[Boost-users] question about boost::thread

Subject: [Boost-users] question about boost::thread
From: PingShan Li (lipingshan72_at_[hidden])
Date: 2008-09-12 18:06:39

Here is my test program using boost::thread. I would expect this program to
crash inside FunctionA because m_ClassA is no longer available.

Can anybody help me to understand why it does not crash? thank you.

[root_at_localhost]# uname -a
Linux localhost.localdomain 2.6.9-22.EL #1 Mon Sep 19 18:20:28 EDT 2005 i686
i686 i386 GNU/Linux
[root_at_localhost]# g++ --version
g++ (GCC) 3.4.4 20050721 (Red Hat 3.4.4-2)
Copyright (C) 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 g++ -I/opt/third_party_libraries/boost_1_33_1
-L/opt/third_party_libraries/boost_1_33_1/stage/lib -lboost_thread-gcc-mt
main.cpp -o test

#include <boost/bind.hpp>
#include <boost/thread.hpp>
#include <iostream>

void SleepTime( int a )
{
  boost::xtime xt;
  boost::xtime_get( &xt, boost::TIME_UTC );
  xt.sec += a;
  boost::thread::sleep( xt );
}

class ClassA
{
  public:

    ClassA( int member ) : m_member( member )
    {
      std::cout << "ClassA constructor: " << m_member << std::endl;
    }

    virtual ~ClassA( )
    {
      std::cout << "ClassA destructor: " << m_member << std::endl;
    }

    void SetMember( int a )
    {
      m_member = a;
    }

    int GetMember() const
    {
      return m_member;
    }

  private:

    int m_member;
};

class TestClass
{
  public:

    TestClass( )
      : m_ClassA( 0 )

    {
      std::cout << "TestClass constructor: " << m_ClassA.GetMember() <<
std::endl;
    }

    virtual ~TestClass( )
    {
      std::cout << "TestClass destructor: " << m_ClassA.GetMember() <<
std::endl;
    }

    void RunThreadFunction()
    {
      std::cout << "RunThreadFunction start" << std::endl;
      boost::thread thr( boost::bind( &TestClass::ThreadFunction, this )
);
      std::cout << "RunThreadFunction end" << std::endl;
    }

    void ThreadFunction( )
    {
      std::cout << "ThreadFunction start" << std::endl;
      m_ClassA.SetMember( 5 );
      SleepTime( 5 );
      FunctionA( );
      return;

    }

    void FunctionA( )
    {
      std::cout << "Inside FunctionA: " << m_ClassA.GetMember() <<
std::endl;
    }

  private:

    ClassA m_ClassA;
};

int main()
{
  {
    TestClass a;
    a.RunThreadFunction();
  }

  std::cout << "main wait" << std::endl;
  SleepTime( 10 );

  return 0;
}