tree 8a6e25ff2e37c9006a6473fc7f468bfde03f2ce3
parent 37424d4cb43f5deead52c178fb845f15a7c7e1c9
author Antonio Barone <syntonyze@gmail.com> 1674649526 +0100
committer Antonio Barone <syntonyze@gmail.com> 1674649526 +0100

Improve locking mechanism

The current GC script checks whether a non-stale gc.log.lock file
exists before aborting the execution of the current GC.

This is because another, concurrent GC process might be be executed by
jgit or cgit at the same time.

However, this is not enough to ensure that no other processes are
performing GC.

Also, jgit only creates the gc.log.lock when the GC is performed in the
background and thus we cannot rely _just_ on the existence of that
lockfile to abort this script's GC.

Improve the locking mechanism of the GC by:

- _explicitly_ locking when running this script (to ensure no concurrent
   runs of the GC script occur, i.e. scheduling errors)

- Not only checking the gc.log.lock file, but allowing _extra_ lockfiles
  to be configured through the usage of the `EXTRA_GC_LOCK_FILES`
  environment variable. This allows to account for external GC processes
  that also run GC against the same repository.

Change-Id: I9e56f8f7debaaf7798777061d9966e4a0a4f8f38