Android ANR/Crash Log日志分析技巧总结(建议收藏)

推荐阅读

ANR日志Trace文件获取

系统生成的Trace文件保存在data/anr

adb pull data/anr/

traces.txt只保留最后一次ANR的信息

Android系统有个DropBox功能功能,它能记录系统出现的crash错误，因此保留有发生过的ANR的信息

/data/system/dropbox

获取系统Crash Log

adb shell dumpsys dropbox --print >>log.txt

导致ANR的常见几种情况

1.Input dispatching timed out(5 seconds)按键或触摸事件处理超时(一般是UI主线程做了耗时的操作,这类ANR最常见)

2.BroadcastTimeout(10 seconds)广播的分发和处理超时(一般是onReceiver执行时间过长)

3.ServiceTimeout(20 seconds)Service的启动和执行超时

另外还有ProviderTimeout和WatchDog等导致的ANR.还有当系统内存或CPU资源不足时容易出现ANR,一般这种情况会有lowmemorykill的log打印

应用ANR产生的时候,ActivityManagerService的appNotResponding方法就会被调用,然后在/data/anr/traces.txt文件中写入ANR相关信息

final void appNotResponding(ProcessRecord app, ActivityRecord activity,
    ActivityRecord parent, boolean aboveSystem, final String annotation) {
  // ... ...
  if (MONITOR_CPU_USAGE) {
    updateCpuStatsNow();    // 更新CPU使用率
  }
  // ... ...
  final ProcessCpuTracker processCpuTracker = new ProcessCpuTracker(true);
  // dumpStackTraces是输出traces文件的函数
  File tracesFile = dumpStackTraces(true, firstPids, processCpuTracker, lastPids,
      NATIVE_STACKS_OF_INTEREST);

  String cpuInfo = null;
  if (MONITOR_CPU_USAGE) {
    updateCpuStatsNow();    // 再次更新CPU信息
    synchronized (mProcessCpuTracker) {
      // 输出ANR发生前一段时间内的CPU使用率
      cpuInfo = mProcessCpuTracker.printCurrentState(anrTime);
    }
    info.append(processCpuTracker.printCurrentLoad());
    info.append(cpuInfo);
  }
  // 输出ANR发生后一段时间内的CPU使用率
  info.append(processCpuTracker.printCurrentState(anrTime));

  Slog.e(TAG, info.toString());
  if (tracesFile == null) {
    // There is no trace file, so dump (only) the alleged culprit's threads to the log
    Process.sendSignal(app.pid, Process.SIGNAL_QUIT);
  }
  // 将ANR信息同时输出到DropBox中
  addErrorToDropBox("anr", app, app.processName, activity, parent, annotation,
      cpuInfo, tracesFile, null);
  // ... ...
  synchronized (this) {
    // 显示ANR提示对话框
    // Bring up the infamous App Not Responding dialog
    Message msg = Message.obtain();
    HashMap<String, Object> map = new HashMap<String, Object>();
    msg.what = SHOW_NOT_RESPONDING_MSG;
    msg.obj = map;
    msg.arg1 = aboveSystem ? 1 : 0;
    map.put("app", app);
    if (activity != null) {
      map.put("activity", activity);
    }
    mUiHandler.sendMessage(msg);
  }
}