Android ANR log trace日志文件分析

Trace文件怎么获取?

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.(log路径:/data/system/dropbox)

获取系统crash log: adb shell dumpsys dropbox –print >>log.txt

系统生成的Trace文件保存在data/anr,可以用过命令adb pull data/anr/取出

Trace文件怎么生成的?

当APP(包括系统APP和用户APP)进程出现ANR、应用响应慢或WatchDog的监视没有得到回馈时,系统会dump此时的top进程,进程中Thread的运行状态就都dump到这个Trace文件中了.

导致ANR的常见几种情况:
  • KeyDispatchTimeout(5s): 按键或触摸事件在特定时间内无法处理完成
  • BroadcastTimeout(10s): 广播在特定时间内无法处理完成
  • ServiceTimeout(20s): Service在特定的时间无法处理完成 另外还有ProviderTimeout和WatchDog等导致的ANR

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) {
        ArrayList<Integer> firstPids = new ArrayList<Integer>(5);
        SparseArray<Boolean> lastPids = new SparseArray<Boolean>(20);
 
        if (mController != null) {
            try {
                // 0 == continue, -1 = kill process immediately
                int res = mController.appEarlyNotResponding(app.processName, app.pid, annotation);
                if (res < 0 && app.pid != MY_PID) {
                    app.kill("anr", true);
                }
            } catch (RemoteException e) {
                mController = null;
                Watchdog.getInstance().setActivityController(null);
            }
        }
 
        long anrTime = SystemClock.uptimeMillis();
        if (MONITOR_CPU_USAGE) {
            updateCpuStatsNow();    // 更新CPU使用率
        }
 
        synchronized (this) {
            // PowerManager.reboot() can block for a long time, so ignore ANRs while shutting down.
            if (mShuttingDown) {
                Slog.i(TAG, "During shutdown skipping ANR: " + app + " " + annotation);
                return;
            } else if (app.notResponding) {
                Slog.i(TAG, "Skipping duplicate ANR: " + app + " " + annotation);
                return;
            } else if (app.crashing) {
                Slog.i(TAG, "Crashing app skipping ANR: " + app + " " + annotation);
                return;
            }
 
            // In case we come through here for the same app before completing
            // this one, mark as anring now so we will bail out.
            app.notResponding = true;
 
            // Log the ANR to the event log.
            EventLog.writeEvent(EventLogTags.AM_ANR, app.userId, app.pid,
                    app.processName, app.info.flags, annotation);
 
            // Dump thread traces as quickly as we can, starting with "interesting" processes.
            firstPids.add(app.pid);
 
            int parentPid = app.pid;
            if (parent != null && parent.app != null && parent.app.pid > 0) parentPid = parent.app.pid;
            if (parentPid != app.pid) firstPids.add(parentPid);
 
            if (MY_PID != app.pid && MY_PID != parentPid) firstPids.add(MY_PID);
 
            for (int i = mLruProcesses.size() - 1; i >= 0; i--) {
                ProcessRecord r = mLruProcesses.get(i);
                if (r != null && r.thread != null) {
                    int pid = r.pid;
                    if (pid > 0 && pid != app.pid && pid != parentPid && pid != MY_PID) {
                        if (r.persistent) {
                            firstPids.add(pid);
                        } else {
                            lastPids.put(pid, Boolean.TRUE);
                        }
                    }
                }
            }
        }
 
        // Log the ANR to the main log.
        StringBuilder info = new StringBuilder();
        info.setLength(0);
        info.append("ANR in ").append(app.processName);
        if (activity != null && activity.shortComponentName != null) {
            info.append(" (").append(activity.shortComponentName).append(")");
        }
        info.append("\n");
        info.append("PID: ").append(app.pid).append("\n");
        if (annotation != null) {
            info.append("Reason: ").append(annotation).append("\n");
        }
        if (parent != null && parent != activity) {
            info.append("Parent: ").append(parent.shortComponentName).append("\n");
        }
 
        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);
 
        if (mController != null) {
            try {
                // 0 == show dialog, 1 = keep waiting, -1 = kill process immediately
                int res = mController.appNotResponding(app.processName, app.pid, info.toString());
                if (res != 0) {
                    if (res < 0 && app.pid != MY_PID) {
                        app.kill("anr", true);
                    } else {
                        synchronized (this) {
                            mServices.scheduleServiceTimeoutLocked(app);
                        }
                    }
                    return;
                }
            } catch (RemoteException e) {
                mController = null;
                Watchdog.getInstance().setActivityController(null);
            }
        }
 
