lockfile: record the primary process.
authorJunio C Hamano <junkio@cox.net>
Sat, 21 Apr 2007 10:11:10 +0000 (03:11 -0700)
committerJunio C Hamano <junkio@cox.net>
Sat, 21 Apr 2007 18:55:23 +0000 (11:55 -0700)
commit5e635e396020cc08bc21a3e67c20c5294d6d13fd
treed11c19f13482c6b92de47ee80e79ebd28f1b6e13
parent6073ee85719be6d959e74aa667024fcbec44a588
lockfile: record the primary process.

The usual process flow is the main process opens and holds the lock to
the index, does its thing, perhaps spawning children during the course,
and then writes the resulting index out by releaseing the lock.

However, the lockfile interface uses atexit(3) to clean it up, without
regard to who actually created the lock.  This typically leads to a
confusing behaviour of lock being released too early when the child
exits, and then the parent process when it calls commit_lockfile()
finds that it cannot unlock it.

This fixes the problem by recording who created and holds the lock, and
upon atexit(3) handler, child simply ignores the lockfile the parent
created.

Signed-off-by: Junio C Hamano <junkio@cox.net>
cache.h
lockfile.c