[apple/xnu.git] / osfmk / mach / flipc_locks.h

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 * 
 */
/*
 * HISTORY
 * 
 * Revision 1.1.1.1  1998/09/22 21:05:30  wsanchez
 * Import of Mac OS X kernel (~semeria)
 *
 * Revision 1.1.1.1  1998/03/07 02:25:45  wsanchez
 * Import of OSF Mach kernel (~mburg)
 *
 * Revision 1.1.4.1  1995/06/13  18:20:29  sjs
 * 	Merged from flipc_shared.
 * 	[95/06/07            sjs]
 *
 * Revision 1.1.2.3  1995/03/09  19:42:30  rwd
 * 	Move yield function out of macro and prototype.
 * 	[1995/03/09  19:36:25  rwd]
 * 
 * Revision 1.1.2.2  1995/02/21  17:23:11  randys
 * 	Re-indented code to four space indentation
 * 	[1995/02/21  16:25:39  randys]
 * 
 * Revision 1.1.2.1  1994/12/20  19:02:06  randys
 * 	Moved definition of flipc_simple_lock to flipc_cb.h
 * 	[1994/12/20  17:34:44  randys]
 * 
 * 	Separated the lock macros out into machine dependent and independent files;
 * 	this is the machine independent file.
 * 	[1994/12/20  16:43:38  randys]
 * 
 * $EndLog$
 */

/*
 * mach/flipc_locks.h
 *
 * The machine independent part of the flipc_simple_locks definitions.
 * Most of the locks definitions is in flipc_dep.h, but what isn't
 * dependent on the platform being used is here.
 */

/*
 * Note that the locks defined in this file and in flipc_dep.h are only
 * for use by user level code.  The reason why this file is visible to
 * the kernel is that the kernel section of flipc needs to initialize
 * these locks.
 */

#ifndef _MACH_FLIPC_LOCKS_H_
#define _MACH_FLIPC_LOCKS_H_

/* Get the simple lock type.  */
#include <mach/flipc_cb.h>

/*
 * Lock function prototypes.  This needs to be before any lock definitions
 * that happen to be macros.
 */

/* Initializes lock.  Always a macro (so that kernel code can use it without
   library assistance).  */
void flipc_simple_lock_init(flipc_simple_lock *lock);

/* Returns 1 if lock gained, 0 otherwise.  */
int flipc_simple_lock_try(flipc_simple_lock *lock);

/* Returns 1 if lock is locked, 0 otherwise.  */
int flipc_simple_lock_locked(flipc_simple_lock *lock);

/* Releases the lock.  */
void flipc_simple_lock_release(flipc_simple_lock *lock);

/* Take the lock.  */
void flipc_simple_lock_acquire(flipc_simple_lock *lock);

/* Take two locks.  Does not hold one while spinning on the
   other.  */
void flipc_simple_lock_acquire_2(flipc_simple_lock *lock1,
			   flipc_simple_lock *lock2);

/* Get the machine dependent stuff.  The things that need to be
 * defined in a machine dependent fashion are:
 *
 *   flipc_simple_lock_init	(must be a macro)
 *   flipc_simple_lock_try
 *   flipc_simple_lock_locked
 *   flipc_simple_lock_release
 *
 * These last three don't necessarily have to be macros, but if they
 * aren't definitions must be included in the machine dependent
 * part of the user level library code.
 */
#include <mach/machine/flipc_dep.h>

/*
 * Set at flipc initialization time to thread_yield argument to
 * FLIPC_domain_init
 */

extern void (*flipc_simple_lock_yield_fn)(void);

/*
 * Machine independent definitions; defined in terms of above routines.
 */

/* Take the lock.  Assumes an external define saying how long to
   spin, and an external function to call when we've spun too long.  */
#define flipc_simple_lock_acquire(lock)		\
do {						\
  int __spin_count = 0;				\
						\
  while (flipc_simple_lock_locked(lock)		\
	 || !flipc_simple_lock_try(lock))	\
    if (++__spin_count > LOCK_SPIN_LIMIT) {	\
      (*flipc_simple_lock_yield_fn)();		\
      __spin_count = 0;				\
    }						\
} while (0)

/* Take two locks.  Hold neither while spinning on the other.  */
#define flipc_simple_lock_acquire_2(lock1, lock2)	\
do {							\
  int __spin_count = 0;					\
							\
  while (1) {						\
    while (flipc_simple_lock_locked(lock1)		\
	   || !flipc_simple_lock_try(lock1))		\
      if (++__spin_count > LOCK_SPIN_LIMIT) {		\
	(*flipc_simple_lock_yield_fn)();		\
	__spin_count = 0;				\
      }							\
							\
    if (flipc_simple_lock_try(lock2))			\
      break;						\
    flipc_simple_lock_release(lock1);			\
							\
    while (flipc_simple_lock_locked(lock2)		\
	   || !flipc_simple_lock_try(lock2))		\
      if (++__spin_count > LOCK_SPIN_LIMIT) {		\
	(*flipc_simple_lock_yield_fn)();		\
	__spin_count = 0;				\
      }							\
							\
    if (flipc_simple_lock_try(lock1))			\
      break;						\
    flipc_simple_lock_release(lock2);			\
  }							\
} while (0)