        // Unless configured otherwise, swallow ANRs in background processes & kill the process.
        boolean showBackground = Settings.Secure.getInt(mContext.getContentResolver(),
                Settings.Secure.ANR_SHOW_BACKGROUND, 0) != 0;
 
        synchronized (this) {
            mBatteryStatsService.noteProcessAnr(app.processName, app.uid);
 
            if (!showBackground && !app.isInterestingToUserLocked() && app.pid != MY_PID) {
                app.kill("bg anr", true);
                return;
            }
 
            // Set the app's notResponding state, and look up the errorReportReceiver
            makeAppNotRespondingLocked(app,
                    activity != null ? activity.shortComponentName : null,
                    annotation != null ? "ANR " + annotation : "ANR",
                    info.toString());
 
            //Set the trace file name to app name + current date format to avoid overrinding trace file
            String tracesPath = SystemProperties.get("dalvik.vm.stack-trace-file", null);
            if (tracesPath != null && tracesPath.length() != 0) {
                File traceRenameFile = new File(tracesPath);
                String newTracesPath;
                int lpos = tracesPath.lastIndexOf (".");
                if (-1 != lpos)
                    newTracesPath = tracesPath.substring (0, lpos) + "_" + app.processName + "_" + mTraceDateFormat.format(new Date()) + tracesPath.substring (lpos);
                else
                    newTracesPath = tracesPath + "_" + app.processName;
 
                traceRenameFile.renameTo(new File(newTracesPath));
            }
            // 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);
        }
    }

避免ANR?

  1. UI线程尽量只做跟UI相关的工作
  2. 耗时的工作(比如数据库操作,I/O,连接网络或者别的有可能阻碍UI线程的操作)把它放入单独的线程处理
  3. 尽量用Handler来处理UIthread和别的thread之间的交互

分析ANR的Log:

出现ANR的log如下:

06-22 10:37:46.204  3547  3604 E ActivityManager: ANR in org.code:MessengerService	// ANR出现的进程包名
 
E ActivityManager: PID: 17027		// ANR进程ID
 
E ActivityManager: Reason: executing service org.code/.ipc.MessengerService	//导致ANR的原因
 
E ActivityManager: Load: 8.31 / 8.12 / 8.47
 
E ActivityManager: CPU usage from 0ms to 6462ms later:	//CPU在ANR发生后的使用情况
 
E ActivityManager:   61% 3547/system_server: 21% user + 39% kernel / faults: 13302 minor 2 major
 
E ActivityManager:   0.2% 475/debuggerd: 0% user + 0.1% kernel / faults: 6086 minor 1 major
 
E ActivityManager:   10% 5742/com.android.phone: 5.1% user + 5.1% kernel / faults: 7597 minor
 
E ActivityManager:   6.9% 5342/com.android.systemui: 2.1% user + 4.8% kernel / faults: 4158 minor
 
E ActivityManager:   0.1% 477/debuggerd64: 0% user + 0.1% kernel / faults: 4013 minor
 
E ActivityManager:   5.7% 16313/org.code: 3.2% user + 2.4% kernel / faults: 2412 minor
 
E ActivityManager:   3.7% 17027/org.code:MessengerService: 1.7% user + 2% kernel / faults: 2571 minor 6 major
 
E ActivityManager:   2.6% 306/cfinteractive: 0% user + 2.6% kernel
					... ...
E ActivityManager:  +0% 17168/kworker/0:1: 0% user + 0% kernel
 
E ActivityManager: 0% TOTAL: 0% user + 0% kernel + 0% softirq	// CUP占用情况
 
E ActivityManager: CPU usage from 5628ms to 6183ms later:
 
E ActivityManager:   42% 3547/system_server: 17% user + 24% kernel / faults: 11 minor
 
E ActivityManager:     12% 3604/ActivityManager: 1.7% user + 10% kernel
 
E ActivityManager:     12% 3609/android.display: 8.7% user + 3.5% kernel
 
E ActivityManager:     3.5% 5304/Binder_6: 1.7% user + 1.7% kernel
 
E ActivityManager:     3.5% 5721/Binder_A: 1.7% user + 1.7% kernel
 
E ActivityManager:     3.5% 5746/Binder_C: 3.5% user + 0% kernel
 
E ActivityManager:     1.7% 3599/Binder_1: 0% user + 1.7% kernel
 
E ActivityManager:     1.7% 3600/Binder_2: 0% user + 1.7% kernel
 
I ActivityManager: Killing 17027:org.code:MessengerService/u0a85 (adj 1): bg anr
 
I art     : Wrote stack traces to '/data/anr/traces.txt'	//art这个TAG打印对traces操作的信息
 
