This locking has been missing from the beginning of annex.pidlock.
It used to be possble, when two threads are doing conflicting things,
for both to run at the same time despite using locking. Seems likely
that nothing actually had a problem, but it was possible, and this
eliminates that possible source of failure.
Sponsored-by: Dartmouth College's Datalad project
That made eg git-annex get of an unlocked file hang until the
annex.pidlocktimeout and then fail.
This fix should be fully thread safe no matter what else git-annex is
doing.
Only using runsGitAnnexChildProcess in the one place it's known to be a
problem. Could audit for all places where git-annex runs itself as a child
and add it to all of them, later.
Some recent changes to use mask missed that async exceptions can still
be thrown inside it. The goal is to make sure a block of cleanup code
runs entirely, w/o being interrupted by an async exception, so use
uninterruptibleMask.
Also, converted a few to bracket, which is nicer.
Audited for openFile and openFd, and this fixes all the ones I found
where an async exception could prevent the file getting closed.
Except for the lock pool, which is a whole other can of worms.
This does not change the overall license of the git-annex program, which
was already AGPL due to a number of sources files being AGPL already.
Legally speaking, I'm adding a new license under which these files are
now available; I already released their current contents under the GPL
license. Now they're dual licensed GPL and AGPL. However, I intend
for all my future changes to these files to only be released under the
AGPL license, and I won't be tracking the dual licensing status, so I'm
simply changing the license statement to say it's AGPL.
(In some cases, others wrote parts of the code of a file and released it
under the GPL; but in all cases I have contributed a significant portion
of the code in each file and it's that code that is getting the AGPL
license; the GPL license of other contributors allows combining with
AGPL code.)
Needs ghc 7.6.1, so minimum base version increased slightly. All builds
are well above this version of ghc, and debian oldstable is as well.
Code that could use lambdacase can be found by running:
git grep -B 1 'case ' | less
and searching in less for "<-"
This commit was sponsored by andrea rota.
