Is there a way of finding out where my app threw an ANR (Application Not Responding). I took a look at the traces.txt file in /data and I see a trace for my application. This is what I see in the trace.
DALVIK THREADS:
"main" prio=5 tid=3 TIMED_WAIT
| group="main" sCount=1 dsCount=0 s=0 obj=0x400143a8
| sysTid=691 nice=0 sched=0/0 handle=-1091117924
at java.lang.Object.wait(Native Method)
- waiting on <0x1cd570> (a android.os.MessageQueue)
at java.lang.Object.wait(Object.java:195)
at android.os.MessageQueue.next(MessageQueue.java:144)
at android.os.Looper.loop(Looper.java:110)
at android.app.ActivityThread.main(ActivityThread.java:3742)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:497)
at dalvik.system.NativeStart.main(Native Method)
"Binder Thread #3" prio=5 tid=15 NATIVE
| group="main" sCount=1 dsCount=0 s=0 obj=0x434e7758
| sysTid=734 nice=0 sched=0/0 handle=1733632
at dalvik.system.NativeStart.run(Native Method)
"Binder Thread #2" prio=5 tid=13 NATIVE
| group="main" sCount=1 dsCount=0 s=0 obj=0x433af808
| sysTid=696 nice=0 sched=0/0 handle=1369840
at dalvik.system.NativeStart.run(Native Method)
"Binder Thread #1" prio=5 tid=11 NATIVE
| group="main" sCount=1 dsCount=0 s=0 obj=0x433aca10
| sysTid=695 nice=0 sched=0/0 handle=1367448
at dalvik.system.NativeStart.run(Native Method)
"JDWP" daemon prio=5 tid=9 VMWAIT
| group="system" sCount=1 dsCount=0 s=0 obj=0x433ac2a0
| sysTid=694 nice=0 sched=0/0 handle=1367136
at dalvik.system.NativeStart.run(Native Method)
"Signal Catcher" daemon prio=5 tid=7 RUNNABLE
| group="system" sCount=0 dsCount=0 s=0 obj=0x433ac1e8
| sysTid=693 nice=0 sched=0/0 handle=1366712
at dalvik.system.NativeStart.run(Native Method)
"HeapWorker" daemon prio=5 tid=5 VMWAIT
| group="system" sCount=1 dsCount=0 s=0 obj=0x4253ef88
| sysTid=692 nice=0 sched=0/0 handle=1366472
at dalvik.system.NativeStart.run(Native Method)
----- end 691 -----
How can I find out where the problem is? The methods in the trace are all SDK methods.
An ANR happens when some long operation takes place in the "main" thread. This is the event loop thread, and if it is busy, Android cannot process any further GUI events in the application, and thus throws up an ANR dialog.
Now, in the trace you posted, the main thread seems to be doing fine, there is no problem. It is idling in the MessageQueue, waiting for another message to come in. In your case the ANR was likely a longer operation, rather than something that blocked the thread permanently, so the event thread recovered after the operation finished, and your trace went through after the ANR.
Detecting where ANRs happen is easy if it is a permanent block (deadlock acquiring some locks for instance), but harder if it's just a temporary delay. First, go over your code and look for vunerable spots and long running operations. Examples may include using sockets, locks, thread sleeps, and other blocking operations from within the event thread. You should make sure these all happen in separate threads. If nothing seems the problem, use DDMS and enable the thread view. This shows all the threads in your application similar to the trace you have. Reproduce the ANR, and refresh the main thread at the same time. That should show you precisely whats going on at the time of the ANR
You can enable StrictMode in API level 9 and above.
StrictMode is most commonly used to catch accidental disk or network
access on the application's main thread, where UI operations are
received and animations take place. By keeping your application's main thread
responsive, you also prevent ANR dialogs from being shown to users.
public void onCreate() {
StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
.detectAll()
.penaltyLog()
.penaltyDeath()
.build());
super.onCreate();
}
using penaltyLog() you can watch the output of adb logcat while you
use your application to see the violations as they happen.