D GraphicsStats: Buffer count: 9
 
W ActivityManager: Scheduling restart of crashed service org.code/.ipc.MessengerService in 1000ms
 

og打印了ANR的基本信息,我们可以分析CPU使用率得知ANR的简单情况;如果CPU使用率很高,接近100%,可能是在进行大规模的计算更可能是陷入死循环;如果CUP使用率很低,说明主线程被阻塞了,并且当IOwait很高,可能是主线程在等待I/O操作的完成.

对于ANR只是分析Log很难知道问题所在,我们还需要通过Trace文件分析stack调用情况.

 
----- pid 17027 at 2017-06-22 10:37:39 -----	// ANR出现的进程pid和时间(和上述log中pid一致)
Cmd line: org.code:MessengerService				// ANR出现的进程名
Build fingerprint: 'Homecare/qucii8976v3_64:6.0.1/pansen06141150:eng/test-keys'		// 下面记录系统版本,内存等状态信息
ABI: 'arm64'
Build type: optimized
Zygote loaded classes=6576 post zygote classes=13
Intern table: 13780 strong; 17 weak
JNI: CheckJNI is on; globals=283 (plus 158 weak)
Libraries: /system/lib64/libandroid.so /system/lib64/libcompiler_rt.so /system/lib64/libjavacrypto.so /system/lib64/libjnigraphics.so /system/lib64/libmedia_jni.so /system/lib64/libwebviewchromium_loader.so libjavacore.so (7)
Heap: 29% free, 8MB/12MB; 75731 objects
Dumping cumulative Gc timings
Total number of allocations 75731
Total bytes allocated 8MB
Total bytes freed 0B
Free memory 3MB
Free memory until GC 3MB
Free memory until OOME 183MB
Total memory 12MB
Max memory 192MB
Zygote space size 3MB
Total mutator paused time: 0
Total time waiting for GC to complete: 0
Total GC count: 0
Total GC time: 0
Total blocking GC count: 0
Total blocking GC time: 0
 
suspend all histogram:	Sum: 76us 99% C.I. 0.100us-28us Avg: 7.600us Max: 28us
DALVIK THREADS (15):
// Signal Catcher是记录traces信息的线程
// Signal Catche(线程名)、(daemon)表示守护进程、prio(线程优先级,默认是5)、tid(线程唯一标识ID)、Runnable(线程当前状态)
"Signal Catcher" daemon prio=5 tid=3 Runnable
//线程组名称、suspendCount、debugSuspendCount、线程的Java对象地址、线程的Native对象地址
  | group="system" sCount=0 dsCount=0 obj=0x12d8f0a0 self=0x5598ae55d0
  //sysTid是线程号(主线程的线程号和进程号相同)
  | sysTid=17033 nice=0 cgrp=default sched=0/0 handle=0x7fb2350450
  | state=R schedstat=( 4348125 172343 3 ) utm=0 stm=0 core=1 HZ=100
  | stack=0x7fb2254000-0x7fb2256000 stackSize=1013KB
  | held mutexes= "mutator lock"(shared held)
  native: #00 pc 0000000000489e28  /system/lib64/libart.so (art::DumpNativeStack(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, int, char const*, art::ArtMethod*, void*)+236)
  native: #01 pc 0000000000458fe8  /system/lib64/libart.so (art::Thread::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) const+220)
  native: #02 pc 0000000000465bc8  /system/lib64/libart.so (art::DumpCheckpoint::Run(art::Thread*)+688)
  native: #03 pc 0000000000466ae0  /system/lib64/libart.so (art::ThreadList::RunCheckpoint(art::Closure*)+276)
  native: #04 pc 000000000046719c  /system/lib64/libart.so (art::ThreadList::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)+188)
  native: #05 pc 0000000000467a84  /system/lib64/libart.so (art::ThreadList::DumpForSigQuit(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)+492)
  native: #06 pc 0000000000431194  /system/lib64/libart.so (art::Runtime::DumpForSigQuit(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)+96)
  native: #07 pc 000000000043e604  /system/lib64/libart.so (art::SignalCatcher::HandleSigQuit()+1256)
  native: #08 pc 000000000043f214  /system/lib64/libart.so (art::SignalCatcher::Run(void*)+452)
  native: #09 pc 0000000000068714  /system/lib64/libc.so (__pthread_start(void*)+52)
  native: #10 pc 000000000001c604  /system/lib64/libc.so (__start_thread+16)
  (no managed stack frames)
 
