diff options
Diffstat (limited to 'lib/libc_r/uthread/uthread_queue.c')
| -rw-r--r-- | lib/libc_r/uthread/uthread_queue.c | 124 | 
1 files changed, 124 insertions, 0 deletions
| diff --git a/lib/libc_r/uthread/uthread_queue.c b/lib/libc_r/uthread/uthread_queue.c new file mode 100644 index 000000000000..5225ab8838e3 --- /dev/null +++ b/lib/libc_r/uthread/uthread_queue.c @@ -0,0 +1,124 @@ +/* + * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>. + * 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 John Birrell. + * 4. Neither the name of the author nor the names of any co-contributors + *    may be used to endorse or promote products derived from this software + *    without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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. + * + */ +#include <stdio.h> +#ifdef _THREAD_SAFE +#include <pthread.h> +#include "pthread_private.h" + +void +_thread_queue_init(struct pthread_queue * queue) +{ +	/* Initialise the pointers in the queue structure: */ +	queue->q_next = NULL; +	queue->q_last = NULL; +	queue->q_data = NULL; +	return; +} + +void +_thread_queue_enq(struct pthread_queue * queue, struct pthread * thread) +{ +	if (queue->q_last) { +		queue->q_last->qnxt = thread; +	} else { +		queue->q_next = thread; +	} +	queue->q_last = thread; +	thread->queue = queue; +	thread->qnxt = NULL; +	return; +} + +struct pthread * +_thread_queue_get(struct pthread_queue * queue) +{ +	/* Return the pointer to the next thread in the queue: */ +	return (queue->q_next); +} + +struct pthread * +_thread_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->qnxt)) { +			queue->q_last = NULL; +		} +		thread->queue = NULL; +		thread->qnxt = NULL; +	} +	return (thread); +} + +int +_thread_queue_remove(struct pthread_queue * queue, struct pthread * thread) +{ +	struct pthread **current = &(queue->q_next); +	struct pthread *prev = NULL; +	int             ret = -1; + +	while (*current) { +		if (*current == thread) { +			if ((*current)->qnxt) { +				*current = (*current)->qnxt; +			} else { +				queue->q_last = prev; +				*current = NULL; +			} +			ret = 0; +			break; +		} +		prev = *current; +		current = &((*current)->qnxt); +	} +	thread->queue = NULL; +	thread->qnxt = NULL; +	return (ret); +} + +int +pthread_llist_remove(struct pthread ** llist, struct pthread * thread) +{ +	while (*llist) { +		if (*llist == thread) { +			*llist = thread->qnxt; +			return (0); +		} +		llist = &(*llist)->qnxt; +	} +	return (-1); +} + +#endif | 
