diff options
Diffstat (limited to 'libpthread/nptl/pthread_cond_destroy.c')
| -rw-r--r-- | libpthread/nptl/pthread_cond_destroy.c | 83 | 
1 files changed, 83 insertions, 0 deletions
| diff --git a/libpthread/nptl/pthread_cond_destroy.c b/libpthread/nptl/pthread_cond_destroy.c new file mode 100644 index 000000000..b67b53506 --- /dev/null +++ b/libpthread/nptl/pthread_cond_destroy.c @@ -0,0 +1,83 @@ +/* Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc. +   This file is part of the GNU C Library. +   Contributed by Ulrich Drepper <drepper@redhat.com>, 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 "pthreadP.h" + + +int +__pthread_cond_destroy ( +     pthread_cond_t *cond) +{ +  int pshared = (cond->__data.__mutex == (void *) ~0l) +		? LLL_SHARED : LLL_PRIVATE; + +  /* Make sure we are alone.  */ +  lll_lock (cond->__data.__lock, pshared); + +  if (cond->__data.__total_seq > cond->__data.__wakeup_seq) +    { +      /* If there are still some waiters which have not been +	 woken up, this is an application bug.  */ +      lll_unlock (cond->__data.__lock, pshared); +      return EBUSY; +    } + +  /* Tell pthread_cond_*wait that this condvar is being destroyed.  */ +  cond->__data.__total_seq = -1ULL; + +  /* If there are waiters which have been already signalled or +     broadcasted, but still are using the pthread_cond_t structure, +     pthread_cond_destroy needs to wait for them.  */ +  unsigned int nwaiters = cond->__data.__nwaiters; + +  if (nwaiters >= (1 << COND_NWAITERS_SHIFT)) +    { +      /* Wake everybody on the associated mutex in case there are +         threads that have been requeued to it. +         Without this, pthread_cond_destroy could block potentially +         for a long time or forever, as it would depend on other +         thread's using the mutex. +         When all threads waiting on the mutex are woken up, pthread_cond_wait +         only waits for threads to acquire and release the internal +         condvar lock.  */ +      if (cond->__data.__mutex != NULL +	  && cond->__data.__mutex != (void *) ~0l) +	{ +	  pthread_mutex_t *mut = (pthread_mutex_t *) cond->__data.__mutex; +	  lll_futex_wake (&mut->__data.__lock, INT_MAX, +			  PTHREAD_MUTEX_PSHARED (mut)); +	} + +      do +	{ +	  lll_unlock (cond->__data.__lock, pshared); + +	  lll_futex_wait (&cond->__data.__nwaiters, nwaiters, pshared); + +	  lll_lock (cond->__data.__lock, pshared); + +	  nwaiters = cond->__data.__nwaiters; +	} +      while (nwaiters >= (1 << COND_NWAITERS_SHIFT)); +    } + +  return 0; +} +weak_alias(__pthread_cond_destroy, pthread_cond_destroy) | 
