Return to simple_lock.h CVS log

Up to [Apple Darwin 0.x] / kernel / mach / i386

Annotation of kernel/mach/i386/simple_lock.h, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
        !             3:  *
        !             4:  * @APPLE_LICENSE_HEADER_START@
        !             5:  * 
        !             6:  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
        !             7:  * Reserved.  This file contains Original Code and/or Modifications of
        !             8:  * Original Code as defined in and that are subject to the Apple Public
        !             9:  * Source License Version 1.1 (the "License").  You may not use this file
        !            10:  * except in compliance with the License.  Please obtain a copy of the
        !            11:  * License at http://www.apple.com/publicsource and read it before using
        !            12:  * this file.
        !            13:  * 
        !            14:  * The Original Code and all software distributed under the License are
        !            15:  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
        !            16:  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
        !            17:  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
        !            18:  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
        !            19:  * License for the specific language governing rights and limitations
        !            20:  * under the License.
        !            21:  * 
        !            22:  * @APPLE_LICENSE_HEADER_END@
        !            23:  */
        !            24: 
        !            25: /*
        !            26:  * Copyright (c) 1992 NeXT Computer, Inc.
        !            27:  *
        !            28:  * Simple spin locks.
        !            29:  *
        !            30:  * HISTORY
        !            31:  *
        !            32:  * 19 November 1992 ? at NeXT
        !            33:  *     Created.
        !            34:  */
        !            35:  
        !            36: #import <mach/boolean.h>
        !            37: 
        !            38: #ifndef        _MACH_I386_SIMPLE_LOCK_H_
        !            39: #define _MACH_I386_SIMPLE_LOCK_H_
        !            40: 
        !            41: #define _MACHINE_SIMPLE_LOCK_DATA_
        !            42: 
        !            43: struct slock {
        !            44:     boolean_t          locked;
        !            45: };
        !            46: 
        !            47: typedef struct slock           simple_lock_data_t;
        !            48: typedef simple_lock_data_t     *simple_lock_t;
        !            49: 
        !            50: static __inline__
        !            51: void
        !            52: simple_lock_init(
        !            53:     simple_lock_t      slock
        !            54: )
        !            55: {
        !            56:     slock->locked = FALSE;
        !            57: }
        !            58: 
        !            59: static __inline__
        !            60: boolean_t
        !            61: simple_lock_try(
        !            62:     simple_lock_t      slock
        !            63: )
        !            64: {
        !            65:     boolean_t          result;
        !            66:     
        !            67:     asm volatile(
        !            68:        "xchgl %1,%0; xorl %3,%0"
        !            69:            : "=r" (result), "=m" (slock->locked)
        !            70:            : "0" (TRUE), "i" (TRUE));
        !            71:            
        !            72:     return (result);
        !            73: }
        !            74: 
        !            75: static __inline__
        !            76: void
        !            77: simple_lock(
        !            78:     simple_lock_t      slock
        !            79: )
        !            80: {    
        !            81:     do
        !            82:        {
        !            83:            while (slock->locked)
        !            84:                continue;
        !            85:        }
        !            86:     while (!simple_lock_try(slock));
        !            87: }
        !            88: 
        !            89: static __inline__
        !            90: void
        !            91: simple_unlock(
        !            92:     simple_lock_t      slock
        !            93: )
        !            94: {
        !            95:     boolean_t          result;
        !            96:     
        !            97:     asm volatile(
        !            98:        "xchgl %1,%0"
        !            99:            : "=r" (result), "=m" (slock->locked)
        !           100:            : "0" (FALSE));
        !           101: }
        !           102: 
        !           103: #endif /* _MACH_I386_SIMPLE_LOCK_H_ */

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.