diff options
Diffstat (limited to 'nptl/sysdeps/pthread/pthread_rwlock_rdlock.c')
| -rw-r--r-- | nptl/sysdeps/pthread/pthread_rwlock_rdlock.c | 95 |
1 files changed, 0 insertions, 95 deletions
diff --git a/nptl/sysdeps/pthread/pthread_rwlock_rdlock.c b/nptl/sysdeps/pthread/pthread_rwlock_rdlock.c deleted file mode 100644 index e225d7030d..0000000000 --- a/nptl/sysdeps/pthread/pthread_rwlock_rdlock.c +++ /dev/null @@ -1,95 +0,0 @@ -/* Copyright (C) 2003, 2004 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003. - - 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 <sysdep.h> -#include <lowlevellock.h> -#include <pthread.h> -#include <pthreadP.h> - - -/* Acquire read lock for RWLOCK. */ -int -__pthread_rwlock_rdlock (rwlock) - pthread_rwlock_t *rwlock; -{ - int result = 0; - - /* Make sure we are along. */ - lll_mutex_lock (rwlock->__data.__lock); - - while (1) - { - /* Get the rwlock if there is no writer... */ - if (rwlock->__data.__writer == 0 - /* ...and if either no writer is waiting or we prefer readers. */ - && (!rwlock->__data.__nr_writers_queued - || rwlock->__data.__flags == 0)) - { - /* Increment the reader counter. Avoid overflow. */ - if (__builtin_expect (++rwlock->__data.__nr_readers == 0, 0)) - { - /* Overflow on number of readers. */ - --rwlock->__data.__nr_readers; - result = EAGAIN; - } - - break; - } - - /* Make sure we are not holding the rwlock as a writer. This is - a deadlock situation we recognize and report. */ - if (__builtin_expect (rwlock->__data.__writer - == THREAD_GETMEM (THREAD_SELF, tid), 0)) - { - result = EDEADLK; - break; - } - - /* Remember that we are a reader. */ - if (__builtin_expect (++rwlock->__data.__nr_readers_queued == 0, 0)) - { - /* Overflow on number of queued readers. */ - --rwlock->__data.__nr_readers_queued; - result = EAGAIN; - break; - } - - int waitval = rwlock->__data.__readers_wakeup; - - /* Free the lock. */ - lll_mutex_unlock (rwlock->__data.__lock); - - /* Wait for the writer to finish. */ - lll_futex_wait (&rwlock->__data.__readers_wakeup, waitval); - - /* Get the lock. */ - lll_mutex_lock (rwlock->__data.__lock); - - --rwlock->__data.__nr_readers_queued; - } - - /* We are done, free the lock. */ - lll_mutex_unlock (rwlock->__data.__lock); - - return result; -} - -weak_alias (__pthread_rwlock_rdlock, pthread_rwlock_rdlock) -strong_alias (__pthread_rwlock_rdlock, __pthread_rwlock_rdlock_internal) |