react-native-udp: Crash: Attempt to invoke virtual method 'void java.net.DatagramSocket.setReuseAddress(boolean)' on a null object reference

Description

App crashes if creating socket object is not successful (object equals to null). This issue is basically a copy of #119 as @Rapsssito asked to create a new one.

Error

com.tradle.react.UdpSocketClient.bind
UdpSocketClient.java, line 83
java.lang.NullPointerException: Attempt to invoke virtual method 'void java.net.DatagramSocket.setReuseAddress(boolean)' on a null object reference

Stack traces

com.tradle.react.UdpSocketClient.bind UdpSocketClient.java:83
com.tradle.react.UdpSockets$2.run UdpSockets.java:118
java.lang.Thread.run Thread.java:919
java.util.concurrent.ThreadPoolExecutor.runWorker ThreadPoolExecutor.java:1167
java.util.concurrent.ThreadPoolExecutor$Worker.run ThreadPoolExecutor.java:641
java.lang.Thread.run Thread.java:919

Steps to reproduce

Probably, you need to create and close sockets on and on. It is really hard to reproduce quickly.

Current behavior

App crashes on some devices with multiple Android versions. Sometimes the error is Attempt to invoke virtual method 'void java.net.DatagramSocket.send(java.net.DatagramPacket)' on a null object reference but the reason seems to be the same.

Expected behavior

App does not crash. The solution proposed by @rimzici is to surround the code responsible for crashing with a try/catch block (see the code in his fork: https://github.com/telldus/react-native-udp/blob/master/android/src/main/java/com/tradle/react/UdpSocketClient.java#L83-L91). However, maybe a better idea would be a simple null-checking?

Relevant information


react-native	0.63.4
react-native-udp	4.0.4 (but happens on earlier versions, too)

Occurred on


Device	OS
Galaxy S7	Android 8
Galaxy S9	Android 10
Galaxy S9+	Android 10
Galaxy S10+	Android 10

About this issue

Original URL
State: closed
Created 4 years ago
Comments: 15

Most upvoted comments

@Rapsssito Thank you for your hard work. It seems that #144 has also been fixed.

Let give the fix a couple of days more. We currently have about 18 000 active users so so far about ~15% of them installed and run the app. As I said, I will inform you about any crashes.

Thanks!

hubciorz on Jan 13, 2021

@Rapsssito I hope you had a nice Christmas!

We released an app update a couple of days ago and it seems to be much better. Just one crash in the new implementation so far:

Error

libcore.io.Posix.getsockoptLinger
Posix.java, line -2
java.util.concurrent.TimeoutException: java.net.PlainSocketImpl.finalize() timed out after 10 seconds

Stack traces

libcore.io.Posix.getsockoptLinger Posix.java
libcore.io.ForwardingOs.getsockoptLinger ForwardingOs.java:94
libcore.io.BlockGuardOs.isLingerSocket BlockGuardOs.java:105
libcore.io.BlockGuardOs.close BlockGuardOs.java:87
libcore.io.IoBridge.closeAndSignalBlockedThreads IoBridge.java:203
java.net.PlainSocketImpl.close PlainSocketImpl.java:148
java.net.PlainSocketImpl.finalize PlainSocketImpl.java:206
java.lang.Daemons$FinalizerDaemon.doFinalize Daemons.java:202
java.lang.Daemons$FinalizerDaemon.run Daemons.java:185
java.lang.Thread.run Thread.java:818

Occurred on


Device	OS
Nexus 7	Android 6.0.1

Tested by about 2000 users. I will keep you updated if I have more crash reports.

hubciorz on Jan 13, 2021

@Rapsssito We do not plan to release any app update before Christmas or New Year’s Eve so it has to wait until the first week of January.

hubciorz on Dec 21, 2020

@Rapsssito Sure. We are going to release an update to our app on Monday, so we will need then a couple of days to see if there are any crash reports. Thanks!

hubciorz on Dec 5, 2020