android 源码分析--system-server

system_init.cpp 就是对系统服务启动进行使用的情况

extern "C" status_t system_init()
{
    LOGI("Entered system_init()");
    
    sp<ProcessState> proc(ProcessState::self());
    
    sp<IServiceManager> sm = defaultServiceManager();
    LOGI("ServiceManager: %p\n", sm.get());
    
    sp<GrimReaper> grim = new GrimReaper();
    sm->asBinder()->linkToDeath(grim, grim.get(), 0);
    
    char propBuf[PROPERTY_VALUE_MAX];
    property_get("system_init.startsurfaceflinger", propBuf, "1");
    if (strcmp(propBuf, "1") == 0) {
        // Start the SurfaceFlinger
        SurfaceFlinger::instantiate();
    }

// SurfaceFlinger的使用

    // On the simulator, audioflinger et al don't get started the
    // same way as on the device, and we need to start them here
    if (!proc->supportsProcesses()) {

        // Start the AudioFlinger
        AudioFlinger::instantiate();

        // Start the media playback service
        MediaPlayerService::instantiate();

        // Start the camera service
        CameraService::instantiate();

        // Start the audio policy service
        AudioPolicyService::instantiate();
    }

    // And now start the Android runtime.  We have to do this bit
    // of nastiness because the Android runtime initialization requires
    // some of the core system services to already be started.
    // All other servers should just start the Android runtime at
    // the beginning of their processes's main(), before calling
    // the init function.
    LOGI("System server: starting Android runtime.\n");
    
    AndroidRuntime* runtime = AndroidRuntime::getRuntime();

    LOGI("System server: starting Android services.\n");
    runtime->callStatic("com/android/server/SystemServer", "init2");
        
    // If running in our own process, just go into the thread
    // pool.  Otherwise, call the initialization finished
    // func to let this process continue its initilization.
    if (proc->supportsProcesses()) {
        LOGI("System server: entering thread pool.\n");
        ProcessState::self()->startThreadPool();
        IPCThreadState::self()->joinThreadPool();
        LOGI("System server: exiting thread pool.\n");
    }
    return NO_ERROR;
}