#endif	/* _MACH_FLIPC_LOCKS_H_ */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* @OSF_COPYRIGHT@
	30	*
	31	*/
	32	/*
	33	* HISTORY
	34	*
	35	* Revision 1.1.1.1 1998/09/22 21:05:30 wsanchez
	36	* Import of Mac OS X kernel (~semeria)
	37	*
	38	* Revision 1.1.1.1 1998/03/07 02:25:45 wsanchez
	39	* Import of OSF Mach kernel (~mburg)
	40	*
	41	* Revision 1.1.4.1 1995/06/13 18:20:29 sjs
	42	* Merged from flipc_shared.
	43	* [95/06/07 sjs]
	44	*
	45	* Revision 1.1.2.3 1995/03/09 19:42:30 rwd
	46	* Move yield function out of macro and prototype.
	47	* [1995/03/09 19:36:25 rwd]
	48	*
	49	* Revision 1.1.2.2 1995/02/21 17:23:11 randys
	50	* Re-indented code to four space indentation
	51	* [1995/02/21 16:25:39 randys]
	52	*
	53	* Revision 1.1.2.1 1994/12/20 19:02:06 randys
	54	* Moved definition of flipc_simple_lock to flipc_cb.h
	55	* [1994/12/20 17:34:44 randys]
	56	*
	57	* Separated the lock macros out into machine dependent and independent files;
	58	* this is the machine independent file.
	59	* [1994/12/20 16:43:38 randys]
	60	*
	61	* $EndLog$
	62	*/
	63
	64	/*
	65	* mach/flipc_locks.h
	66	*
	67	* The machine independent part of the flipc_simple_locks definitions.
	68	* Most of the locks definitions is in flipc_dep.h, but what isn't
	69	* dependent on the platform being used is here.
	70	*/
	71
	72	/*
	73	* Note that the locks defined in this file and in flipc_dep.h are only
	74	* for use by user level code. The reason why this file is visible to
	75	* the kernel is that the kernel section of flipc needs to initialize
	76	* these locks.
	77	*/
	78
	79	#ifndef _MACH_FLIPC_LOCKS_H_
	80	#define _MACH_FLIPC_LOCKS_H_
	81
	82	/* Get the simple lock type. */
	83	#include <mach/flipc_cb.h>
	84
	85	/*
	86	* Lock function prototypes. This needs to be before any lock definitions
	87	* that happen to be macros.
	88	*/
	89
	90	/* Initializes lock. Always a macro (so that kernel code can use it without
91	library assistance). */
92	void flipc_simple_lock_init(flipc_simple_lock *lock);
93
94	/* Returns 1 if lock gained, 0 otherwise. */
95	int flipc_simple_lock_try(flipc_simple_lock *lock);
96
97	/* Returns 1 if lock is locked, 0 otherwise. */
98	int flipc_simple_lock_locked(flipc_simple_lock *lock);
99
100	/* Releases the lock. */
101	void flipc_simple_lock_release(flipc_simple_lock *lock);
102
103	/* Take the lock. */
104	void flipc_simple_lock_acquire(flipc_simple_lock *lock);
105
106	/* Take two locks. Does not hold one while spinning on the
107	other. */
108	void flipc_simple_lock_acquire_2(flipc_simple_lock *lock1,
109	flipc_simple_lock *lock2);
110
111	/* Get the machine dependent stuff. The things that need to be
112	* defined in a machine dependent fashion are:
113	*
114	* flipc_simple_lock_init (must be a macro)
115	* flipc_simple_lock_try
116	* flipc_simple_lock_locked
117	* flipc_simple_lock_release
118	*
119	* These last three don't necessarily have to be macros, but if they
120	* aren't definitions must be included in the machine dependent
121	* part of the user level library code.
122	*/
123	#include <mach/machine/flipc_dep.h>
124
125	/*
126	* Set at flipc initialization time to thread_yield argument to
127	* FLIPC_domain_init
128	*/
129
130	extern void (*flipc_simple_lock_yield_fn)(void);
131
132	/*
133	* Machine independent definitions; defined in terms of above routines.
134	*/
135
136	/* Take the lock. Assumes an external define saying how long to
137	spin, and an external function to call when we've spun too long. */
138	#define flipc_simple_lock_acquire(lock) \
139	do { \
140	int __spin_count = 0; \
141	\
142	while (flipc_simple_lock_locked(lock) \
143	\|\| !flipc_simple_lock_try(lock)) \
144	if (++__spin_count > LOCK_SPIN_LIMIT) { \
145	(*flipc_simple_lock_yield_fn)(); \
146	__spin_count = 0; \
147	} \
148	} while (0)
149
150	/* Take two locks. Hold neither while spinning on the other. */
151	#define flipc_simple_lock_acquire_2(lock1, lock2) \
152	do { \
153	int __spin_count = 0; \
154	\
155	while (1) { \
156	while (flipc_simple_lock_locked(lock1) \
157	\|\| !flipc_simple_lock_try(lock1)) \
158	if (++__spin_count > LOCK_SPIN_LIMIT) { \
159	(*flipc_simple_lock_yield_fn)(); \
160	__spin_count = 0; \
161	} \
162	\
163	if (flipc_simple_lock_try(lock2)) \
164	break; \
165	flipc_simple_lock_release(lock1); \
166	\
167	while (flipc_simple_lock_locked(lock2) \
168	\|\| !flipc_simple_lock_try(lock2)) \
169	if (++__spin_count > LOCK_SPIN_LIMIT) { \
170	(*flipc_simple_lock_yield_fn)(); \
171	__spin_count = 0; \
172	} \
173	\
174	if (flipc_simple_lock_try(lock1)) \
175	break; \
176	flipc_simple_lock_release(lock2); \
177	} \
178	} while (0)
179
180	#endif /* _MACH_FLIPC_LOCKS_H_ */