android - 解释 ANR 堆栈跟踪

Question

我正在使用 Android 中 PAHO 库中的 MQTT 客户端实现。有时，应用程序在尝试发布消息时锁定（我认为），我无法弄清楚发生了什么。

我也提前为所有长篇文章道歉。我真的不知道重要的部分是什么，所以“剧透”标签>! 无法隐藏细节。

MQTT 客户端在单独的线程中工作，但我正在从 UI 线程调用 mqtt 客户端实例。也许这会导致锁定？我是否应该将客户端定义为线程的实例并在线程中调用将操作转发给客户端的方法？

当应用程序挂起时，一段时间后 ANR 会启动并要求关闭应用程序。当我这样做时，我会从 /data/anr/traces.txt 中为我的进程获得以下堆栈跟踪：

DALVIK THREADS:
(mutexes: tll=0 tsl=0 tscl=0 ghl=0)
"main" prio=5 tid=1 WAIT
  | group="main" sCount=1 dsCount=0 obj=0x40a59460 self=0x109d828
  | sysTid=22050 nice=0 sched=0/0 cgrp=default handle=1074492552
  | schedstat=( 8524633000 459501000 2204 ) utm=827 stm=25 core=1
  at java.lang.Object.wait(Native Method)
  - waiting on <0x410f4bd0> (a java.lang.Object)
  at java.lang.Object.wait(Object.java:364)
  at org.eclipse.paho.client.mqttv3.internal.MqttDeliveryTokenImpl.waitUntilSent(MqttDeliveryTokenImpl.java:120)
  at org.eclipse.paho.client.mqttv3.internal.ClientComms.internalSend(ClientComms.java:85)
  at org.eclipse.paho.client.mqttv3.internal.ClientComms.sendNoWait(ClientComms.java:118)
  at org.eclipse.paho.client.mqttv3.MqttTopic.publish(MqttTopic.java:62)
  at se.chalmers.pd.dashboard.MqttWorker.publish(MqttWorker.java:177)
  at se.chalmers.pd.dashboard.ApplicationController.sendResponse(ApplicationController.java:238)
  at se.chalmers.pd.dashboard.ApplicationController.onLoadComplete(ApplicationController.java:358)
  at se.chalmers.pd.dashboard.MainActivity$CustomWebViewClient.onPageFinished(MainActivity.java:89)
  at android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:275)
  at android.os.Handler.dispatchMessage(Handler.java:99)
  at android.os.Looper.loop(Looper.java:137)
  at android.app.ActivityThread.main(ActivityThread.java:4424)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:511)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
  at dalvik.system.NativeStart.main(Native Method)

"Thread-3645" prio=5 tid=12 NATIVE
  | group="main" sCount=1 dsCount=0 obj=0x4111a5f8 self=0x13cc698
  | sysTid=22083 nice=0 sched=0/0 cgrp=default handle=19370528
  | schedstat=( 35731000 17350000 70 ) utm=1 stm=2 core=0
  at dalvik.system.NativeStart.run(Native Method)

"MQTT Client Callback" prio=5 tid=17 WAIT
  | group="main" sCount=1 dsCount=0 obj=0x41118bf0 self=0x13bb500
  | sysTid=22082 nice=0 sched=0/0 cgrp=default handle=20691280
  | schedstat=( 392860000 110613000 493 ) utm=35 stm=4 core=1
  at java.lang.Object.wait(Native Method)
  - waiting on <0x410d1c48> (a java.lang.Object)
  at java.lang.Object.wait(Object.java:364)
  at org.eclipse.paho.client.mqttv3.internal.MqttDeliveryTokenImpl.waitUntilSent(MqttDeliveryTokenImpl.java:120)
  at org.eclipse.paho.client.mqttv3.internal.ClientComms.internalSend(ClientComms.java:85)
  at org.eclipse.paho.client.mqttv3.internal.ClientComms.sendNoWait(ClientComms.java:118)
  at org.eclipse.paho.client.mqttv3.MqttTopic.publish(MqttTopic.java:62)
  at se.chalmers.pd.dashboard.MqttWorker.publish(MqttWorker.java:177)
  at se.chalmers.pd.dashboard.ApplicationController.sendResponse(ApplicationController.java:238)
  at se.chalmers.pd.dashboard.ApplicationController.handleSystemMessage(ApplicationController.java:210)
  at se.chalmers.pd.dashboard.ApplicationController.onMessage(ApplicationController.java:154)
  at se.chalmers.pd.dashboard.MqttWorker$1$CustomMqttCallback.notifyCallbacks(MqttWorker.java:133)
  at se.chalmers.pd.dashboard.MqttWorker$1$CustomMqttCallback.messageArrived(MqttWorker.java:128)
  at org.eclipse.paho.client.mqttv3.internal.CommsCallback.handleMessage(CommsCallback.java:248)
  at org.eclipse.paho.client.mqttv3.internal.CommsCallback.run(CommsCallback.java:139)
  at java.lang.Thread.run(Thread.java:856)

