From de919782f488a83b80d7c40896bf5b2596f1f65f Mon Sep 17 00:00:00 2001 From: Richard Purdie Date: Sun, 12 Jul 2020 11:44:07 +0100 Subject: server/process: Fix a rare lockfile race We're seeing rare occasional races on the autobuilder as if two server processes have the lockfile at the same time. We need to be extremely careful this does not happen. I think there is a potential race in this shutdown code since we delete the lockfile, then call unlockfile() which also tries to delete it. This means we may remove a lock file now held by another process if we're unlucky. Since unlockfile removes the lockfile when it can, just rely on that and remove any possible race window. An example cooker-deamonlog: --- Starting bitbake server pid 2266 at 2020-07-11 06:17:18.210777 --- Started bitbake server pid 2266 Entering server connection loop Accepting [] ([]) Processing Client Connecting Client Running command ['setFeatures', [2]] Running command ['updateConfig', XXX] Running command ['getVariable', 'BBINCLUDELOGS'] Running command ['getVariable', 'BBINCLUDELOGS_LINES'] Running command ['getSetVariable', 'BB_CONSOLELOG'] Running command ['getSetVariable', 'BB_LOGCONFIG'] Running command ['getUIHandlerNum'] Running command ['setEventMask', XXXX] Running command ['getVariable', 'BB_DEFAULT_TASK'] Running command ['setConfig', 'cmd', 'build'] Running command ['getVariable', 'BBTARGETS'] Running command ['parseFiles'] --- Starting bitbake server pid 8252 at 2020-07-11 06:17:28.584514 --- Started bitbake server pid 8252 --- Starting bitbake server pid 13278 at 2020-07-11 06:17:31.330635 --- Started bitbake server pid 13278 Running command ['dataStoreConnectorCmd', 0, 'getVar', ('BBMULTICONFIG',), {}] Running command ['getRecipes', ''] Running command ['clientComplete'] Processing Client Disconnecting Client No timeout, exiting. Exiting where it looks like there are two server processes running which should not be. In that build there was a process left sitting in memory with its bitbake.sock file missing but holding the lock (not sure why it wouldn't timeout/exit). Signed-off-by: Richard Purdie (cherry picked from commit e1a7c1821483031b224a1570bfe834da755219cc) Signed-off-by: Steve Sakoman --- lib/bb/server/process.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bb/server/process.py b/lib/bb/server/process.py index 83385baf6..475931a72 100644 --- a/lib/bb/server/process.py +++ b/lib/bb/server/process.py @@ -243,7 +243,7 @@ class ProcessServer(multiprocessing.Process): lock = bb.utils.lockfile(lockfile, shared=False, retry=False, block=True) if lock: # We hold the lock so we can remove the file (hide stale pid data) - bb.utils.remove(lockfile) + # via unlockfile. bb.utils.unlockfile(lock) return -- cgit 1.2.3-korg