RE: [LI] Please Respond

["Guruprasad, Mahendrakar V (IE10)" <GuruprasadM@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Hi,
	Thanks for your reply. I am confused with your 1 st observation. My
intention in that program is 
	to cancel the created threads & not the calling thread. If you do
pthread_exit(PTHREAD_CANCELED)
	then the calling thread will be cancelled. I don't want that. I want
to cancel the created threads
	your 3rd observation is true. That is what I am emphasizing. If a
threads waiting on same mutex/cond variable
	are cancelled, & then the resources held by them can't be
deallocated. If we deallocate ,
	we will be screwed up in RedHat5.1, but not in RedHat6.0
Bye

> -----Original Message-----
> From:	sudheer@xxxxxxxxxxxxx [SMTP:sudheer@xxxxxxxxxxxxx]
> Sent:	Thursday, September 23, 1999 3:44 PM
> To:	Guruprasad, Mahendrakar  V (IE10)
> Subject:	RE: [LI] Please Respond
> 
> Hi ,
> 
> I'm using SuSE-5.1, and i don't know much about programming using
> threads. Still, i would like to send some of my observations in
> hope that it may be useful(unless a guru comes out with all
> possible reasons) 
> 
> 1) In your program you use the flag "PTHREAD_CANCEL_ASYNCHRONOUS" for
> immediate consideration of cancel request. Hence, instead of calling
> pthread_cancel(pThread[i]); if pthread_exit(PTHREAD_CANCELED); is used,
> it doesn't dump core, also it's cancelling the calling thread.
> 
> 2) When i tried PTHREAD_CANCEL_DEFERRED, in place of 
> PTHREAD_CANCEL_ASYNCHRONOUS, then also the program didn't crash.
> 
> 3) Everythings seems to be hanging around the mutex lock.
> 
> sudheer
> 
> 
> On Thu, 23 Sep 1999, Guruprasad, Mahendrakar  V (IE10) wrote:
> 
> > Hi,
> > 	Thanks. at last I got a helping hand. This following code will cause
> > 
> > 
> > #include <stdio.h>
> > #include <pthread.h>
> > #include <stdlib.h>
> > pthread_mutex_t mutex=PTHREAD_MUTEX_INITIALIZER;
> > void * thread(void *buf)
> > {
> >         pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS,NULL);
> >         pthread_mutex_lock(&mutex);
> >         while(1);
> > }
> > void main(void)
> > {
> > void fun(void);
> >         for(;;)
> >                 fun();
> > }
> >  
> > void fun(void)
> > {
> >         pthread_t *pThread;
> >         int i;
> >         int nCount=6;
> >         int wCounter = 0;
> >         pThread=(pthread_t *)malloc(nCount*sizeof(pthread_t));
> >         for(;;)
> >         {
> >                 wCounter++;
> >                 if (wCounter % 100 == 0)
> >                   printf("Starting Threads Loop #%d.\n", wCounter);
> >  
> >                 for(i=0;i<nCount;i++)
> >                         pthread_create(&pThread[i],NULL,thread,NULL);
> >  
> >                 for(i=0;i<nCount;i++)
> >                 {
> >                         pthread_cancel(pThread[i]);
> >                 //      pthread_join(pThread[i],NULL);
> >                         pthread_detach(pThread[i]);
> >                 }
> >         }
> > }
> > 
> > 
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