iokit/IOKit/IOSharedLock.h

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