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/*
* 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_ */