Source to ipc/ipc_thread.c

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
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 * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
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 * Source License Version 1.0 (the 'License').  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource and read it before using
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 * 
 * The Original Code and all software distributed under the License are
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 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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 * @APPLE_LICENSE_HEADER_END@
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/*
 * Copyright (c) 1995, 1994, 1993, 1992, 1991, 1990  
 * Open Software Foundation, Inc. 
 *  
 * Permission to use, copy, modify, and distribute this software and 
 * its documentation for any purpose and without fee is hereby granted, 
 * provided that the above copyright notice appears in all copies and 
 * that both the copyright notice and this permission notice appear in 
 * supporting documentation, and that the name of ("OSF") or Open Software 
 * Foundation not be used in advertising or publicity pertaining to 
 * distribution of the software without specific, written prior permission. 
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 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
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 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
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 */
/*
 * OSF Research Institute MK6.1 (unencumbered) 1/31/1995
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  [email protected]
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 *	File:	ipc/ipc_thread.c
 *	Author:	Rich Draves
 *	Date:	1989
 *
 *	IPC operations on threads.
 */

#include <ipc/ipc_thread.h>

/*
 *	Routine:	ipc_thread_enqueue
 *	Purpose:
 *		Enqueue a thread.
 */

void
ipc_thread_enqueue(
	ipc_thread_queue_t	queue,
	ipc_thread_t		thread)
{
	ipc_thread_enqueue_macro(queue, thread);
}

/*
 *	Routine:	ipc_thread_dequeue
 *	Purpose:
 *		Dequeue and return a thread.
 */

ipc_thread_t
ipc_thread_dequeue(
	ipc_thread_queue_t	queue)
{
	ipc_thread_t first;

	first = ipc_thread_queue_first(queue);

	if (first != ITH_NULL)
		ipc_thread_rmqueue_first_macro(queue, first);

	return first;
}

/*
 *	Routine:	ipc_thread_rmqueue
 *	Purpose:
 *		Pull a thread out of a queue.
 */

void
ipc_thread_rmqueue(
	ipc_thread_queue_t	queue,
	ipc_thread_t		thread)
{
	ipc_thread_t next, prev;

	assert(queue->ithq_base != ITH_NULL);

	next = thread->ith_next;
	prev = thread->ith_prev;

	if (next == thread) {
		assert(prev == thread);
		assert(queue->ithq_base == thread);

		queue->ithq_base = ITH_NULL;
	} else {
		if (queue->ithq_base == thread)
			queue->ithq_base = next;

		next->ith_prev = prev;
		prev->ith_next = next;
		ipc_thread_links_init(thread);
	}
}