"MQTT Client Comms Sender" prio=5 tid=16 TIMED_WAIT
  | group="main" sCount=1 dsCount=0 obj=0x41118ae0 self=0x13bada0
  | sysTid=22081 nice=0 sched=0/0 cgrp=default handle=20689392
  | schedstat=( 6038000 11147000 189 ) utm=0 stm=0 core=0
  at java.lang.Object.wait(Native Method)
  - waiting on <0x410ffd90> (a java.lang.Object)
  at java.lang.Object.wait(Object.java:401)
  at org.eclipse.paho.client.mqttv3.internal.ClientState.get(ClientState.java:555)
  at org.eclipse.paho.client.mqttv3.internal.CommsSender.run(CommsSender.java:83)
  at java.lang.Thread.run(Thread.java:856)

"MQTT Client Comms Receiver" prio=5 tid=15 NATIVE
  | group="main" sCount=1 dsCount=0 obj=0x41116048 self=0x13ba870
  | sysTid=22080 nice=0 sched=0/0 cgrp=default handle=20619056
  | schedstat=( 656144000 184252000 2369 ) utm=59 stm=6 core=1
  at libcore.io.Posix.recvfromBytes(Native Method)
  at libcore.io.Posix.recvfrom(Posix.java:131)
  at libcore.io.BlockGuardOs.recvfrom(BlockGuardOs.java:164)
  at libcore.io.IoBridge.recvfrom(IoBridge.java:503)
  at java.net.PlainSocketImpl.read(PlainSocketImpl.java:488)
  at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
  at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:240)
  at libcore.io.Streams.readSingleByte(Streams.java:41)
  at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:236)
  at java.io.DataInputStream.readByte(DataInputStream.java:96)
  at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:51)
  at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:86)
  at java.lang.Thread.run(Thread.java:856)

"CookieSyncManager" prio=5 tid=14 NATIVE
  | group="main" sCount=1 dsCount=0 obj=0x410d0ad0 self=0x1286e20
  | sysTid=22066 nice=10 sched=0/0 cgrp=bg_non_interactive handle=19445224
  | schedstat=( 562000 10095000 5 ) utm=0 stm=0 core=0
  at android.os.MessageQueue.nativePollOnce(Native Method)
  at android.os.MessageQueue.next(MessageQueue.java:118)
  at android.os.Looper.loop(Looper.java:118)
  at android.webkit.WebSyncManager.run(WebSyncManager.java:90)
  at android.webkit.CookieSyncManager.run(CookieSyncManager.java:61)
  at java.lang.Thread.run(Thread.java:856)

"AsyncTask #1" prio=5 tid=13 WAIT
  | group="main" sCount=1 dsCount=0 obj=0x410d0920 self=0x121f5b0
  | sysTid=22065 nice=10 sched=0/0 cgrp=bg_non_interactive handle=19335920
  | schedstat=( 5753000 108824000 12 ) utm=0 stm=0 core=0
  at java.lang.Object.wait(Native Method)
  - waiting on <0x410d0ab8> (a java.lang.VMThread) held by tid=13 (AsyncTask #1)
  at java.lang.Thread.parkFor(Thread.java:1231)
  at sun.misc.Unsafe.park(Unsafe.java:323)
  at java.util.concurrent.locks.LockSupport.park(LockSupport.java:157)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2022)
  at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:413)
  at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1009)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1069)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
  at java.lang.Thread.run(Thread.java:856)

