waitq.h revision c97ad5cdc75eb73e3cc38542ca3ba783574b0a7a
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_WAITQ_H
#define _SYS_WAITQ_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
#ifdef _KERNEL
#include <sys/types.h>
#include <sys/machlock.h>
#include <sys/thread.h>
typedef struct waitq {
disp_lock_t wq_lock; /* protects all fields */
kthread_t *wq_first; /* first thread on the queue */
int wq_count; /* number of threads on the queue */
boolean_t wq_blocked; /* True if threads can't be enqueued */
} waitq_t;
extern void waitq_init(waitq_t *);
extern void waitq_fini(waitq_t *);
/*
* Place the thread on the wait queue. An attempt to enqueue a thread onto a
* blocked queue fails and returns zero. Successful enqueue returns non-zero
* value.
*/
extern int waitq_enqueue(waitq_t *, kthread_t *);
/*
* Take thread off its wait queue and make it runnable.
*/
extern void waitq_setrun(kthread_t *t);
/*
* Change priority for the thread on wait queue.
*/
extern void waitq_change_pri(kthread_t *, pri_t);
/*
* Take the first thread off the wait queue and make it runnable.
*/
extern void waitq_runone(waitq_t *);
/*
* Return True if there are no threads on the queue.
*/
extern boolean_t waitq_isempty(waitq_t *);
/*
* Prevent and allow placing new threads on wait queue.
*/
extern void waitq_block(waitq_t *);
extern void waitq_unblock(waitq_t *);
#endif /* _KERNEL */
#ifdef __cplusplus
}
#endif
#endif /* _SYS_WAITQ_H */