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
OSDefineMetaClassAndStructors(IOSyncer,OSObject)33 OSDefineMetaClassAndStructors(IOSyncer, OSObject)
34
35 IOSyncer * IOSyncer::create(bool twoRetains)
36 {
37 IOSyncer * me = new IOSyncer;
38
39 if (me && !me->init(twoRetains)) {
40 me->release();
41 return NULL;
42 }
43
44 return me;
45 }
46
47 bool
init(bool twoRetains)48 IOSyncer::init(bool twoRetains)
49 {
50 if (!OSObject::init()) {
51 return false;
52 }
53
54 if (!(guardLock = IOSimpleLockAlloc())) {
55 return false;
56 }
57
58 IOSimpleLockInit(guardLock);
59
60 if (twoRetains) {
61 retain();
62 }
63
64 fResult = kIOReturnSuccess;
65
66 reinit();
67
68 return true;
69 }
70
71 void
reinit()72 IOSyncer::reinit()
73 {
74 IOInterruptState is = IOSimpleLockLockDisableInterrupt(guardLock);
75 threadMustStop = true;
76 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
77 }
78
79 void
free()80 IOSyncer::free()
81 {
82 // just in case a thread is blocked here:
83 privateSignal();
84
85 if (guardLock != NULL) {
86 IOSimpleLockFree(guardLock);
87 }
88
89 OSObject::free();
90 }
91
92 IOReturn
wait(bool autoRelease)93 IOSyncer::wait(bool autoRelease)
94 {
95 IOInterruptState is = IOSimpleLockLockDisableInterrupt(guardLock);
96
97 if (threadMustStop) {
98 assert_wait((void *) &threadMustStop, false);
99 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
100 thread_block(THREAD_CONTINUE_NULL);
101 } else {
102 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
103 }
104
105 IOReturn result = fResult; // Pick up before auto deleting!
106
107 if (autoRelease) {
108 release();
109 }
110
111 return result;
112 }
113
114 void
signal(IOReturn res,bool autoRelease)115 IOSyncer::signal(IOReturn res, bool autoRelease)
116 {
117 fResult = res;
118 privateSignal();
119 if (autoRelease) {
120 release();
121 }
122 }
123
124 void
privateSignal()125 IOSyncer::privateSignal()
126 {
127 if (threadMustStop) {
128 IOInterruptState is = IOSimpleLockLockDisableInterrupt(guardLock);
129 threadMustStop = false;
130 thread_wakeup_one((void *) &threadMustStop);
131 IOSimpleLockUnlockEnableInterrupt(guardLock, is);
132 }
133 }
134