"WebViewCoreThread" prio=5 tid=11 NATIVE
  | group="main" sCount=1 dsCount=0 obj=0x410caa38 self=0x1266550
  | sysTid=22063 nice=0 sched=0/0 cgrp=default handle=18808064
  | schedstat=( 273871000 128721000 264 ) utm=20 stm=7 core=0
  at android.os.MessageQueue.nativePollOnce(Native Method)
  at android.os.MessageQueue.next(MessageQueue.java:118)
  at android.os.Looper.loop(Looper.java:118)
  at android.webkit.WebViewCore$WebCoreThread.run(WebViewCore.java:728)
  at java.lang.Thread.run(Thread.java:856)

"Binder Thread #2" prio=5 tid=10 NATIVE
  | group="main" sCount=1 dsCount=0 obj=0x410c1ef0 self=0x129de58
  | sysTid=22062 nice=0 sched=0/0 cgrp=default handle=19025912
  | schedstat=( 1983000 23992000 8 ) utm=0 stm=0 core=1
  at dalvik.system.NativeStart.run(Native Method)

"Binder Thread #1" prio=5 tid=9 NATIVE
  | group="main" sCount=1 dsCount=0 obj=0x410ba370 self=0x127cc90
  | sysTid=22061 nice=0 sched=0/0 cgrp=default handle=18949528
  | schedstat=( 2932000 32665000 18 ) utm=0 stm=0 core=0
  at dalvik.system.NativeStart.run(Native Method)

"FinalizerWatchdogDaemon" daemon prio=5 tid=8 TIMED_WAIT
  | group="main" sCount=1 dsCount=0 obj=0x410b6320 self=0x1227790
  | sysTid=22059 nice=0 sched=0/0 cgrp=default handle=19405328
  | schedstat=( 3721000 6943000 27 ) utm=0 stm=0 core=0
  at java.lang.VMThread.sleep(Native Method)
  at java.lang.Thread.sleep(Thread.java:1031)
  at java.lang.Thread.sleep(Thread.java:1013)
  at java.lang.Daemons$FinalizerWatchdogDaemon.run(Daemons.java:213)
  at java.lang.Thread.run(Thread.java:856)

"FinalizerDaemon" daemon prio=5 tid=7 WAIT
  | group="main" sCount=1 dsCount=0 obj=0x410b61c8 self=0x12207b8
  | sysTid=22058 nice=0 sched=0/0 cgrp=default handle=19405208
  | schedstat=( 1055000 601000 7 ) utm=0 stm=0 core=1
  at java.lang.Object.wait(Native Method)
  - waiting on <0x40a4f5d0> (a java.lang.ref.ReferenceQueue)
  at java.lang.Object.wait(Object.java:401)
  at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:102)
  at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:73)
  at java.lang.Daemons$FinalizerDaemon.run(Daemons.java:168)
  at java.lang.Thread.run(Thread.java:856)

"ReferenceQueueDaemon" daemon prio=5 tid=6 WAIT
  | group="main" sCount=1 dsCount=0 obj=0x410b6060 self=0x129d168
  | sysTid=22057 nice=0 sched=0/0 cgrp=default handle=19404976
  | schedstat=( 573000 395000 11 ) utm=0 stm=0 core=1
  at java.lang.Object.wait(Native Method)
  - waiting on <0x40a4f4f8> 
  at java.lang.Object.wait(Object.java:364)
  at java.lang.Daemons$ReferenceQueueDaemon.run(Daemons.java:128)
  at java.lang.Thread.run(Thread.java:856)

"Compiler" daemon prio=5 tid=5 VMWAIT
  | group="system" sCount=1 dsCount=0 obj=0x410b5f70 self=0x127c4d0
  | sysTid=22056 nice=0 sched=0/0 cgrp=default handle=19172728
  | schedstat=( 151015000 59330000 862 ) utm=9 stm=6 core=0
  at dalvik.system.NativeStart.run(Native Method)

"JDWP" daemon prio=5 tid=4 VMWAIT
  | group="system" sCount=1 dsCount=0 obj=0x410b5e88 self=0x12b39c8
  | sysTid=22055 nice=0 sched=0/0 cgrp=default handle=19323736
  | schedstat=( 4263000 2800000 18 ) utm=0 stm=0 core=1
  at dalvik.system.NativeStart.run(Native Method)

