Re: [Boost-users] [thread] : pause/resume thread

Subject: Re: [Boost-users] [thread] : pause/resume thread
From: bit bit (g_rambot_at_[hidden])
Date: 2011-04-15 09:22:51

remove fptr(this);
You call qthread's Execute() from your main thread and you are waiting on a condition variable.

> To: boost-users_at_[hidden]
> From: Viatcheslav.Sysoltsev_at_[hidden]
> Date: Fri, 15 Apr 2011 15:18:06 +0200
> Subject: Re: [Boost-users] [thread] : pause/resume thread
> 
> > Hi All, I have just started learning boost. I want my thread to support
> > following functions
> > Pause();
> > Resume();
> > Stop();.
> > I have come up with following code, which ends up as dead lock. Can some  
> > one
> > please guide me as how to achieve the desired functionality.
> > Would really appreciate any help.
> > Thanks.
> > Kaz
> > class qthread
> > {
> > public:
> >     boost::thread* mThread;
> >     boost::condition_variable mCond;
> >     boost::mutex mMutex;
> >     bool mExit;
> >     qthread(): mExit(false)
> >     {
> >         // create function pointer to local Execute function
> >         boost::function<void (qthread*)> fptr = &qthread::Execute;
> >         fptr(this);
> you call Execute() here in the main thread
> 
> 
> >         // pass on function pointer along with this reference to boost
> > thread
> >         boost::thread th0( fptr, this);
> >         // assign temp thread to local variable
> >         mThread = &th0;
> >     }
> and now your th0 is destroyed leaving invalid pointer. Strange, I thought  
> gcc has already learned to warn about such stuff, but I don't get any  
> warning with gcc 4.3.2 here even with -Wall
> 
> 
> 
> >         mCond.wait(lock);       //<< DEAD LOCK
> It's not a dead lock, don't swear with so scary words ;). If you'd debug  
> the program, you see you are still having only one thread by the time.
> 
> -- Slava
> 
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