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Diffstat (limited to 'mit-pthreads/pthreads/queue.c')
| -rw-r--r-- | mit-pthreads/pthreads/queue.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/mit-pthreads/pthreads/queue.c b/mit-pthreads/pthreads/queue.c new file mode 100644 index 00000000000..c33774bf4dd --- /dev/null +++ b/mit-pthreads/pthreads/queue.c @@ -0,0 +1,143 @@ +/* ==== queue.c ============================================================ + * Copyright (c) 1993, 1994 by Chris Provenzano, proven@mit.edu + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Chris Provenzano. + * 4. The name of Chris Provenzano may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL CHRIS PROVENZANO BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Description : Queue functions. + * + * 1.00 93/07/15 proven + * -Started coding this file. + */ + +#ifndef lint +static const char rcsid[] = "$Id$"; +#endif + +#include <pthread.h> + +/* + * All routines in this file assume that the queue has been appropriatly + * locked. + */ + +/* ========================================================================== + * pthread_queue_init() + */ +void pthread_queue_init(struct pthread_queue *queue) +{ + queue->q_next = NULL; + queue->q_last = NULL; + queue->q_data = NULL; +} + +/* ========================================================================== + * pthread_queue_enq() + */ +void pthread_queue_enq(struct pthread_queue *queue, struct pthread *thread) +{ + if (queue->q_last) { + queue->q_last->next = thread; + } else { + queue->q_next = thread; + } + queue->q_last = thread; + thread->queue = queue; + thread->next = NULL; + +} + +/* ========================================================================== + * pthread_queue_get() + */ +struct pthread *pthread_queue_get(struct pthread_queue *queue) +{ + return(queue->q_next); +} + +/* ========================================================================== + * pthread_queue_deq() + */ +struct pthread *pthread_queue_deq(struct pthread_queue *queue) +{ + struct pthread *thread = NULL; + + if (queue->q_next) { + thread = queue->q_next; + if (!(queue->q_next = queue->q_next->next)) { + queue->q_last = NULL; + } + thread->queue = NULL; + thread->next = NULL; + } + return(thread); +} + +/* ========================================================================== + * pthread_queue_remove() + */ +int pthread_queue_remove(struct pthread_queue *queue, struct pthread *thread) +{ + struct pthread **current = &(queue->q_next); + struct pthread *prev = NULL; + int ret = NOTOK; + + while (*current) { + if (*current == thread) { + if ((*current)->next) { + *current = (*current)->next; + } else { + queue->q_last = prev; + *current = NULL; + } + thread->queue = NULL; + thread->next = NULL; + ret = OK; + break; + } + prev = *current; + current = &((*current)->next); + } + return(ret); +} + +/* ========================================================================== + * pthread_llist_remove() + */ +int pthread_llist_remove(struct pthread **llist, struct pthread *thread) +{ + while (*llist) { + if (*llist == thread) { + *llist = thread->next; + return(OK); + } + llist = &(*llist)->next; + } + return(NOTOK); +} + |