"Signal Catcher" daemon prio=5 tid=3 RUNNABLE
  | group="system" sCount=0 dsCount=0 obj=0x410b5d90 self=0x1268fd8
  | sysTid=22054 nice=0 sched=0/0 cgrp=default handle=19014912
  | schedstat=( 3760000 203000 4 ) utm=0 stm=0 core=1
  at dalvik.system.NativeStart.run(Native Method)

"GC" daemon prio=5 tid=2 VMWAIT
  | group="system" sCount=1 dsCount=0 obj=0x410b5cb0 self=0x12257d8
  | sysTid=22053 nice=0 sched=0/0 cgrp=default handle=19042944
  | schedstat=( 271726000 42594000 230 ) utm=26 stm=1 core=1
  at dalvik.system.NativeStart.run(Native Method)

----- end 22050 -----

我已经打开了严格模式，并且确实得到了一些痕迹，它会警告磁盘写入，但它们都不是特别长。这些是严格模式跟踪：

> >  04-30 10:29:50.053: D/StrictMode(22229): StrictMode policy violation;
> > ~duration=35 ms: android.os.StrictMode$StrictModeDiskReadViolation:
> > policy=31 violation=2 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.StrictMode$AndroidBlockGuardPolicy.onReadFromDisk(StrictMode.java:1089)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > libcore.io.BlockGuardOs.open(BlockGuardOs.java:106) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > libcore.io.IoBridge.open(IoBridge.java:390) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > java.io.FileOutputStream.(FileOutputStream.java:88) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.io.FileOutputStream.(FileOutputStream.java:73) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence.put(MqttDefaultFilePersistence.java:162)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientState.send(ClientState.java:397)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.internalSend(ClientComms.java:81)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.sendNoWait(ClientComms.java:118)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttTopic.publish(MqttTopic.java:62)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MqttWorker.publish(MqttWorker.java:177) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.sendResponse(ApplicationController.java:238)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.onLoadComplete(ApplicationController.java:358)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MainActivity$CustomWebViewClient.onPageFinished(MainActivity.java:95)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:275)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.Handler.dispatchMessage(Handler.java:99) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > android.os.Looper.loop(Looper.java:137) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > android.app.ActivityThread.main(ActivityThread.java:4424) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invokeNative(Native Method) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invoke(Method.java:511) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > dalvik.system.NativeStart.main(Native Method) 04-30 10:29:50.053:
> 
> 
> > D/StrictMode(22229): StrictMode policy violation; ~duration=26 ms:
> > android.os.StrictMode$StrictModeDiskWriteViolation: policy=31
> > violation=1 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:1063)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > libcore.io.BlockGuardOs.write(BlockGuardOs.java:190) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > libcore.io.IoBridge.write(IoBridge.java:447) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > java.io.FileOutputStream.write(FileOutputStream.java:187) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence.put(MqttDefaultFilePersistence.java:163)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientState.send(ClientState.java:397)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.internalSend(ClientComms.java:81)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.sendNoWait(ClientComms.java:118)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttTopic.publish(MqttTopic.java:62)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MqttWorker.publish(MqttWorker.java:177) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.sendResponse(ApplicationController.java:238)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.onLoadComplete(ApplicationController.java:358)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MainActivity$CustomWebViewClient.onPageFinished(MainActivity.java:95)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:275)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.Handler.dispatchMessage(Handler.java:99) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > android.os.Looper.loop(Looper.java:137) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > android.app.ActivityThread.main(ActivityThread.java:4424) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invokeNative(Native Method) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invoke(Method.java:511) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > dalvik.system.NativeStart.main(Native Method) 04-30 10:29:50.053:
> 
> 
> > D/StrictMode(22229): StrictMode policy violation; ~duration=18 ms:
> > android.os.StrictMode$StrictModeDiskWriteViolation: policy=31
> > violation=1 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:1063)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > libcore.io.BlockGuardOs.write(BlockGuardOs.java:190) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > libcore.io.IoBridge.write(IoBridge.java:447) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > java.io.FileOutputStream.write(FileOutputStream.java:187) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence.put(MqttDefaultFilePersistence.java:165)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientState.send(ClientState.java:397)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.internalSend(ClientComms.java:81)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.sendNoWait(ClientComms.java:118)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttTopic.publish(MqttTopic.java:62)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MqttWorker.publish(MqttWorker.java:177) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.sendResponse(ApplicationController.java:238)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.onLoadComplete(ApplicationController.java:358)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MainActivity$CustomWebViewClient.onPageFinished(MainActivity.java:95)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:275)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.Handler.dispatchMessage(Handler.java:99) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > android.os.Looper.loop(Looper.java:137) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > android.app.ActivityThread.main(ActivityThread.java:4424) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invokeNative(Native Method) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invoke(Method.java:511) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > dalvik.system.NativeStart.main(Native Method) 04-30 10:29:50.053:
> 
> 
> > D/StrictMode(22229): StrictMode policy violation; ~duration=2 ms:
> > android.os.StrictMode$StrictModeDiskWriteViolation: policy=31
> > violation=1 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:1063)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > libcore.io.BlockGuardOs.fsync(BlockGuardOs.java:96) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.io.FileDescriptor.sync(FileDescriptor.java:71) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence.put(MqttDefaultFilePersistence.java:167)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientState.send(ClientState.java:397)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.internalSend(ClientComms.java:81)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.internal.ClientComms.sendNoWait(ClientComms.java:118)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > org.eclipse.paho.client.mqttv3.MqttTopic.publish(MqttTopic.java:62)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MqttWorker.publish(MqttWorker.java:177) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.sendResponse(ApplicationController.java:238)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.ApplicationController.onLoadComplete(ApplicationController.java:358)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > se.chalmers.pd.dashboard.MainActivity$CustomWebViewClient.onPageFinished(MainActivity.java:95)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:275)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > android.os.Handler.dispatchMessage(Handler.java:99) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > android.os.Looper.loop(Looper.java:137) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > android.app.ActivityThread.main(ActivityThread.java:4424) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invokeNative(Native Method) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > java.lang.reflect.Method.invoke(Method.java:511) 04-30 10:29:50.053:
> > D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
> > 04-30 10:29:50.053: D/StrictMode(22229): at
> > com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 04-30
> > 10:29:50.053: D/StrictMode(22229): at
> > dalvik.system.NativeStart.main(Native Method)

