| | 1 | /* |
| | 2 | * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. |
| | 3 | * |
| | 4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
| | 5 | * |
| | 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. |
| | 14 | * |
| | 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 |
| | 20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| | 21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
| | 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. |
| | 25 | * |
| | 26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
| | 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_ */ |
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