Kevin Atkinson wrote:
>
> On Thu, 20 Feb 2003, Alexander Terekhov wrote:
>
> > > I have changed the definition to:
> > >
> > > #ifdef FAST_MUTEX_INIT_DESTROY
> > ^^^^^^^
> >
> > > static const pthread_mutex_t MUTEX_INIT = PTHREAD_MUTEX_INITIALIZER;
> >
> > Uhmm. What does your "fast destruction" do? Well, looking at the code
> > you've posted, it does nothing... and that's the "fastest" way to leak.
>
> It depends on the implementation. On some, including linux, there is
> nothing to free.
But that might change overnight [on the next start, I mean]... and even
without any recompiles (rebuilds) on the part of your clients, Kevin.
<illustration source=nptl-0.24/nptl/old_pthread_cond_wait.c>
/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <[EMAIL PROTECTED]>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <stdlib.h>
#include "pthreadP.h"
#include <atomic.h>
#include <shlib-compat.h>
#if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2)
int
__pthread_cond_wait_2_0 (cond, mutex)
pthread_cond_2_0_t *cond;
pthread_mutex_t *mutex;
{
if (cond->cond == NULL)
{
pthread_cond_t *newcond;
#if LLL_MUTEX_LOCK_INITIALIZER == 0
newcond = (pthread_cond_t *) calloc (sizeof (pthread_cond_t), 1);
if (newcond == NULL)
return ENOMEM;
#else
newcond = (pthread_cond_t *) malloc (sizeof (pthread_cond_t));
if (newcond == NULL)
return ENOMEM;
/* Initialize the condvar. */
(void) pthread_cond_init (newcond, NULL);
#endif
if (atomic_compare_and_exchange_acq (&cond->cond, newcond, NULL) != 0)
/* Somebody else just initialized the condvar. */
free (newcond);
}
return __pthread_cond_wait (cond->cond, mutex);
}
compat_symbol (libpthread, __pthread_cond_wait_2_0, pthread_cond_wait,
GLIBC_2_0);
#endif
</illustration>
This is from the latest NPTL code drop. BTW, it seems that it's broken
with respect to memory visibility on MPs with relaxed memory ordering,
but never mind. ;-)
regards,
alexander.
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