JOSM is reloading multiple times a modified validation file

[naoliv]

It seems that #15282 is back.
While saving a local validation file I can see that JOSM is reloading it 3 times:

2018-06-20 08:19:27.182 INFO: Source Brasil has been modified. Reloading it...
2018-06-20 08:19:27.222 INFO: Source Brasil has been modified. Reloading it...
2018-06-20 08:19:27.244 INFO: Source Brasil has been modified. Reloading it...

JOSM:

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2018-06-19 19:44:45 +0200 (Tue, 19 Jun 2018)
Revision:13959
Build-Date:2018-06-19 17:47:20
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (13959 en) Linux Debian GNU/Linux testing (buster)
Memory Usage: 871 MB / 7168 MB (690 MB allocated, but free)
Java version: 10.0.1+10-Debian-4, Oracle Corporation, OpenJDK 64-Bit Server VM
Screen: :0.0 1600x900, :0.1 1280x1024
Maximum Screen Size: 1600x1024
Java package: openjdk-10-jre:amd64-10.0.1+10-4
Java ATK Wrapper package: libatk-wrapper-java:all-0.33.3-21
VM arguments: [--add-modules=java.activation,java.se.ee, -Dawt.useSystemAAFontSettings=gasp]
Program arguments: [--language=en]
Dataset consistency test: No problems found

[Don-vip]

I can't reproduce with same version of Java and Windows. Do you have another machine with a different OS to see if it's specific to Debian?

[naoliv]

Sure, I will see if I can test it using a live CD of another distro.
But doing some more tests:

• With a simple touch I can see that JOSM only reloads it a single time

  2018-06-20 14:11:50.482 INFO: Source Brasil has been modified. Reloading it...
  

• Only opening the file for edition (without editing or saving it) I see 3 events:

  2018-06-20 14:13:21.537 FINE: Received ENTRY_CREATE event for unregistered file: /arquivos/git/validador-josm/.Rules_Brazilian-Specific.validator.mapcss.swp
  2018-06-20 14:13:21.538 FINE: Received ENTRY_CREATE event for unregistered file: /arquivos/git/validador-josm/.Rules_Brazilian-Specific.validator.mapcss.swp
  2018-06-20 14:13:21.538 FINE: Received ENTRY_MODIFY event for unregistered file: /arquivos/git/validador-josm/.Rules_Brazilian-Specific.validator.mapcss.swp
  

• Saving the file (without closing it):

  2018-06-20 14:14:06.548 FINE: Received ENTRY_CREATE event for unregistered file: /arquivos/git/validador-josm/Rules_Brazilian-Specific.validator.mapcss~
  2018-06-20 14:14:06.548 FINE: Received ENTRY_MODIFY event for unregistered file: /arquivos/git/validador-josm/.Rules_Brazilian-Specific.validator.mapcss.swp
  2018-06-20 14:14:06.590 FINE: Received ENTRY_MODIFY event for unregistered file: /arquivos/git/validador-josm/.Rules_Brazilian-Specific.validator.mapcss.swp
  2018-06-20 14:14:06.633 INFO: Source Brasil has been modified. Reloading it...
  2018-06-20 14:14:06.718 INFO: Source Brasil has been modified. Reloading it...
  

• Saving and closing:

  2018-06-20 14:15:11.956 FINE: Received ENTRY_CREATE event for unregistered file: /arquivos/git/validador-josm/Rules_Brazilian-Specific.validator.mapcss~
  2018-06-20 14:15:11.957 INFO: Source Brasil has been modified. Reloading it...
  2018-06-20 14:15:11.978 INFO: Source Brasil has been modified. Reloading it...
  2018-06-20 14:15:11.999 INFO: Source Brasil has been modified. Reloading it...
  2018-06-20 14:15:12.046 INFO: Source Brasil has been modified. Reloading it...
  

Maybe it could be related with the ENTRY_CREATE and ENTRY_MODIFY of the unrelated .mapcss.swp and .mapcss~ files?
ie, JOSM is receiving an unrelated event and reloading the validation file.

[Don-vip]

Ah! What text editor are you using to modify the file?

[naoliv]

I am using vim
Maybe it's possible to watch only the registered file or ignore any unrelated event?

[Don-vip]

It seems Linux ​behaves differently than what I can see on Windows:

WatcherServices reports events twice because the underlying file is updated twice. Once for the content and once for the file modified time. These events happen within a short time span. To solve this, sleep between the poll() or take() calls and the key.pollEvents() call.