1/*
2 * Copyright (C) 2009 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#define LOG_TAG "MediaBufferGroup"
18#include <utils/Log.h>
19
20#include <media/stagefright/foundation/ADebug.h>
21#include <media/stagefright/MediaBuffer.h>
22#include <media/stagefright/MediaBufferGroup.h>
23
24namespace android {
25
26MediaBufferGroup::MediaBufferGroup()
27    : mFirstBuffer(NULL),
28      mLastBuffer(NULL) {
29}
30
31MediaBufferGroup::~MediaBufferGroup() {
32    MediaBuffer *next;
33    for (MediaBuffer *buffer = mFirstBuffer; buffer != NULL;
34         buffer = next) {
35        next = buffer->nextBuffer();
36
37        CHECK_EQ(buffer->refcount(), 0);
38
39        buffer->setObserver(NULL);
40        buffer->release();
41    }
42}
43
44void MediaBufferGroup::add_buffer(MediaBuffer *buffer) {
45    Mutex::Autolock autoLock(mLock);
46
47    buffer->setObserver(this);
48
49    if (mLastBuffer) {
50        mLastBuffer->setNextBuffer(buffer);
51    } else {
52        mFirstBuffer = buffer;
53    }
54
55    mLastBuffer = buffer;
56}
57
58status_t MediaBufferGroup::acquire_buffer(MediaBuffer **out) {
59    Mutex::Autolock autoLock(mLock);
60
61    for (;;) {
62        for (MediaBuffer *buffer = mFirstBuffer;
63             buffer != NULL; buffer = buffer->nextBuffer()) {
64            if (buffer->refcount() == 0) {
65                buffer->add_ref();
66                buffer->reset();
67
68                *out = buffer;
69                goto exit;
70            }
71        }
72
73        // All buffers are in use. Block until one of them is returned to us.
74        mCondition.wait(mLock);
75    }
76
77exit:
78    return OK;
79}
80
81void MediaBufferGroup::signalBufferReturned(MediaBuffer *) {
82    Mutex::Autolock autoLock(mLock);
83    mCondition.signal();
84}
85
86}  // namespace android
87