编辑：这就是我启用 StrictMode 的方式

StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
        .detectAll()
        .penaltyLog()
        .build());

编辑 2：以供将来参考并添加问题的原因，我认为我应该在此处放置一些内容以供搜索引擎查找。

原来问题出在我们拥有的基于 Node.JS 的代理 mqttjs 上。这可能只是我们的实现，我还没有测试过 mqttjs 开发人员的示例。在发布了一定数量的消息后，代理停止发布和返回令牌。MQTT 客户端在另一个线程中运行，但由于它是从 UI 线程调用的，因此导致了一些问题。

无论如何，我们改用 Mosquitto，现在一切正常。

score 1 · Accepted Answer

您正在尝试在 UI 线程上进行长时间运行的网络通信。这会阻止 UI 更新，这很糟糕。Android 检测到这一事实并将其作为 ANR 处理。

我不知道你的代码是什么位，但这里的某个地方：

se.chalmers.pd.dashboard.ApplicationController.sendResponse(ApplicationController.java:238)

您应该将 MQTT 工作放在一个新线程中。如果您需要在 MQTT 工作完成后更新 UI，请使用 Handler。

score 1 · Accepted Answer

由于您启用了严格模式，因此在 UI 线程中不允许您访问磁盘或网络。

阅读您的堆栈跟踪，很明显对 MqttWorker.publish 的调用会导致磁盘访问。您应该将此调用放在 AsyncTask 或 UI 之外的另一个线程中。

score 1 · Accepted Answer

您的 ANR 发生在

org.eclipse.paho.client.mqttv3.internal.MqttDeliveryTokenImpl.waitUntilSent

因为这个方法调用Object.wait，可能是在等待另一个线程通知它。

你的电话显然在这里

se.chalmers.pd.dashboard.MqttWorker.publish(MqttWorker.java:177)

在您的 WebClient 实现中调用

se.chalmers.pd.dashboard.MainActivity$CustomWebViewClient.onPageFinished(MainActivity.java:89)

此onPageFinished方法在 UI 线程上调用。呼叫MqttTopic.publish是网络呼叫，显然会阻塞，直到呼叫完成。您应该将它放在 Thread 或 AsyncTask 中，这样它就不会锁定 UI 线程。

android - 解释 ANR 堆栈跟踪

3 回答 3

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