IMediaDeathNotifier.cpp revision dd172fce75b2a1c3cb3a5d3b3bbb5020b1ae8675 
1/*
2** Copyright 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//#define LOG_NDEBUG 0
18#define LOG_TAG "IMediaDeathNotifier"
19#include <utils/Log.h>
20
21#include <binder/IServiceManager.h>
22#include <binder/IPCThreadState.h>
23#include <media/IMediaDeathNotifier.h>
24
25namespace android {
26
27// client singleton for binder interface to services
28Mutex IMediaDeathNotifier::sServiceLock;
29sp<IMediaPlayerService> IMediaDeathNotifier::sMediaPlayerService;
30sp<IMediaDeathNotifier::DeathNotifier> IMediaDeathNotifier::sDeathNotifier;
31SortedVector< wp<IMediaDeathNotifier> > IMediaDeathNotifier::sObitRecipients;
32
33// establish binder interface to MediaPlayerService
34/*static*/const sp<IMediaPlayerService>&
35IMediaDeathNotifier::getMediaPlayerService()
36{
37    LOGV("getMediaPlayerService");
38    Mutex::Autolock _l(sServiceLock);
39    if (sMediaPlayerService.get() == 0) {
40        sp<IServiceManager> sm = defaultServiceManager();
41        sp<IBinder> binder;
42        do {
43            binder = sm->getService(String16("media.player"));
44            if (binder != 0) {
45                break;
46             }
47             LOGW("Media player service not published, waiting...");
48             usleep(500000); // 0.5 s
49        } while(true);
50
51        if (sDeathNotifier == NULL) {
52        sDeathNotifier = new DeathNotifier();
53    }
54    binder->linkToDeath(sDeathNotifier);
55    sMediaPlayerService = interface_cast<IMediaPlayerService>(binder);
56    }
57    LOGE_IF(sMediaPlayerService == 0, "no media player service!?");
58    return sMediaPlayerService;
59}
60
61/*static*/ void
62IMediaDeathNotifier::addObitRecipient(const wp<IMediaDeathNotifier>& recipient)
63{
64    LOGV("addObitRecipient");
65    Mutex::Autolock _l(sServiceLock);
66    sObitRecipients.add(recipient);
67}
68
69/*static*/ void
70IMediaDeathNotifier::removeObitRecipient(const wp<IMediaDeathNotifier>& recipient)
71{
72    LOGV("removeObitRecipient");
73    Mutex::Autolock _l(sServiceLock);
74    sObitRecipients.remove(recipient);
75}
76
77void
78IMediaDeathNotifier::DeathNotifier::binderDied(const wp<IBinder>& who) {
79    LOGW("media server died");
80
81    // Need to do this with the lock held
82    SortedVector< wp<IMediaDeathNotifier> > list;
83    {
84        Mutex::Autolock _l(sServiceLock);
85        sMediaPlayerService.clear();
86        list = sObitRecipients;
87    }
88
89    // Notify application when media server dies.
90    // Don't hold the static lock during callback in case app
91    // makes a call that needs the lock.
92    size_t count = list.size();
93    for (size_t iter = 0; iter < count; ++iter) {
94        sp<IMediaDeathNotifier> notifier = list[iter].promote();
95        if (notifier != 0) {
96            notifier->died();
97        }
98    }
99}
100
101IMediaDeathNotifier::DeathNotifier::~DeathNotifier()
102{
103    LOGV("DeathNotifier::~DeathNotifier");
104    Mutex::Autolock _l(sServiceLock);
105    sObitRecipients.clear();
106    if (sMediaPlayerService != 0) {
107        sMediaPlayerService->asBinder()->unlinkToDeath(this);
108    }
109}
110
111}; // namespace android
112