()
#11 0x0000000100000c6d in SocketReceiver::DoReceive ()
#12 0x0000000100001593 in _ZNSt3__114__thread_proxyINS_5tupleIJPFPvS2_ES2_EEEEES2_S2_ ()
#13 0x00007fff8bc84742 in _pthread_start ()
#14 0x00007fff8bc71181 in thread_start ()

这是 OS X 10.8 上的结果。带有 GCC 4.4 的 Scientific Linux 6 也给出了类似的结果。

= BaseInterface.h =

#ifndef BASE_INTERFACE_H
#define BASE_INTERFACE_H

#include "SocketReceiver.h"

class BaseInterface
{
private:
  SocketReceiver*    fReceiver;

public:
  BaseInterface();
  virtual ~BaseInterface();

  virtual void Close();
  virtual void Open();
;

#endif

= BaseInterface.cxx =

#include <iostream>

#include <string.h>
#include <unistd.h>

#include "BaseInterface.h"

BaseInterface::BaseInterface()
{
  fReceiver = new SocketReceiver(this);
}

//______________________________________________________________________________
BaseInterface::~BaseInterface()
{
  Close();
  delete fReceiver;
  fReceiver = 0;
}

//______________________________________________________________________________
void BaseInterface::Close()
{
  fReceiver->Stop();
  usleep(10000);

  while(fReceiver->IsRunning()){
    usleep(10000);
  } // while
}

//______________________________________________________________________________
void BaseInterface::Open()
{
  fReceiver->Start();

}

= SocketReceiver.h =

#ifndef SOCKET_RECEIVER_H
#define SOCKET_RECEIVER_H

#include <thread>
#include <mutex>

class BaseInterface;

class SocketReceiver
{
private:
  BaseInterface*             fInterface;
  bool                       fIsRunning;
  std::mutex                 fMutex;
  bool                       fStop;
  std::thread*               fThread;

public:
  SocketReceiver(BaseInterface* interface = 0);
  virtual ~SocketReceiver();

  bool             IsRunning() const {return fThread ? true : false;}
  static void*     DoReceive(void* arg);
  void             Receive();
  void             Start();
  void             Stop();
};

#endif

= SocketReceiver.cxx =

#include <iostream>
#include <thread>
#include <unistd.h>

#include "BaseInterface.h"
#include "SocketReceiver.h"

SocketReceiver::SocketReceiver(BaseInterface* interface)
{
  fInterface = interface;
  fStop = true;
  fThread = 0;
}

//______________________________________________________________________________
SocketReceiver::~SocketReceiver()
{
}

//______________________________________________________________________________
void* SocketReceiver::DoReceive(void* arg)
{
  SocketReceiver* receiver = (SocketReceiver*)arg;
  receiver->Receive();

  return 0;
}

//______________________________________________________________________________
void SocketReceiver::Receive()
{
  while(not fStop){
    fMutex.lock();
    usleep(10000);
    fMutex.unlock();
  } // while

  fThread->join();

  delete fThread;
  fThread = 0;
}

//______________________________________________________________________________
void SocketReceiver::Start()
{
  fStop = false;
  fThread  = new std::thread(DoReceive, (void*)this);
}

//______________________________________________________________________________
void SocketReceiver::Stop()
{
  fStop = true;
}

= main.cxx =

#include "BaseInterface.h"

int main()
{
  BaseInterface interface;
  interface.Open();
  interface.Close();

  return 0;
}
4

2 回答 2

4

您正在加入线程本身。join在父线程中调用，例如在SocketReceiver::Stop.

当join被调用时，它会清理底层数据。如果你在你正在运行的线程中调用它，那么当线程仍然需要它时，这些数据将被删除。

于 2013-03-07T09:17:58.453 回答
4

如果由 a 运行的函数std::thread通过和异常退出，std::terminate则将被调用。

std::thread::join()如果在同一个线程中调用，则指定抛出std::system_error错误代码，即线程无法加入自身。因此，您尝试使线程加入本身会导致异常终止进程。线程不能加入自己，加入被定义为“等待线程完成”所以显然不能由线程本身完成，它会阻塞等待自己完成，这在调用完成之前不会发生，这可以直到线程完成才发生，直到调用完成才发生……你能看到这是怎么回事吗？resource_deadlock_would_occurjoin()join()join()

还有你为什么要这样做？

fThread  = new std::thread(DoReceive, (void*)this);

std::thread不是pthread_create，你不需要通过它void*，只需摆脱DoReceive并调用：

fThread  = new std::thread(&SocketReceiver::Receive, this);

为什么你std::thread被分配了new？这也不是必需的，您可以使用std::thread成员并使用joinable()来检查它是否处于活动状态，而不是检查指针是否为非空。

于 2013-03-07T09:24:49.347 回答