iokit/IOKit/IOSharedLock.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
  32  *
  33  * HISTORY
  34  *
  35  */
  36
  37 /*
  38  * Multiprocessor locks used within the shared memory area between the
  39  * kernel and event system.  These must work in both user and kernel mode.
  40  *
  41  * These routines are public, for the purpose of writing frame buffer device
  42  * drivers which handle their own cursors.  Certain architectures define a
  43  * generic display class which handles cursor drawing and is subclassed by
  44  * driver writers.  These drivers need not be concerned with the following
  45  * types and definitions.
  46  *
  47  * The ev_lock(), ev_unlock(), and ev_try_lock() functions are available only
  48  * to drivers built in or dynamically loaded into the kernel, and to DPS
  49  * drivers built in or dynamically loaded into the Window Server.  They do not
  50  * exist in any shared library.
  51  *
  52  * --> They're now in IOKit user lib.
  53  */
  54
  55 #ifndef _IOKIT_IOSHAREDLOCK_H
  56 #define _IOKIT_IOSHAREDLOCK_H
  57
  58 #ifdef __cplusplus
  59 extern "C" {
  60 #endif
  61
  62 // should be 32 bytes on PPC
  63 typedef volatile int            IOSharedLockData;
  64 typedef IOSharedLockData    *   IOSharedLock;
  65
  66 #define IOSpinLockInit(l)       (*(l) = (IOSharedLockData)0)
  67
  68 #ifndef KERNEL
  69 extern void IOSpinLock(IOSharedLock l);
  70 #endif
  71
  72 extern void IOSpinUnlock(IOSharedLock l);
  73 extern boolean_t IOTrySpinLock(IOSharedLock l);
  74
  75 /* exact same stuff & implementation */
  76
  77 typedef IOSharedLockData        ev_lock_data_t;
  78 typedef ev_lock_data_t      *   ev_lock_t;
  79
  80 #define ev_init_lock(l)         (*(l) = (ev_lock_data_t)0)
  81 // needs isync?
  82 //#define ev_is_locked(l)       (*(l) != (ev_lock_data_t)0)
  83
  84 #ifndef KERNEL
  85 extern void ev_lock(ev_lock_t l);               // Spin lock!
  86 #endif
  87
  88 extern void ev_unlock(ev_lock_t l);
  89 extern boolean_t ev_try_lock(ev_lock_t l);
  90
  91 #ifdef __cplusplus
  92 }
  93 #endif
  94 #endif /* ! _IOKIT_IOSHAREDLOCK_H */