You are wondering which task hold a UI Thread. Trace file gives you a hint to find the task. you need investigate a state of each thread
State of thread
running - executing application code
sleeping - called Thread.sleep()
monitor - waiting to acquire a monitor lock
wait - in Object.wait()
native - executing native code
vmwait - waiting on a VM resource
zombie - thread is in the process of dying
init - thread is initializing (you shouldn't see this)
starting - thread is about to start (you shouldn't see this either)
Focus on SUSPENDED, MONITOR state. Monitor state indicates which thread is investigated and SUSPENDED state of the thread is probably main reason for deadlock.
Basic investigate steps
Find "waiting to lock"
you can find monitor state "Binder Thread #15" prio=5 tid=75 MONITOR
you are lucky if find "waiting to lock"
example : waiting to lock <0xblahblah> (a com.foo.A) held by threadid=74
You can notice that "tid=74" hold a task now. So go to tid=74
tid=74 maybe SUSPENDED state! find main reason!
trace does not always contain "waiting to lock". in this case it is hard to find main reason.
I've been learning android for the last few months, so I'm far from an expert, but I've been really disappointed with the documentation on ANRs.
Most of the advice seems to be geared towards avoiding them or fixing them by blindly looking through your code, which is great, but I couldn't find anything on analyzing the trace.
There are three things you really need to look for with ANR logs.
1) Deadlocks: When a thread is in the WAIT state, you can look through the details to find who it's "heldby=". Most of the time, it'll be held by itself, but if it's held by another thread, that's likely to be a danger sign. Go look at that thread and see what it's held by. You might find a loop, which is a clear sign that something has gone wrong. This is pretty rare, but it's the first point because when it happens, it's a nightmare
2) Main thread Waiting: If your main thread is in the WAIT state, check if it's held by another thread. This shouldn't happen, because your UI thread shouldn't be held by a background thread.
Both of these scenarios, mean you need to rework your code significantly.
3) Heavy operations on the main thread: This is the most common cause of ANRs, but sometimes one of the harder to find and fix. Look at the main thread details. Scroll down the stack trace and until you see classes you recognize (from your app). Look at the methods in the trace and figure out if you're making network calls, db calls, etc. in these places.
Finally, and I apologize for shamelessly plugging my own code, you can use the python log analyzer I wrote at https://github.com/HarshEvilGeek/Android-Log-Analyzer This will go through your log files, open ANR files, find deadlocks, find waiting main threads, find uncaught exceptions in your agent logs and print it all out on the screen in a relatively easy to read manner. Read the ReadMe file (which I'm about to add) to learn how to use it. It's helped me a ton in the last week!
You need to look for "waiting to lock" in /data/anr/traces.txt file
for more details: Engineer for High Performance with Tools from Android & Play (Google I/O '17)
Whenever you're analyzing timing issues, debugging often does not help, as freezing the app at a breakpoint will make the problem go away.
Your best bet is to insert lots of logging calls (Log.XXX()) into the app's different threads and callbacks and see where the delay is at. If you need a stacktrace, create a new Exception (just instantiate one) and log it.
What Triggers ANR?
Generally, the system displays an ANR if an application cannot respond to user input.
In any situation in which your app performs a potentially lengthy operation, you should not perform the work on the UI thread, but instead create a worker thread and do most of the work there. This keeps the UI thread (which drives the user interface event loop) running and prevents the system from concluding that your code has frozen.
How to Avoid ANRs
Android applications normally run entirely on a single thread by default the "UI thread" or "main thread"). This means anything your application is doing in the UI thread that takes a long time to complete can trigger the ANR dialog because your application is not giving itself a chance to handle the input event or intent broadcasts.
Therefore, any method that runs in the UI thread should do as little work as possible on that thread. In particular, activities should do as little as possible to set up in key life-cycle methods such as onCreate() and onResume(). Potentially long running operations such as network or database operations, or computationally expensive calculations such as resizing bitmaps should be done in a worker thread (or in the case of databases operations, via an asynchronous request).
