Android系统启动流程

public class ProcessMonitorService extends Service {
    private static final String TAG = "ProcessMonitor";
    private Handler mHandler = new Handler();
    private static final long CHECK_INTERVAL = 5000; // 5秒检查一次
 
    @Override
    public void onCreate() {
        super.onCreate();
        startMonitor();
    }
 
    private void startMonitor() {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                checkProcesses();
                mHandler.postDelayed(this, CHECK_INTERVAL);
            }
        }, CHECK_INTERVAL);
    }
 
    private void checkProcesses() {
        ActivityManager am = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
        List<ActivityManager.RunningAppProcessInfo> processes = am.getRunningAppProcesses();
        
        for (ActivityManager.RunningAppProcessInfo process : processes) {
            // 检查进程状态
            Debug.MemoryInfo[] memInfo = am.getProcessMemoryInfo(
                    new int[]{process.pid});
            if (memInfo != null && memInfo.length > 0) {
                int totalPss = memInfo[0].getTotalPss();
                Log.d(TAG, "Process: " + process.processName +
                        " Memory: " + totalPss + "KB");
            }
        }
    }
 
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
 
    @Override
    public void onDestroy() {
        super.onDestroy();
        mHandler.removeCallbacksAndMessages(null);
    }
}

public class ColdStartMonitor {
    private static final String TAG = "ColdStartMonitor";
    private static long sStartTime;
    private static final List<TimeRecord> sTimeRecords = new ArrayList<>();
 
    public static void markStartTime() {
        sStartTime = System.currentTimeMillis();
    }
 
    public static void markStage(String stageName) {
        long currentTime = System.currentTimeMillis();
        long duration = currentTime - sStartTime;
        sTimeRecords.add(new TimeRecord(stageName, duration));
        Log.d(TAG, stageName + " cost: " + duration + "ms");
    }
 
    public static void printSummary() {
        StringBuilder sb = new StringBuilder("Cold Start Summary:\n");
        long totalTime = 0;
        for (TimeRecord record : sTimeRecords) {
            sb.append(record.stageName)
              .append(": ")
              .append(record.timeCost)
              .append("ms\n");
            totalTime += record.timeCost;
        }
        sb.append("Total time: ").append(totalTime).append("ms");
        Log.i(TAG, sb.toString());
    }
 
    private static class TimeRecord {
        String stageName;
        long timeCost;
 
        TimeRecord(String stageName, long timeCost) {
            this.stageName = stageName;
            this.timeCost = timeCost;
        }
    }
}
 
// 使用示例
public class MyApplication extends Application {
    @Override
    public void onCreate() {
        ColdStartMonitor.markStartTime();
        super.onCreate();
        
        // 初始化各种SDK
        initSDKs();
        ColdStartMonitor.markStage("Init SDKs");
        
        // 预加载数据
        preloadData();
        ColdStartMonitor.markStage("Preload Data");
        
        // 应用启动完成
        ColdStartMonitor.markStage("Application Created");
        ColdStartMonitor.printSummary();
    }
}