Re: PTHREAD_MUTEX_DEFAULT different for cygwin v.s. linux.

[Peter Rehley <peter at rehley dot net>]

On Jun 9, 2005, at 8:57 AM, Christopher Faylor wrote:

> On Wed, Jun 08, 2005 at 03:29:46PM -0700, Peter Rehley wrote:
> > On Jun 8, 2005, at 2:59 PM, Thomas E. Zerucha wrote:
> >
> > > I have a problem similar to that of:
> > >
> > > http://sourceware.org/ml/cygwin/2005-05/msg01400.html
> > >
> > > I have an old system that I'm trying to port that uses pthreads, but
> > > doesn't set the attribute, and a non-owner thread will destroy the
> > > thread in a deallocate routine, but this won't happen (it won't
> > > actually destroy the thread).
> > >
> > > The problem is that (in pthread.h) PTHREAD_MUTEX_DEFAULT is .._NORMAL
> > > on linux, the system was originally written for.  It works but
> > > eventually dies when it runs out of threads or mutexes or something
> > > since it can't recycle.  PTHREAD_MUTEX_DEFAULT is .._ERRORCHECK on
> > > cygwin.
> > >
> > > It would be painful to add a whole section to create an attribute
> > > structure just to set this to be the same as linux.
> >
> > If you look at the test case you will see a line that says
> > mutex=PTHREAD_MUTEX_INITIALIZER;
> >
> > This causes the program to use the default (ERRORCHECK) mutex.  To get
> > a normal mutex, you can use mutex=PTHREAD_NORMAL_MUTEX_INITIALIZER_NP;
> >
> > However, in the test case when NORMAL is used, the mutex never gets
> > unlocked because the signal SIG_CHLD doesn't get to the parent.
>
> FWIW, I've changed the default for PTHREAD_MUTEX_INITIALIZER to
> PTHREAD_NORMAL_MUTEX_INITIALIZER_NP in CVS.  Last night I also tried to
> implement handling for interrupting mutexes based on Corinna's
> explanation of what your patch did.
Shouldn't PTHREAD_MUTEX_DEFAULT be PTHREAD_MUTEX_NORMAL?

> Both of these changes are in the current snapshot.
And the pthread_mutex_lock is still waiting forever...doesn't process 
the signal.  Looking at the code I think that the pthread_mutex::_lock 
function should be using the cancelable_wait routine in place of the 
WaitForSingleObject.


> cgf
>
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Enjoy,
Peter
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