我目前正在编写一个使用 boost 线程的 DLL。我在使用 boost::thread::interrupt() 和捕获 thread_interrupted 异常时遇到了问题。对于某些中断点,中断被抛出并捕获在线程中,而对于其他中断点,则在调用 thread.interrupt() 的地方抛出中断。为什么会这样?我写了一个基本的例子来说明我的观点,它在这篇文章的底部
该程序启动一个线程,该线程使用其中一个工作函数,每个工作函数中都有不同的中断点。当用户按下回车键时,线程被中断,程序关闭。在打印每条语句之前,都会打印线程 ID,以便我们可以看到发生了什么。
我期待这样的事情:
13c4 main thread
790 worker thread
790 thread iteration 1 Press Enter to stop
790 thread iteration 2 Press Enter to stop
790 thread iteration 3 Press Enter to stop
790 Thread is stopped in ThreadFunction
13c4 main: thread ended
Process returned 0 (0x0) execution time : 0.200 s
Press any key to continue.
主线程与工作线程并行运行的地方。当用户按下回车键时,中断在主线程中被调用,但在工作线程中被捕获。然后线程被销毁。然后主线程继续,程序退出。
我在尝试过的所有中断点(interrupt_point() 除外)中看到的是中断被捕获在主线程中,并且似乎它是继续执行主线程的工作线程。像这样:
1364 main thread
964 worker thread
964 thread iteration 1 Press Enter to stop
964 thread iteration 2 Press Enter to stop
964 thread iteration 3 Press Enter to stop
964 Thread is joined
964 main: thread ended
Process returned 0 (0x0) execution time : 1.510 s
Press any key to continue.
这是什么原因造成的?例如,在使用条件变量时,如何在工作函数中捕获中断?我在某个地方犯了错误吗?
我的代码:
#define BOOST_THREAD_USE_LIB 1
#define BOOST_SYSTEM_NO_DEPRECATED 1
#define _WIN32_WINNT 0x0501
#define WINVER 0x0501
#include <boost/thread.hpp>
#include <iostream>
using namespace std;
void ThreadFunctionSleep()
{
cout << boost::this_thread::get_id() << " worker thread " << endl;
int counter = 0;
while(1)
{
cout << boost::this_thread::get_id() << " thread iteration " << ++counter << " Press Enter to stop" << endl;
try
{
boost::this_thread::sleep(boost::posix_time::milliseconds(5000));
}
catch(boost::thread_interrupted&)
{
cout << boost::this_thread::get_id() << " Thread is stopped in ThreadFunction " << endl;
return;
}
}
}
void ThreadFunctionSleep2()
{
cout << boost::this_thread::get_id() << " worker thread " << endl;
int counter = 0;
try
{
cout << boost::this_thread::get_id() << " thread iteration " << ++counter << " Press Enter to stop" << endl;
while(1)
{
boost::this_thread::sleep(boost::posix_time::milliseconds(5000));
}
}
catch(boost::thread_interrupted&)
{
cout << boost::this_thread::get_id() << " Thread is stopped in ThreadFunction " << endl;
return;
}
}
void ThreadFunctionInterruptionPoint()
{
cout << boost::this_thread::get_id() << " worker thread " << endl;
int counter = 0;
while(1)
{
cout << boost::this_thread::get_id() << " thread iteration " << ++counter << " Press Enter to stop" << endl;
try
{
boost::this_thread::interruption_point();
}
catch(boost::thread_interrupted&)
{
cout << boost::this_thread::get_id() << " Thread is stopped in ThreadFunction " << endl;
return;
}
}
}
bool myPredicate()
{
return false;
}
boost::condition_variable full;
boost::condition_variable empty;
boost::mutex fullMut;
boost::mutex emptyMut;
void waitedConditionVariable()
{
try
{
while(1)
{
boost::system_time const timeout=boost::get_system_time()+ boost::posix_time::milliseconds(1000);
boost::unique_lock<boost::mutex> lock(fullMut);
std::cout << boost::this_thread::get_id()<< " waiting for condition variable or for timeout" << std::endl;
if (full.timed_wait(lock, timeout, myPredicate))
{
std::cout << boost::this_thread::get_id()<< " condition variable signalled " << std::endl;
}
else
{
std::cout << boost::this_thread::get_id()<< " condition variable timeout. " << std::endl;
}
}
}
catch(boost::thread_interrupted & )
{
std::cout<< boost::this_thread::get_id() << " waitedConditionVariable thread_interrupted " << std::endl;
return;
}
catch (std::exception& e)
{
std::cerr << boost::this_thread::get_id()<< " waitedConditionVariable Thread "
<< " caught std::exception" << e.what() << std::endl;
return;
}
catch(...)
