Android之SystemServer介绍（二）

    public static class MethodAndArgsCaller extends Exception
            implements Runnable {
        /** method to call */
        private final Method mMethod;

        /** argument array */
        private final String[] mArgs;

        public MethodAndArgsCaller(Method method, String[] args) {
            mMethod = method;
            mArgs = args;
        }

        public void run() {
            try {
                mMethod.invoke(null, new Object[] { mArgs });
            } catch (IllegalAccessException ex) {
                throw new RuntimeException(ex);
            } catch (InvocationTargetException ex) {
                Throwable cause = ex.getCause();
                if (cause instanceof RuntimeException) {
                    throw (RuntimeException) cause;
                } else if (cause instanceof Error) {
                    throw (Error) cause;
                }
                throw new RuntimeException(ex);
            }
        }
    }

    /**
     * The main entry point from zygote.
     */
    public static void main(String[] args) {
        new SystemServer().run();
    }

    private void run() {
        try {
            ……

            // 设置一些属性信息
            String timezoneProperty =  SystemProperties.get("persist.sys.timezone");
            if (timezoneProperty == null || timezoneProperty.isEmpty()) {
                Slog.w(TAG, "Timezone not set; setting to GMT.");
                SystemProperties.set("persist.sys.timezone", "GMT");
            }

            if (!SystemProperties.get("persist.sys.language").isEmpty()) {
                final String languageTag = Locale.getDefault().toLanguageTag();

                SystemProperties.set("persist.sys.locale", languageTag);
                SystemProperties.set("persist.sys.language", "");
                SystemProperties.set("persist.sys.country", "");
                SystemProperties.set("persist.sys.localevar", "");
            }
            ……
            // 设置消息looper
            Looper.prepareMainLooper();

            // 加载android_servers动态库
            System.loadLibrary("android_servers");
            performPendingShutdown();

            // 创建系统的context
            createSystemContext();

            // 创建SystemServiceManager服务，后续其对系统服务进行创建、启动和管理
            mSystemServiceManager = new SystemServiceManager(mSystemContext);
            // 设置SystemServiceManager的runtime
            mSystemServiceManager.setRuntimeRestarted(mRuntimeRestart);

            // 添加SystemServiceManager服务进入LocalServices队列
            LocalServices.addService(SystemServiceManager.class, mSystemServiceManager);
            SystemServerInitThreadPool.get();
        } finally {
            traceEnd();
        }

        try {
            traceBeginAndSlog("StartServices");
            // 启动引导服务
            startBootstrapServices();
            // 启动核心服务
            startCoreServices();
            // 启动其他服务
            startOtherServices();
            SystemServerInitThreadPool.shutdown();
        } catch (Throwable ex) {
            Slog.e("System", "******************************************");
            Slog.e("System", "************ Failure starting system services", ex);
            throw ex;
        } finally {
            traceEnd();
        }
        ……
    }

    private SystemServiceManager mSystemServiceManager;

    public void startService(@NonNull final SystemService service) {
        // Register it.
        mServices.add(service);
        // Start it.
        long time = System.currentTimeMillis();
        try {
            service.onStart();
        } catch (RuntimeException ex) {
            throw new RuntimeException("Failed to start service " + service.getClass().getName()
                    + ": onStart threw an exception", ex);
        }
        warnIfTooLong(System.currentTimeMillis() - time, service, "onStart");
    }

    private final ArrayList<SystemService> mServices = new ArrayList<SystemService>();