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/* IOSyncer.cpp created by wgulland on 2000-02-02 */
29
30#include <IOKit/IOLib.h>
31#include <IOKit/IOSyncer.h>
32
33OSDefineMetaClassAndStructors(IOSyncer, OSObject)
34
35IOSyncer * IOSyncer::create(bool twoRetains)
36{
37 IOSyncer * me = new IOSyncer;
38
39 if (me && !me->init(twoRetains)) {
40 me->release();
41 return 0;
42 }
43
44 return me;
45}
46
47bool IOSyncer::init(bool twoRetains)
48{
49 if (!OSObject::init())
50 return false;
51
52 if (!(guardLock = IOSimpleLockAlloc()) )
53 return false;
54
55 IOSimpleLockInit(guardLock);
56
57 if(twoRetains)
58 retain();
59
60 fResult = kIOReturnSuccess;
61
62 reinit();
63
64 return true;
65}
66
67void IOSyncer::reinit()
68{
69 IOInterruptState is = IOSimpleLockLockDisableInterrupt(guardLock);
70 threadMustStop = true;
71 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
72}
73
74void IOSyncer::free()
75{
76 // just in case a thread is blocked here:
77 privateSignal();
78
79 if (guardLock != NULL)
80 IOSimpleLockFree(guardLock);
81
82 OSObject::free();
83}
84
85IOReturn IOSyncer::wait(bool autoRelease)
86{
87 IOInterruptState is = IOSimpleLockLockDisableInterrupt(guardLock);
88
89 if (threadMustStop) {
90 assert_wait((void *) &threadMustStop, false);
91 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
92 thread_block(THREAD_CONTINUE_NULL);
93 }
94 else
95 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
96
97 IOReturn result = fResult; // Pick up before auto deleting!
98
99 if(autoRelease)
100 release();
101
102 return result;
103}
104
105void IOSyncer::signal(IOReturn res, bool autoRelease)
106{
107 fResult = res;
108 privateSignal();
109 if(autoRelease)
110 release();
111}
112
113void IOSyncer::privateSignal()
114{
115 if (threadMustStop) {
116 IOInterruptState is = IOSimpleLockLockDisableInterrupt(guardLock);
117 threadMustStop = false;
118 thread_wakeup_one((void *) &threadMustStop);
119 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
120 }
121}
122