1.IMediaDeathNotifier::getMediaPlayerService()
SortedVector< wp<IMediaDeathNotifier> > IMediaDeathNotifier::sObitRecipients; // establish binder interface to MediaPlayerService /*static*/const sp<IMediaPlayerService>& IMediaDeathNotifier::getMediaPlayerService() { LOGV("getMediaPlayerService"); Mutex::Autolock _l(sServiceLock); if (sMediaPlayerService.get() == 0) { sp<IServiceManager> sm = defaultServiceManager(); sp<IBinder> binder; do { binder = sm->getService(String16("media.player")); if (binder != 0) { break; } LOGW("Media player service not published, waiting..."); usleep(500000); // 0.5 s } while(true); if (sDeathNotifier == NULL) { sDeathNotifier = new DeathNotifier(); } binder->linkToDeath(sDeathNotifier); sMediaPlayerService = interface_cast<IMediaPlayerService>(binder); } LOGE_IF(sMediaPlayerService == 0, "no media player service!?"); return sMediaPlayerService; }
2.getService(const String16& name)
// ---------------------------------------------------------------------- class BpServiceManager : public BpInterface<IServiceManager> { public: BpServiceManager(const sp<IBinder>& impl) : BpInterface<IServiceManager>(impl) { } virtual sp<IBinder> getService(const String16& name) const { unsigned n; for (n = 0; n < 5; n++){ sp<IBinder> svc = checkService(name); if (svc != NULL) return svc; LOGI("Waiting for service %s...\n", String8(name).string()); sleep(1); } return NULL; } virtual sp<IBinder> checkService( const String16& name) const { Parcel data, reply; data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor()); data.writeString16(name); remote()->transact(CHECK_SERVICE_TRANSACTION, data, &reply); return reply.readStrongBinder(); } virtual status_t addService(const String16& name, const sp<IBinder>& service) { Parcel data, reply; data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor()); data.writeString16(name); data.writeStrongBinder(service); status_t err = remote()->transact(ADD_SERVICE_TRANSACTION, data, &reply); return err == NO_ERROR ? reply.readExceptionCode() : err; } virtual Vector<String16> listServices() { Vector<String16> res; int n = 0; for (;;) { Parcel data, reply; data.writeInterfaceToken(IServiceManager::getInterfaceDescriptor()); data.writeInt32(n++); status_t err = remote()->transact(LIST_SERVICES_TRANSACTION, data, &reply); if (err != NO_ERROR) break; res.add(reply.readString16()); } return res; } };
3. virtual status_t transact( uint32_t code,
const Parcel& data,
Parcel* reply,
uint32_t flags = 0);
status_t BpBinder::transact( uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) { // Once a binder has died, it will never come back to life. if (mAlive) { status_t status = IPCThreadState::self()->transact( mHandle, code, data, reply, flags); if (status == DEAD_OBJECT) mAlive = 0; return status; } return DEAD_OBJECT; }
4. status_t transact(int32_t handle,
uint32_t code, const Parcel& data,
Parcel* reply, uint32_t flags);
status_t IPCThreadState::transact(int32_t handle, uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) { status_t err = data.errorCheck(); flags |= TF_ACCEPT_FDS; IF_LOG_TRANSACTIONS() { TextOutput::Bundle _b(alog); alog << "BC_TRANSACTION thr " << (void*)pthread_self() << " / hand " << handle << " / code " << TypeCode(code) << ": " << indent << data << dedent << endl; } if (err == NO_ERROR) { LOG_ONEWAY(">>>> SEND from pid %d uid %d %s", getpid(), getuid(), (flags & TF_ONE_WAY) == 0 ? "READ REPLY" : "ONE WAY"); err = writeTransactionData(BC_TRANSACTION, flags, handle, code, data, NULL); } if (err != NO_ERROR) { if (reply) reply->setError(err); return (mLastError = err); } if ((flags & TF_ONE_WAY) == 0) { #if 0 if (code == 4) { // relayout LOGI(">>>>>> CALLING transaction 4"); } else { LOGI(">>>>>> CALLING transaction %d", code); } #endif if (reply) { err = waitForResponse(reply); } else { Parcel fakeReply; err = waitForResponse(&fakeReply); } #if 0 if (code == 4) { // relayout LOGI("<<<<<< RETURNING transaction 4"); } else { LOGI("<<<<<< RETURNING transaction %d", code); } #endif IF_LOG_TRANSACTIONS() { TextOutput::Bundle _b(alog); alog << "BR_REPLY thr " << (void*)pthread_self() << " / hand " << handle << ": "; if (reply) alog << indent << *reply << dedent << endl; else alog << "(none requested)" << endl; } } else { err = waitForResponse(NULL, NULL); } return err; }