android.system.ErrnoException on SntpClient

[cesarnorena]

Using the 3.4 Rx version of the lib, with initializeNtp I get this error android.system.ErrnoException sendto failed: EPERM (Operation not permitted). This happens with a lot of Android versions and device brands.

Caused by android.system.ErrnoException: sendto failed: EPERM (Operation not permitted)
       at libcore.io.Linux.sendtoBytes(Linux.java)
       at libcore.io.Linux.sendto(Linux.java:225)
       at libcore.io.BlockGuardOs.sendto(BlockGuardOs.java:304)
       at libcore.io.IoBridge.sendto(IoBridge.java:569)
       at java.net.PlainDatagramSocketImpl.send(PlainDatagramSocketImpl.java:124)
       at java.net.DatagramSocket.send(DatagramSocket.java:721)
       at com.instacart.library.truetime.SntpClient.doubleMillis(SntpClient.java:10)
       at com.instacart.library.truetime.SntpClient.requestTime(SntpClient.java:116)
       at com.instacart.library.truetime.TrueTime.requestTime(TrueTime.java:133)
       at com.instacart.library.truetime.TrueTimeRx$4$1$2.subscribe(TrueTimeRx.java:211)
       at io.reactivex.internal.operators.flowable.FlowableCreate.subscribeActual(FlowableCreate.java:71)
       at io.reactivex.Flowable.subscribe(Flowable.java:14805)
       at io.reactivex.Flowable.subscribe(Flowable.java:14752)
       at io.reactivex.internal.operators.flowable.FlowableSubscribeOn$SubscribeOnSubscriber.run(FlowableSubscribeOn.java:82)
       at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:66)
       at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:57)
       at java.util.concurrent.FutureTask.run(FutureTask.java:266)
       at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
       at java.lang.Thread.run(Thread.java:764)

[dradding]

We've been experiencing this too. Any suggestions?

[calhouncole]

Us too. Any advice would be much appreciated.

[guyromb]

Same

[LosDanieloss]

Based on stacktrace and TrueTimeRx source code it looks like Flowable created for a flatmap tries to emit onNext after chain was disposed. If that's the case you could try "sweeping it under the rug" by using RxJavaPlugins.onError Ref. https://github.com/ReactiveX/RxJava/issues/4880

[LosDanieloss]

I believe I've found the issue. Inside SntpClient.java and TrueTime.java there are methods requestTime() throws IOException which are responsible for whole connection magic. In the one from SntpClient.java you can see:

catch (Exception e) {
    TrueLog.d(TAG, "---- SNTP request failed for " + ntpHost);
    throw e;
}

After checking Android docs it turns out that ErrnoException doesn't extends IOException and that is causing the crashes because TrueTimeRx wraps call to requestTime() and only expects to catch IOExpcetions. Any other exception is pushed forward to RxJavaPlugins.onError() to be handled which by default crashes as of RxJava2. I think changing requestTime() throws IOException to requestTime() throws Exception ( or even Throwable) should solve issue. I'd try to submit PR with this shortly.

[sixpi]

I'm not sure the requestTime() is capable of throwing ErrnoExceptions - requestTime() is calling socket.send(), which only throws IOExceptions. Sockets already catch ErrnoException and rethrow as IOException.

[LosDanieloss]

I'm afraid you are right @sixpi :( Will take a look at it once again if I found some free time. All help would be appreciated. So if you have some information don't hesitate to share

[radvansky-tomas]

Any update on this ?