Hi Sig!
I found code, which uses MagmaOidManager in two different processes. I placed a check instead of Mutex in it, which throws error, if some other process instead of one, which was first who accessed it tries to deal with oids.
After running update, i found, that the only process, which accessing oid manager except one, which running update is running by magma itself:
See fork in MaObjectRepository>>flushCacheSoon.
After changing this method to:
flushCacheSoon self flushCritical: [ self commitCritical: [ self flushCache. applyProcess _ nil ] ]
there's no other processes who attempt to use oid manager from except one, which runs update.
So, the conclusion is obvious: flush causing problems.
Thanks for digging in and talking with code, this really helps us have a productive discussion.
Thankfully, I don't see evidence of any Magma bug in what you've submitted. Your #checkProcess does not account for the fact that flushCacheSoon is forked repeatedly. Your ifFalse: condition is being satisfied against a dead process that already finished out. To serve its intended purpose, you should check that the 'process' inst-var is not terminated, as in:
checkProcess process ifNil: [ process := Processor activeProcess ] ifNotNil: [ (process ~= Processor activeProcess and: [ process isTerminated not ] ]) ifTrue: [ self error: 'Multiple processes using id manager' ]. ]
I'd be surprised if you hit your error with this change.
Cris, please check the #flushCritical: code. I think it should not run inside a commit or parallel to commits if we want it to run it in standalone process. Otherwise magma disregards own rule which says that following is not allowed: session commit: [ [ some code ] fork ]
#flushCache does not run parallel with commits. See in #flushCacheSoon, the #flushCache is layered inside commitCritical:.
Also, i'm glad to note, that with changes in #flushCacheSoon, Florian able to run own update without errors regardless using my dictionaries or using stock classes.
You probably fixed it by something else.. flushCache does not even use MagmaOidManager, it just uses a standard OidManager.
But timing are different:
- out of the box magma: 18 minutes
- using my dictionaries: 8 minutes.
quite impressive for real world application isn't? :)
Indeed, I'd like the next release (r41) should be a performance release that includes improved Dictionary's if possible..
Cris, in attachment i placed the MagmaOidManager code, which checks the process. Just for case, if you want to see it yourself.
To make the test effective w.r.t. the flushCache code, you should move your 'process' variable, and #checkProcess up to MaOidManager and call it from that level rather than the Magma-specific subclass.
Regards, Chris