Code: Worker thread with the AsyncTask class
private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {
// Do the long-running work in here
protected Long doInBackground(URL... urls) {
int count = urls.length;
long totalSize = 0;
for (int i = 0; i < count; i++) {
totalSize += Downloader.downloadFile(urls[i]);
publishProgress((int) ((i / (float) count) * 100));
// Escape early if cancel() is called
if (isCancelled()) break;
}
return totalSize;
}
// This is called each time you call publishProgress()
protected void onProgressUpdate(Integer... progress) {
setProgressPercent(progress[0]);
}
// This is called when doInBackground() is finished
protected void onPostExecute(Long result) {
showNotification("Downloaded " + result + " bytes");
}
}
Code: Execute Worker thread
To execute this worker thread, simply create an instance and call execute():
new DownloadFilesTask().execute(url1, url2, url3);
Source
http://developer.android.com/training/articles/perf-anr.html
Basic on #Horyun Lee answer, I wrote a small python script to help to investigate ANR from traces.txt.
The ANRs will output as graphics by graphviz if you have installed grapvhviz on your system.
$ ./anr.py --format png ./traces.txt
A png will output like below if there are ANRs detected in file traces.txt. It's more intuitive.
The sample traces.txt file used above was get from here.
Consider using the ANR-Watchdog library to accurately track and capture ANR stack traces in a high level of detail. You can then send them to your crash reporting library. I recommend using setReportMainThreadOnly() in this scenario. You can either make the app throw a non-fatal exception of the freeze point, or make the app force quit when the ANR happens.
Note that the standard ANR reports sent to your Google Play Developer console are often not accurate enough to pinpoint the exact problem. That's why a third-party library is needed.
not sure if this will help. My issue was the app crashes and freezes my devices then forced it to restart on devices with android 10 but runs fine with the android 6 nothing showed in the logcat. The crashes wasn't easy to reproduce and very unpredictable.
I spent almost 2 wks searching and troubleshooting with ANR but no avail.
Finally syncing the gradle fixed all issues..... rookie mistake.
Hope this would help someone.
my issue with ANR , after much work i found out that a thread was calling a resource that did not exist in the layout, instead of returning an exception , i got ANR ...
For published apps, Google play console itself shows Exact ANRs report like crash report. It will show you all the information which class or Thread is causing ANR, Occurances and all other details.
Your App Dashboard-> Explore Android Vitals Tab -> View Core Vitals Detail (ANR section)-> Select your apk or artifect vesrion -> Crashes and ANR page just select ANRs from drop down. It will list all the ANRs.
You can navigate to specific ANR and check details.
After searching for many solutions for solving ANR crashes on Android, I stumbled onto this link:
https://developer.android.com/studio/debug/bug-report
Connect your android device to a computer with ADB installed
Open terminal
Run the following command (replace "path" with where you want your zip folder saved e.g. ~/folder/report):
adb bugreport
This enabled me to access all ANR (anr* files) bug reports that gave me a full tracebacks under the folder:
FS -> data -> anr -> anr* files
I know this question is probably asked few times but I can not find a valid answer for my case.
In my logcat I get
D/AndroidRuntime﹕ Shutting down VM
W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x418337c0)
which indicates I have a crash somewhere, but I can not see it in log, there is no more information about the crash.
I have tried
adb server -kill, adb server-start.
I closed the adb from the proccess in Task Manager and closed AndroidStudio and started everything again (I tried restart windows too).
I am using CrashLytics in my application, but I do not receive crash there either, however TestFairy was able to give me finally some information which is application ANR and the next log (sorry about messy log)
java.lang.Object.wait(Native Method)
java.lang.Thread.parkFor(Thread.java:1231)
sun.misc.Unsafe.park(Unsafe.java:323)
java.util.concurrent.locks.LockSupport.park(LockSupport.java:157)
java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:813)
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:846)
java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1176)
java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:185)
java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:261)
com.google.android.gms.analytics.zzx.zzfj(Unknown Source)
com.google.android.gms.analytics.GoogleAnalytics.zzfj(Unknown Source)
com.google.android.gms.analytics.ExceptionReporter.uncaughtException(Unknown Source)
java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)
dalvik.system.NativeStart.main(Native Method)
so I tried to search around and some says it can be a crash in GoogleAnalytics while trying to report another crash. so I disabled this code
UncaughtExceptionHandler myHandler = new ExceptionReporter(
mTracker,Thread.getDefaultUncaughtExceptionHandler(),
getContext().getApplicationContext());
Thread.setDefaultUncaughtExceptionHandler(myHandler);
I know that this issue happens after trying to open a fragment but when I debug the fragment is not started yet.
