diff options
author | aunsane <aunsane@gmail.com> | 2017-12-15 01:05:56 +0300 |
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committer | aunsane <aunsane@gmail.com> | 2017-12-15 01:05:56 +0300 |
commit | e124aa3611f38573898aa79c6eabe77bc874e58f (patch) | |
tree | 819464260f758bbc002b23c0c8a77f93751dcb42 /libs/pthreads/src/pthread_rwlock_rdlock.c | |
parent | bbd9647d47f20d10b39570def918a0ac68c305c9 (diff) |
preparing to build tox from sources
Diffstat (limited to 'libs/pthreads/src/pthread_rwlock_rdlock.c')
-rw-r--r-- | libs/pthreads/src/pthread_rwlock_rdlock.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/libs/pthreads/src/pthread_rwlock_rdlock.c b/libs/pthreads/src/pthread_rwlock_rdlock.c new file mode 100644 index 0000000000..91e180835e --- /dev/null +++ b/libs/pthreads/src/pthread_rwlock_rdlock.c @@ -0,0 +1,102 @@ +/* + * pthread_rwlock_rdlock.c + * + * Description: + * This translation unit implements read/write lock primitives. + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2005 Pthreads-win32 contributors + * + * Contact Email: rpj@callisto.canberra.edu.au + * + * The current list of contributors is contained + * in the file CONTRIBUTORS included with the source + * code distribution. The list can also be seen at the + * following World Wide Web location: + * http://sources.redhat.com/pthreads-win32/contributors.html + * + * This 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 of the License, or (at your option) any later version. + * + * This 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 this library in the file COPYING.LIB; + * if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include <limits.h> + +#include "pthread.h" +#include "implement.h" + +int +pthread_rwlock_rdlock (pthread_rwlock_t * rwlock) +{ + int result; + pthread_rwlock_t rwl; + + if (rwlock == NULL || *rwlock == NULL) + { + return EINVAL; + } + + /* + * We do a quick check to see if we need to do more work + * to initialise a static rwlock. We check + * again inside the guarded section of ptw32_rwlock_check_need_init() + * to avoid race conditions. + */ + if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) + { + result = ptw32_rwlock_check_need_init (rwlock); + + if (result != 0 && result != EBUSY) + { + return result; + } + } + + rwl = *rwlock; + + if (rwl->nMagic != PTW32_RWLOCK_MAGIC) + { + return EINVAL; + } + + if ((result = pthread_mutex_lock (&(rwl->mtxExclusiveAccess))) != 0) + { + return result; + } + + if (++rwl->nSharedAccessCount == INT_MAX) + { + if ((result = + pthread_mutex_lock (&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock (&(rwl->mtxExclusiveAccess)); + return result; + } + + rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount; + rwl->nCompletedSharedAccessCount = 0; + + if ((result = + pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted))) != 0) + { + (void) pthread_mutex_unlock (&(rwl->mtxExclusiveAccess)); + return result; + } + } + + return (pthread_mutex_unlock (&(rwl->mtxExclusiveAccess))); +} |