2013-09-03 16:10:28 -04:00
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/*******************************************************************************
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Copyright(C) Jonas 'Sortie' Termansen 2013.
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2016-02-28 07:03:24 -05:00
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This file is part of the Sortix C Library.
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2013-09-03 16:10:28 -04:00
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2016-02-28 07:03:24 -05:00
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The Sortix C Library is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation, either version 3 of the License, or (at your
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2013-09-03 16:10:28 -04:00
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option) any later version.
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2016-02-28 07:03:24 -05:00
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The Sortix C Library is distributed in the hope that it will be useful, but
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2013-09-03 16:10:28 -04:00
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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2016-02-28 07:03:24 -05:00
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along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
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2013-09-03 16:10:28 -04:00
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2016-02-28 07:03:24 -05:00
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pthread/pthread_rwlock_tryrdlock.c
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2013-09-03 16:10:28 -04:00
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Attempts to acquire read access to a read-write lock.
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*******************************************************************************/
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#include <errno.h>
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#include <pthread.h>
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2016-02-28 07:03:24 -05:00
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int pthread_rwlock_tryrdlock(pthread_rwlock_t* rwlock)
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2013-09-03 16:10:28 -04:00
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{
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int ret;
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if ( (ret = pthread_mutex_trylock(&rwlock->request_mutex)) )
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2013-09-03 16:10:28 -04:00
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return errno = ret;
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while ( rwlock->num_writers || rwlock->pending_writers )
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{
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pthread_mutex_unlock(&rwlock->request_mutex);
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return errno = EBUSY;
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}
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rwlock->num_readers++;
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pthread_mutex_unlock(&rwlock->request_mutex);
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return 0;
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}
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