1 /*
2 * Copyright (C) 2013 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 "MediaLog"
18 //#define LOG_NDEBUG 0
19
20 #include <sys/mman.h>
21 #include <utils/Log.h>
22 #include <binder/PermissionCache.h>
23 #include <media/nbaio/NBLog.h>
24 #include <private/android_filesystem_config.h>
25 #include "MediaLogService.h"
26
27 namespace android {
28
29 static const char kDeadlockedString[] = "MediaLogService may be deadlocked\n";
30
registerWriter(const sp<IMemory> & shared,size_t size,const char * name)31 void MediaLogService::registerWriter(const sp<IMemory>& shared, size_t size, const char *name)
32 {
33 if (IPCThreadState::self()->getCallingUid() != AID_AUDIOSERVER || shared == 0 ||
34 size < kMinSize || size > kMaxSize || name == NULL ||
35 shared->size() < NBLog::Timeline::sharedSize(size)) {
36 return;
37 }
38 sp<NBLog::Reader> reader(new NBLog::Reader(size, shared));
39 NamedReader namedReader(reader, name);
40 Mutex::Autolock _l(mLock);
41 mNamedReaders.add(namedReader);
42 }
43
unregisterWriter(const sp<IMemory> & shared)44 void MediaLogService::unregisterWriter(const sp<IMemory>& shared)
45 {
46 if (IPCThreadState::self()->getCallingUid() != AID_AUDIOSERVER || shared == 0) {
47 return;
48 }
49 Mutex::Autolock _l(mLock);
50 for (size_t i = 0; i < mNamedReaders.size(); ) {
51 if (mNamedReaders[i].reader()->isIMemory(shared)) {
52 mNamedReaders.removeAt(i);
53 } else {
54 i++;
55 }
56 }
57 }
58
dumpTryLock(Mutex & mutex)59 bool MediaLogService::dumpTryLock(Mutex& mutex)
60 {
61 bool locked = false;
62 for (int i = 0; i < kDumpLockRetries; ++i) {
63 if (mutex.tryLock() == NO_ERROR) {
64 locked = true;
65 break;
66 }
67 usleep(kDumpLockSleepUs);
68 }
69 return locked;
70 }
71
dump(int fd,const Vector<String16> & args __unused)72 status_t MediaLogService::dump(int fd, const Vector<String16>& args __unused)
73 {
74 // FIXME merge with similar but not identical code at services/audioflinger/ServiceUtilities.cpp
75 static const String16 sDump("android.permission.DUMP");
76 if (!(IPCThreadState::self()->getCallingUid() == AID_AUDIOSERVER ||
77 PermissionCache::checkCallingPermission(sDump))) {
78 dprintf(fd, "Permission Denial: can't dump media.log from pid=%d, uid=%d\n",
79 IPCThreadState::self()->getCallingPid(),
80 IPCThreadState::self()->getCallingUid());
81 return NO_ERROR;
82 }
83
84 Vector<NamedReader> namedReaders;
85 {
86 bool locked = dumpTryLock(mLock);
87
88 // failed to lock - MediaLogService is probably deadlocked
89 if (!locked) {
90 String8 result(kDeadlockedString);
91 if (fd >= 0) {
92 write(fd, result.string(), result.size());
93 } else {
94 ALOGW("%s:", result.string());
95 }
96 return NO_ERROR;
97 }
98 namedReaders = mNamedReaders;
99 mLock.unlock();
100 }
101
102 for (size_t i = 0; i < namedReaders.size(); i++) {
103 const NamedReader& namedReader = namedReaders[i];
104 if (fd >= 0) {
105 dprintf(fd, "\n%s:\n", namedReader.name());
106 } else {
107 ALOGI("%s:", namedReader.name());
108 }
109 namedReader.reader()->dump(fd, 0 /*indent*/);
110 }
111 return NO_ERROR;
112 }
113
onTransact(uint32_t code,const Parcel & data,Parcel * reply,uint32_t flags)114 status_t MediaLogService::onTransact(uint32_t code, const Parcel& data, Parcel* reply,
115 uint32_t flags)
116 {
117 return BnMediaLogService::onTransact(code, data, reply, flags);
118 }
119
120 } // namespace android
121