CallbackProtector.cpp revision 6cce136651f6fd2c7aecd45bc553270152d75462 
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
19#include <media/stagefright/foundation/ADebug.h>
20
21//--------------------------------------------------------------------------------------------------
22namespace android {
23
24
25CallbackProtector::CallbackProtector() : RefBase(),
26        mSafeToEnterCb(true),
27        mCbCount(0) {
28}
29
30
31CallbackProtector::~CallbackProtector() {
32
33}
34
35
36bool CallbackProtector::enterCbIfOk(const sp<CallbackProtector> &protector) {
37    if (protector != 0) {
38        return protector->enterCb();
39    } else {
40        return false;
41    }
42}
43
44
45bool CallbackProtector::enterCb() {
46    Mutex::Autolock _l(mLock);
47    if (mSafeToEnterCb) {
48        mCbCount++;
49    }
50    return mSafeToEnterCb;
51}
52
53
54void CallbackProtector::exitCb() {
55    Mutex::Autolock _l(mLock);
56
57    CHECK(mCbCount > 0);
58    mCbCount--;
59
60    if (mCbCount == 0) {
61        mCbExitedCondition.broadcast();
62    }
63}
64
65
66void CallbackProtector::requestCbExitAndWait() {
67    Mutex::Autolock _l(mLock);
68    mSafeToEnterCb = false;
69    while (mCbCount) {
70        mCbExitedCondition.wait(mLock);
71    }
72}
73
74
75} // namespace android
76