Merge lp:~invidian/intltool/fix-dangling-lock-file into lp:intltool

[Mateusz Gozdek]

Recently added https://bazaar.launchpad.net/~intltool/intltool/trunk/revision/748 right now leaves lock file after creating it, which breaks "distcheck" for some packages e.g. https://bugs.archlinux.org/index.php?do=details&action=details.addvote&task_id=67098.

This commit fixes that by unlinking the lock file after use.

[Mateusz Gozdek (invidian)]

I tested it locally on some builds and it works fine, but I can't confirm that it does not introduce a regression in race for which lock was originally added.

[Bernhard M. Wiedemann (ubuntubmw)]

In this case, it is probably OK to remove the lock file, since it is a one-time race.
After the first cache-writer is done, any amount of cache-readers can use the fully created caches.

The original problem was that cache-readers started to use partial caches before the cache-writer was done writing.

review: Approve

[Dan Nicholson (danbnicholson)]

> In this case, it is probably OK to remove the lock file, since it is a one-
> time race.
> After the first cache-writer is done, any amount of cache-readers can use the
> fully created caches.
>
> The original problem was that cache-readers started to use partial caches
> before the cache-writer was done writing.

I have to disagree here. flock works at the inode level, so when you delete the lock file, the next process to acquire the lock will open a new file and try to lock a different inode. We did this exact thing at Endless and it immediately broke. You really want the lock file to live as long as possible.

I think the correct fix is just to update the Makefile.in.in so that it cleans the lock file. Then you know at least all the processes make launched are done.

Unmerged revisions

749. By Mateusz Gozdek on 2021-04-08

intltool-merge.in: remove lock file after locking

=== modified file 'intltool-merge.in'
--- intltool-merge.in	2017-05-18 19:09:18 +0000
+++ intltool-merge.in	2021-04-08 17:37:42 +0000
@@ -401,6 +401,7 @@
         if ($cache_file_age <= &get_newest_po_age) 
         {
             close($lockfh);
+            unlink("$cache_file.lock");
             &load_cache;
             return;
         }
@@ -409,6 +410,7 @@
 
     &create_cache;
     close($lockfh);
+    unlink("$cache_file.lock");
 }
 
 sub add_translation