1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 /* ThreadSync implementation */
18
19 #include "sles_allinclusive.h"
20
21
IThreadSync_EnterCriticalSection(SLThreadSyncItf self)22 static SLresult IThreadSync_EnterCriticalSection(SLThreadSyncItf self)
23 {
24 SL_ENTER_INTERFACE
25
26 IThreadSync *thiz = (IThreadSync *) self;
27 interface_lock_exclusive(thiz);
28 for (;;) {
29 if (thiz->mInCriticalSection) {
30 if (!pthread_equal(thiz->mOwner, pthread_self())) {
31 ++thiz->mWaiting;
32 interface_cond_wait(thiz);
33 continue;
34 }
35 // nested locks are not allowed
36 result = SL_RESULT_PRECONDITIONS_VIOLATED;
37 break;
38 }
39 thiz->mInCriticalSection = SL_BOOLEAN_TRUE;
40 thiz->mOwner = pthread_self();
41 result = SL_RESULT_SUCCESS;
42 break;
43 }
44 interface_unlock_exclusive(thiz);
45
46 SL_LEAVE_INTERFACE
47 }
48
49
IThreadSync_ExitCriticalSection(SLThreadSyncItf self)50 static SLresult IThreadSync_ExitCriticalSection(SLThreadSyncItf self)
51 {
52 SL_ENTER_INTERFACE
53
54 IThreadSync *thiz = (IThreadSync *) self;
55 interface_lock_exclusive(thiz);
56 if (!thiz->mInCriticalSection || !pthread_equal(thiz->mOwner, pthread_self())) {
57 result = SL_RESULT_PRECONDITIONS_VIOLATED;
58 } else {
59 thiz->mInCriticalSection = SL_BOOLEAN_FALSE;
60 memset(&thiz->mOwner, 0, sizeof(pthread_t));
61 if (thiz->mWaiting) {
62 --thiz->mWaiting;
63 interface_cond_signal(thiz);
64 }
65 result = SL_RESULT_SUCCESS;
66 }
67 interface_unlock_exclusive(thiz);
68
69 SL_LEAVE_INTERFACE
70 }
71
72
73 static const struct SLThreadSyncItf_ IThreadSync_Itf = {
74 IThreadSync_EnterCriticalSection,
75 IThreadSync_ExitCriticalSection
76 };
77
IThreadSync_init(void * self)78 void IThreadSync_init(void *self)
79 {
80 IThreadSync *thiz = (IThreadSync *) self;
81 thiz->mItf = &IThreadSync_Itf;
82 thiz->mInCriticalSection = SL_BOOLEAN_FALSE;
83 thiz->mWaiting = 0;
84 memset(&thiz->mOwner, 0, sizeof(pthread_t));
85 }
86
IThreadSync_deinit(void * self)87 void IThreadSync_deinit(void *self)
88 {
89 IThreadSync *thiz = (IThreadSync *) self;
90 if (thiz->mInCriticalSection) {
91 SL_LOGW("ThreadSync::EnterCriticalSection was active at Engine::Destroy");
92 }
93 }
94