iokit/IOKit/IOSharedLock.h

   1 /*
   2  * Copyright (c) 1998-2000 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  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
  30  *
  31  * HISTORY
  32  *
  33  */
  34
  35 /*
  36  * Multiprocessor locks used within the shared memory area between the
  37  * kernel and event system.  These must work in both user and kernel mode.
  38  *
  39  * These routines are public, for the purpose of writing frame buffer device
  40  * drivers which handle their own cursors.  Certain architectures define a
  41  * generic display class which handles cursor drawing and is subclassed by
  42  * driver writers.  These drivers need not be concerned with the following
  43  * types and definitions.
  44  *
  45  * The ev_lock(), ev_unlock(), and ev_try_lock() functions are available only
  46  * to drivers built in or dynamically loaded into the kernel, and to DPS
  47  * drivers built in or dynamically loaded into the Window Server.  They do not
  48  * exist in any shared library.
  49  *
  50  * --> They're now in IOKit user lib.
  51  */
  52
  53 #ifndef _IOKIT_IOSHAREDLOCK_H
  54 #define _IOKIT_IOSHAREDLOCK_H
  55
  56 #ifdef __cplusplus
  57 extern "C" {
  58 #endif
  59
  60 // should be 32 bytes on PPC
  61 typedef volatile int            IOSharedLockData;
  62 typedef IOSharedLockData    *   IOSharedLock;
  63
  64 #define IOSpinLockInit(l)       (*(l) = (IOSharedLockData)0)
  65
  66 #ifndef KERNEL
  67 extern void IOSpinLock(IOSharedLock l);
  68 #endif
  69
  70 extern void IOSpinUnlock(IOSharedLock l);
  71 extern boolean_t IOTrySpinLock(IOSharedLock l);
  72
  73 /* exact same stuff & implementation */
  74
  75 typedef IOSharedLockData        ev_lock_data_t;
  76 typedef ev_lock_data_t      *   ev_lock_t;
  77
  78 #define ev_init_lock(l)         (*(l) = (ev_lock_data_t)0)
  79 // needs isync?
  80 //#define ev_is_locked(l)       (*(l) != (ev_lock_data_t)0)
  81
  82 #ifndef KERNEL
  83 extern void ev_lock(ev_lock_t l);               // Spin lock!
  84 #endif
  85
  86 extern void ev_unlock(ev_lock_t l);
  87 extern boolean_t ev_try_lock(ev_lock_t l);
  88
  89 #ifdef __cplusplus
  90 }
  91 #endif
  92 #endif /* ! _IOKIT_IOSHAREDLOCK_H */