{
std::cout<< boost::this_thread::get_id() << " waitedConditionVariable other" << std::endl;
return;
}
}
void waitedConditionVariable2()
{
while(1)
{
try
{
boost::system_time const timeout=boost::get_system_time()+ boost::posix_time::milliseconds(1000);
boost::unique_lock<boost::mutex> lock(fullMut);
std::cout << boost::this_thread::get_id()<< " waiting for condition variable or for timeout" << std::endl;
if (full.timed_wait(lock, timeout, myPredicate))
{
std::cout << boost::this_thread::get_id()<< " condition variable signalled " << std::endl;
}
else
{
std::cout << boost::this_thread::get_id()<< " condition variable timeout. " << std::endl;
}
}
catch(boost::thread_interrupted & )
{
std::cout<< boost::this_thread::get_id() << " waitedConditionVariable thread_interrupted " << std::endl;
return;
}
catch (std::exception& e)
{
std::cerr << boost::this_thread::get_id()<< " waitedConditionVariable Thread "
<< " caught std::exception" << e.what() << std::endl;
return;
}
catch(...)
{
std::cout<< boost::this_thread::get_id() << " waitedConditionVariable other" << std::endl;
return;
}
}
}
void normalConditionVariable()
{
try
{
boost::unique_lock<boost::mutex> lock(fullMut);
while(1)
{
std::cout << boost::this_thread::get_id()<< " waiting for condition variable " << std::endl;
full.wait(lock);
std::cout << boost::this_thread::get_id()<< " wait done " << std::endl;
}
}
catch(boost::thread_interrupted & )
{
std::cout<< boost::this_thread::get_id() << " normalConditionVariable thread_interrupted " << std::endl;
return;
}
catch (std::exception& e)
{
std::cerr << boost::this_thread::get_id()<< " normalConditionVariable Thread "
<< " caught std::exception" << e.what() << std::endl;
return;
}
catch(...)
{
std::cout<< boost::this_thread::get_id() << " normalConditionVariable other" << std::endl;
return;
}
}
void normalConditionVariable2()
{
while(1)
{
boost::unique_lock<boost::mutex> lock(fullMut);
try
{
std::cout << boost::this_thread::get_id()<< " waiting for condition variable " << std::endl;
full.wait(lock);
std::cout << boost::this_thread::get_id()<< " wait done " << std::endl;
}
catch(boost::thread_interrupted & )
{
std::cout<< boost::this_thread::get_id() << " normalConditionVariable thread_interrupted " << std::endl;
return;
}
catch (std::exception& e)
{
std::cerr << boost::this_thread::get_id()<< " normalConditionVariable Thread "
<< " caught std::exception" << e.what() << std::endl;
return;
}
catch(...)
{
std::cout<< boost::this_thread::get_id() << " normalConditionVariable other" << std::endl;
return;
}
}
}
int main()
{
cout << boost::this_thread::get_id() << " main thread " << endl;
// Start thread
//use thes functions:
// ThreadFunctionSleep
// ThreadFunctionSleep2
//ThreadFunctionInterruptionPoint
//ThreadFunctionInterruptionPoint2
// waitedConditionVariable
// waitedConditionVariable2
// normalConditionVariable
// normalConditionVariable2
boost::thread t(&waitedConditionVariable2);
// Wait for Enter
char ch;
cin.get(ch);
// Ask thread to stop
try
{
t.interrupt();
}
catch(boost::thread_interrupted&)
{
cout << boost::this_thread::get_id() << " Thread is stopped" << endl;
}
// Join - wait when thread actually exits
try
{
t.join();
}
catch(boost::thread_interrupted&)
{
cout << boost::this_thread::get_id() << " Thread is joined" << endl;
}
catch(...){
cout << boost::this_thread::get_id() << " other exception" << endl;
}
cout << boost::this_thread::get_id() << " main: thread ended" << endl;
return 0;
}
我正在使用 boost 1.53.0 和 MinGW 4.4.1。我正在为 boost::thread 和 boost::system 使用运行时链接静态多线程库
谢谢你的帮助