平台:A33

Android4.4

Linux3.4

功能描述:实现重启的开机不播放开机铃声，按power键的开机播放开机铃声

一，无论关机还是重启都会经过rebootOrShutdown这个方法，在方法中通过参数reboot判断是否为重启，否则直接关机。在重启的那部分代码中新建一个文件/data/for_reboot_check.txt并写入"reboot"信息。注:文件创建在/sdcard目录中不合适，因为/sdcard目录是启动后期挂载的，在/system/目录中创建文件没有权限，所以选择在/data/目录中创建

代码路径：android/frameworks/base/services/java/com/android/server/power/ShutdownThread.java

/**     * Do not call this directly. Use {@link #reboot(Context, String, boolean)}     * or {@link #shutdown(Context, boolean)} instead.     *     * @param reboot true to reboot or false to shutdown     * @param reason reason for reboot     */    public static void rebootOrShutdown(boolean reboot, String reason) {        if (reboot) {    //if is reboot create a new file                        //add by jin,create a new file to store shutdown information            //=======================================================            String filenameTemp;            String path;            FileWriter writer = null;            filenameTemp = "/data"+"/for_reboot_check" + ".txt";    //file path            File filename = new File(filenameTemp);                Log.i(TAG, "----new file-----");            try{                if(!filename.exists()){                     filename.createNewFile();     //create a new file                      Log.i(TAG, "------create new file:"+ filenameTemp+"-----\n");                }                writer = new FileWriter(filename, false);                    writer.append("reboot");                         //write data to file                Log.i(TAG, "------writer data-----\n");                writer.flush();            //flush write cache                Log.i(TAG, "flush");                        writer.close();      //close writer            }catch(IOException e){                e.printStackTrace();            }finally{                if(null != writer){                }            }            //================================================================================                        Log.i(TAG, "Rebooting, reason: " + reason);            try {                PowerManagerService.lowLevelReboot(reason);            } catch (Exception e) {                Log.e(TAG, "Reboot failed, will attempt shutdown instead", e);            }        } else if (SHUTDOWN_VIBRATE_MS > 0) {            // vibrate before shutting down            Vibrator vibrator = new SystemVibrator();            try {                vibrator.vibrate(SHUTDOWN_VIBRATE_MS);            } catch (Exception e) {                // Failure to vibrate shouldn't interrupt shutdown.  Just log it.                Log.w(TAG, "Failed to vibrate during shutdown.", e);            }            // vibrator is asynchronous so we need to wait to avoid shutting down too soon.            try {                Thread.sleep(SHUTDOWN_VIBRATE_MS);            } catch (InterruptedException unused) {            }        }                IWindowManager  mWindowManager;                mWindowManager = IWindowManager.Stub.asInterface(ServiceManager.getService("window"));                if(mWindowManager != null ){                        try{                                if(isFreeze==1){                                        mWindowManager.thawRotation();                                        mWindowManager.updateRotation(true, true);                                        mWindowManager.setEventDispatching(false);                                }            }catch (RemoteException e) {            }                }        // Shutdown power        Log.i(TAG, "Performing low-level shutdown...");        PowerManagerService.lowLevelShutdown();    }

 

二，开机动画和开机铃声是由bootanimation应用实现的，在开机动画播放前读取/data/for_reboot_check.txt文件的内容，判断上次关机是否是重启，如果是重启则不播放开机铃声，

代码路径：android/frameworks/base/cmds/bootanimation/bootanimation_main.cpp

int main(int argc, char** argv){#if 1        //add by jin, for check reboot information         //=======================================================        FILE *file = NULL;        int ret = 0;        int flag = 0;  //用于判断是否是重启        char buf_read[10];        file = fopen("/data/for_reboot_check.txt", "rt+");        if(file == NULL){                printf("------file open failed----\n");                //return -1;        }else{                printf("------file open sucess----\n");                ret = fread(buf_read, sizeof(char), 6, file);                if(ret != 6)                {                        printf("----read failed:ret=%d----\n",ret);                }else{                        printf("-----%s----\n", buf_read);                        if(strncmp("reboot", buf_read, sizeof("reboot")) == 0){                                printf("------cmp sucess----\n");                                flag = 1;  //为重启，则flag置1                                                            if(remove("/data/for_reboot_check.txt") ==0)                                        printf("----remove file sucess----");                        }else{                                //return -1;                        }                }        }        #endif    //=============================================================== #if defined(HAVE_PTHREADS)    setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_DISPLAY);#endif    char value[PROPERTY_VALUE_MAX];    property_get("debug.sf.nobootanimation", value, "0");    int noBootAnimation = atoi(value);    ALOGI_IF(noBootAnimation,  "boot animation disabled");    if (!noBootAnimation) {        char cmd[PROPERTY_VALUE_MAX];        property_get("sys.shutdown_animation", cmd, "boot");        const char* url = "/system/media/boot.wav";        if (!strcmp(cmd, "shutdown")) {            url = "/system/media/shutdown.wav";        }        sp
     
       proc(ProcessState::self());        ProcessState::self()->startThreadPool();        // create the boot animation object        sp
      
        boot = new BootAnimation();                //add by jin, flag为0，则为关机后的启动，flag为1，则为重启后的启动        if(flag == 0){                boot->playBootMusic(url);        }        IPCThreadState::self()->joinThreadPool();    }    return 0;}
      
     

 

推荐博客：

                关于关机重启的流程分析：https://blog.csdn.net/lxl584685501/article/details/45747967