1 /*
2 * Copyright (C) 2011 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 #include "CallbackProtector.h"
18 #include "sllog.h"
19
20 #include <media/stagefright/foundation/ADebug.h>
21
22 //--------------------------------------------------------------------------------------------------
23 namespace android {
24
25
CallbackProtector()26 CallbackProtector::CallbackProtector() : RefBase(),
27 mSafeToEnterCb(true),
28 mCbCount(0)
29 #ifdef USE_DEBUG
30 , mCallbackThread((pthread_t) NULL),
31 mCallbackTid(0),
32 mRequesterThread((pthread_t) NULL),
33 mRequesterTid(0)
34 #endif
35 {
36 }
37
38
~CallbackProtector()39 CallbackProtector::~CallbackProtector() {
40 Mutex::Autolock _l(mLock);
41 if (mCbCount) {
42 SL_LOGE("Callback protector detected an active callback after destroy");
43 }
44
45 }
46
47
48 // static
enterCbIfOk(const sp<CallbackProtector> & protector)49 bool CallbackProtector::enterCbIfOk(const sp<CallbackProtector> &protector) {
50 if (protector != 0) {
51 return protector->enterCb();
52 } else {
53 SL_LOGE("Callback protector is missing");
54 return false;
55 }
56 }
57
58
enterCb()59 bool CallbackProtector::enterCb() {
60 Mutex::Autolock _l(mLock);
61 if (mSafeToEnterCb) {
62 mCbCount++;
63 #ifdef USE_DEBUG
64 if (mCbCount > 1) {
65 SL_LOGV("Callback protector allowed multiple or nested callback entry: %u", mCbCount);
66 } else {
67 mCallbackThread = pthread_self();
68 mCallbackTid = gettid();
69 }
70 #endif
71 } else {
72 #ifdef USE_DEBUG
73 SL_LOGV("Callback protector denied callback entry by thread %p tid %d during destroy"
74 " requested by thread %p tid %d",
75 (void *) pthread_self(), gettid(),
76 (void *) mRequesterThread, mRequesterTid);
77 #else
78 SL_LOGV("Callback protector denied callback entry during destroy");
79 #endif
80 }
81 return mSafeToEnterCb;
82 }
83
84
exitCb()85 void CallbackProtector::exitCb() {
86 Mutex::Autolock _l(mLock);
87
88 CHECK(mCbCount > 0);
89 mCbCount--;
90
91 if (mCbCount == 0) {
92 if (!mSafeToEnterCb) {
93 #ifdef USE_DEBUG
94 SL_LOGV("Callback protector detected return from callback by thread %p tid %d during"
95 " destroy requested by thread %p tid %d",
96 (void *) mCallbackThread, mCallbackTid,
97 (void *) mRequesterThread, mRequesterTid);
98 #else
99 SL_LOGV("Callback protector detected return from callback during destroy");
100 #endif
101 mCbExitedCondition.broadcast();
102 }
103 #ifdef USE_DEBUG
104 mCallbackThread = (pthread_t) NULL;
105 mCallbackTid = 0;
106 #endif
107 }
108 }
109
110
requestCbExitAndWait()111 void CallbackProtector::requestCbExitAndWait() {
112 Mutex::Autolock _l(mLock);
113 mSafeToEnterCb = false;
114 #ifdef USE_DEBUG
115 mRequesterThread = pthread_self();
116 mRequesterTid = gettid();
117 #endif
118 while (mCbCount) {
119 #ifdef USE_DEBUG
120 SL_LOGV("Callback protector detected in-progress callback by thread %p tid %d during"
121 " blocking destroy requested by thread %p tid %d",
122 (void *) mCallbackThread, mCallbackTid,
123 (void *) pthread_self(), gettid());
124 #else
125 SL_LOGV("Callback protector detected in-progress callback during blocking destroy");
126 #endif
127 mCbExitedCondition.wait(mLock);
128 }
129 }
130
131
requestCbExit()132 void CallbackProtector::requestCbExit() {
133 Mutex::Autolock _l(mLock);
134 mSafeToEnterCb = false;
135 #ifdef USE_DEBUG
136 mRequesterThread = pthread_self();
137 mRequesterTid = gettid();
138 #endif
139 if (mCbCount) {
140 #ifdef USE_DEBUG
141 SL_LOGV("Callback protector detected in-progress callback by thread %p tid %d during"
142 " non-blocking destroy requested by thread %p tid %d",
143 (void *) mCallbackThread, mCallbackTid,
144 (void *) pthread_self(), gettid());
145 #else
146 SL_LOGV("Callback protector detected in-progress callback during non-blocking destroy");
147 #endif
148 }
149 }
150
151 } // namespace android
152