//main(线程名)、prio(线程优先级,默认是5)、tid(线程唯一标识ID)、Sleeping(线程当前状态)
"main" prio=5 tid=1 Sleeping
  | group="main" sCount=1 dsCount=0 obj=0x73132d10 self=0x5598a5f5e0
  //sysTid是线程号(主线程的线程号和进程号相同)
  | sysTid=17027 nice=0 cgrp=default sched=0/0 handle=0x7fb6db6fe8
  | state=S schedstat=( 420582038 5862546 143 ) utm=24 stm=18 core=6 HZ=100
  | stack=0x7fefba3000-0x7fefba5000 stackSize=8MB
  | held mutexes=
  // java 堆栈调用信息(这里可查看导致ANR的代码调用流程)(分析ANR最重要的信息)
  at java.lang.Thread.sleep!(Native method)
  - sleeping on <0x0c60f3c7> (a java.lang.Object)
  at java.lang.Thread.sleep(Thread.java:1031)
  - locked <0x0c60f3c7> (a java.lang.Object)	// 锁住对象0x0c60f3c7
  at java.lang.Thread.sleep(Thread.java:985)
  at android.os.SystemClock.sleep(SystemClock.java:120)
  at org.code.ipc.MessengerService.onCreate(MessengerService.java:63)	//导致ANR的代码
  at android.app.ActivityThread.handleCreateService(ActivityThread.java:2877)
  at android.app.ActivityThread.access$1900(ActivityThread.java:150)
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1427)
  at android.os.Handler.dispatchMessage(Handler.java:102)
  at android.os.Looper.loop(Looper.java:148)
  at android.app.ActivityThread.main(ActivityThread.java:5417)
  at java.lang.reflect.Method.invoke!(Native method)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

在log中显示的pid在traces文件中与之对应,然后通过查看堆栈调用信息分析ANR的代码.

上述ANR实际上在org.code.ipc.MessengerService.onCreate中63行调用SystemClock.sleep(10000)代码导致的;这是发生在Java层的,如果在native层,那么堆栈中就不会有相关调用的路径,这种情况只能在native层添加更多的Log,一步步来查找了


线程状态的分类: java中定义的线程状态:

    // libcore/libart/src/main/java/java/lang/Thread.java
    /**
     * A representation of a thread's state. A given thread may only be in one
     * state at a time.
     */
    public enum State {
        /**
         * The thread has been created, but has never been started.
         */
        NEW,
        /**
         * The thread may be run.
         */
        RUNNABLE,
        /**
         * The thread is blocked and waiting for a lock.
         */
        BLOCKED,
        /**
         * The thread is waiting.
         */
        WAITING,
        /**
         * The thread is waiting for a specified amount of time.
         */
        TIMED_WAITING,
        /**
         * The thread has been terminated.
         */
        TERMINATED
    }

两者可以看出在C代码中定义更为详细,Traces中显示的线程状态都是C代码定义的.我们可以通过查看线程状态对应的信息分析ANR问题.

如: TimedWaiting对应的线程状态是TIMED_WAITING

kTimedWaiting, // TIMED_WAITING TS_WAIT in Object.wait() with a timeout 执行了无超时参数的wait函数

kSleeping, // TIMED_WAITING TS_SLEEPING in Thread.sleep() 执行了带有超时参数的sleep函数

ZOMBIE                              线程死亡,终止运行
RUNNING/RUNNABLE                    线程可运行或正在运行
TIMED_WAIT                          执行了带有超时参数的wait、sleep或join函数
MONITOR                             线程阻塞,等待获取对象锁
WAIT                                执行了无超时参数的wait函数
INITIALIZING                        新建,正在初始化,为其分配资源
STARTING                            新建,正在启动
NATIVE                              正在执行JNI本地函数
VMWAIT                              正在等待VM资源
SUSPENDED                           线程暂停,通常是由于GC或debug被暂停

 

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