The problem is I still can not see any more information, so How can I see log or more information? Thanks and sorry for long post.
An ANR will occur if you are running a process on the UI thread which takes a long time, usually around 5 seconds. During this time the GUI (Graphical User Interface) will lock up which will result in anything the user presses will not be actioned. After the 5 seconds approx has occurred, if the thread still hasn't recovered then an ANR dialogue box is shown informing the user that the application is not responding and will give the user the choice to either wait, in the hope that the app will eventually recover, or to force close the app.
In my own testing I did not encounter this issue but once my app was published the ANRs started flooding in. My app currently has 22 ANRs with some being reported as many 100 times. All of the traces seem to be from attempting to create a new Realm instance on the UI thread.
"main" prio=5 tid=1 MONITOR
| group="main" sCount=1 dsCount=0 obj=0x4183ede0 self=0x417548b8
| sysTid=19680 nice=0 sched=0/0 cgrp=apps handle=1073975684
| state=S schedstat=( 2816413167 710323137 3658 ) utm=215 stm=66 core=1
at io.realm.Realm.createAndValidate(Realm.java:~495)
- waiting to lock <0x41df9c98> held by tid=12 (IntentService[UASyncService])
at io.realm.Realm.create(Realm.java:486)
at io.realm.Realm.getInstance(Realm.java:404)
at io.realm.Realm.getInstance(Realm.java:366)
at io.realm.Realm.getInstance(Realm.java:347)
I believe the root of this issue is, as beeender mentioned, that I have an open Realm transaction in a worker thread which is blocking my attempts to get a Realm instance on the UI thread causing ANRs.
I will update again later after I have a solution.
*Edit: Added updated information.
Realm no longer has this issue.
For reference my solution at the time was:
Thanks to beeender for pointing me in the right direction and linking this PR https://github.com/realm/realm-java/pull/1297
Issue
When there is a pending Realm transaction, any call to Realm.getInstance on a different thread will block until the pending transaction has been committed or cancelled.
In my case I have an IntentService which populates my Realm with existing user data, meanwhile I try to display any current data by querying Realm on the UI thread. Although the queries are simple and don't cause any issues normally, if there is a pending transaction in the IntentService, calling Realm.getInstance will be blocked, blocking the UI thread, potentially causing an ANR.
My first attempt at a solution was to pull beeender's PR branch and create a jar. I believe this fix did get me one step further, allowing the Realm instance to be created without blocking, but the UI thread was still blocked by small transactions I was trying to perform on UI thread.
Solution
The solution I implemented involves several steps:
Create duplicate objects for all of my models. The duplicates do not extend RealmObject (since RealmObjects cannot be used across threads.)
Move all accesses to Realm onto background threads. Basically I wrapped my queries in AsyncTasks and added listeners which return the non-RealmObject version of the model.
Make more small transactions rather than fewer large transactions. Where previously I began and committed transactions on either side of a loop which created many new RealmObjects, I now begin and commit the transaction per object. The purpose of this is to reduce the total uninterrupted time that Realm may be in an open transaction state so my queries providing data for the UI can complete without having to wait as long.
Conclusion
I was initially hesitant to use Realm due to it still being in beta as well as the caveat that RealmObjects cannot be used across threads. After some tests I felt confident that I could perform simple queries on the UI thread without issue (still with a guilty feeling in my gut though.)
Overall Realm is a great project to keep an eye on but I feel that it is not ready for large scale commercial projects. Using Realm on this project may have saved some time upfront but it cost many displeased customers and a difficult to diagnose issue.
*Edit: Clarified issue.
Realm's introduction example shows them using an AsyncTask to do their reads and writes.
Any costly I/O, be it from the network, a database, or a large file should typically be kept off the main thread as it will cause a sluggish UI. Without seeing your code, I'd guess that if you're getting an ANR you're probably doing something too complex for the main thread.
