[LCP]Blocking malloc -- solved

[Hemant Mohan]

Finally I have solved the problem. It was another malloc call in the first 
thread that was corrupting the memory.

Thanks a lot for your inputs.
Hemant Mohan

On Tuesday 16 April 2002 11:09, Andrew Weaver wrote:
> Moi hemant, see attached source. Is this what you do (nearly) because it
> works just fine. Could it be that your "function1" exits and takes
> everything else with it?
>
>  <<malloctest.c.DOS>>
>
> > -----Original Message-----
> > From:   Hemant Mohan [SMTP:hemantm at pune.tcs.co.in]
> > Sent:   Thursday, April 11, 2002 8:50 AM
> > To:     linuxcprogramming at lists.linux.org.au
> > Subject:     [LCP]Blocking malloc
> >
> > Hi,
> >
> > I am stuck up in problem where the malloc is blocking.
> > I am programming in a multithreaded environment, using gcc-3.0.3 under
> > linux.
> > The thread related functions are from a user created library.
> >
> > The program structure is something like this:
> >
> > main()
> > {
> >     ....
> >     thread_create (function1, ...);
> >     ....
> > }
> >
> > function1(...)
> > {
> >     ...
> >     thread_create(function2, ...)
> > }
> >
> > function2(...)
> > {
> >     char* x = NULL;
> >     printf("First print\n");
> >     if((x = malloc(100*sizeof(char))) == NULL)
> >     {
> >          printf("second printf, malloc error\n");
> >          fflush(stdout);
> >          perror("malloc error");
> >     }
> >     printf("third printf\n");
> >     fflush(stdout);
> >     ....
> > }
> >
> > My problem is
> > When the program is run we reach the function2 and the first print
>
> message
>
> > is
> > displayed. However after that the program blocks. Neither I get the
>
> second
>
> > print message nor the third one. The program doesn't proceed further.
>
> Even
>
> > there is no error message from the perror.  Normally, if the malloc fails
> > then it should return a NULL and we should get the second printf and the
> > malloc error. Else, if the malloc call is successful then the third print
> > should be displayed.
> > Where am I going wrong ?  I couldn't find any documentation indicating
>
> any
>
> > condition where malloc can block.
> >
> > Can anyone please help .
> >
> > Thanks,
> > Hemant
> >
> > _______________________________________________
> > This is the Linux C Programming List
> >
> > :  http://lists.linux.org.au/listinfo/linuxcprogramming List
>
> (See attached file: malloctest.c.DOS)