I've a strange black screen problem at app restart after the app wasn't used for a while reported by users in the play store developer console with an ANR with a quite strange stack trace:
----- pid 2704 at 2013-08-15 09:08:32 -----
Cmd line: system_server
DALVIK THREADS:
(mutexes: tll=0 tsl=0 tscl=0 ghl=0 hwl=0 hwll=0)
"main" prio=5 tid=1 NATIVE
| group="main" sCount=1 dsCount=0 obj=0x400281b8 self=0xd088
| sysTid=2704 nice=0 sched=0/0 cgrp=default handle=-1345006464
| schedstat=( 29713532638 35237133707 131286 )
at com.android.server.SystemServer.init1(Native Method)
at com.android.server.SystemServer.main(SystemServer.java:918)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(...)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
at dalvik.system.NativeStart.main(Native Method)
...
and no thread with app code involved. I can kind of reproduce it on one of my test devices but it is quite random and takes really long to run into the error. But if I'm able to I get the following messages in the log of the device right after starting the app:
I/ActivityManager( 2704): Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.client.android/.ExampleMainActivity bnds=[125,494][235,632] } from pid 2908
W/ActivityManager( 2704): Receiver during timeout: BroadcastFilter{40b8b180 ReceiverList{40b8b108 32495 com.example.client.android/10107 remote:40b34b28}}
I/ActivityManager( 2704): Skipping duplicate ANR: ProcessRecord{40bfc8c0 32495:com.example.client.android/10107} Broadcast of Intent { act=android.intent.action.SCREEN_OFF flg=0x40000000 }
W/ActivityManager( 2704): Activity idle timeout for HistoryRecord{40578b78 com.example.client.android/.ExampleMainActivity}
I already googled around and found the following posts on StackOverflow concerning these messages:
Activity idle timeout for HistoryRecord?
Activity idle timeout for HistoryRecord
And the following post in google groups:
https://groups.google.com/forum/?fromgroups#!topic/android-developers/TfkPlN5b-ig
I checked for services, if there's anything heavy-weight in onReceive of the BroadcastReceivers but haven't found anything.
We use a OnGlobalChangeLayoutListener, which applied an View.invalidate() to work around a WebView repaint probelm which maybe could cause a draw-Looping. I removed it but still do get the problem.
Anyone maybe having the same problem and having an idea how to fix it or to isolate it? I'm pretty much out of ideas here and would love to understand what's going on here.
UPDATE
I forgot to mention: if this black screen problem happened the only way getting the app out of this is a forced stop of the application process. Otherwise the log lines get logged every time I try to start the app.
UPDATE 2
A more detailed description of what is happening as requested: The black screen occurs very randomly. It always happens at start of the app and if happened only a force stop gets the app out of this. It seems to happen only after the app wasn't used for a longer and was probably swapped out of memory. And it looks like only Android 2.x devices are affected although I'm not sure with this.
UPDATE 3
I've added a button which calls android.os.Process.killProcess(Process.myPid()); and if I call this again and again I've been able to reproduce it after some time, by starting the app and quitting it using the button. After some time (quite random), I get this right after quitting using the button:
E/JavaBinder( 2704): !!! FAILED BINDER TRANSACTION !!!
followed by a:
W/ActivityManager( 2704): Activity pause timeout for HistoryRecord{40976dd8 com.example.client.android/.ExampleMainActivity}
and next time I restart the app I just get a black screen and the log messages mentioned above. I've been unable to reproduce the same with an android 4.1 device, only with two 2.3 devices.
Googling around I found this:
http://androiddiscuss.com/1-android-discuss/42614.html
suggesting the binder transaction buffer is somewhat exhausted. We use the MediaPlayer, InApp-Billing and Google Cloud Messages which use binding. I removed all of them and still get into this error. Maybe someone knows other hidden binder related stuff to check for?
I was finally able to identify the faulty component: I recently updated the used Admob-SDK from 6.2.1 to 6.4.1 and the black screen (and the Java-Binder message) happens since the update. Rolling back to 6.2.1 solved the issue.