Re: WO 5.4, Ajax polling and multi-threading questions
Re: WO 5.4, Ajax polling and multi-threading questions
- Subject: Re: WO 5.4, Ajax polling and multi-threading questions
- From: Mike Schrag <email@hidden>
- Date: Wed, 18 Feb 2009 09:46:06 -0500
we have WO applications that we run single-threaded because
"somebody told somebody years ago" that EOF would choke in a multi-
threaded environment.
also when i tried to open up multi-threading, i was made to
understand that EOF is not thread-safe; EOF is not good at locking
and bad things will happen, and hence I need to do the locking myself.
based on what you're describing, it appears that EOF will take care
of itself and i don't need to do a thing besides
-WOAllowsConcurrentRequestHandling YES -WOWorkerThreadCountMax 32
looks like i woke up on the right side of bed, if that's the case!
woah, ok ... hold on here ...
* IMPROPERLY LOCKED eof is not threadsafe
* PROPERLY LOCKED eof is threadsafe (well ... for the most part)
* you should only ever use EOF when you are locking properly
* not sure what "eof is not good at locking" means ... it does not
lock on its own (out of the box), so EOF is perfectly good at locking
when you tell it to do so
* EOF will NOT take care of itself -- you have to take care of EOF ...
if you take care of EOF, it will take care of you, and that means
always locking properly
* if you're always using session default editing context (which you
should not do), it will lock for you ... if you ever use another EC,
you have to lock or you're going to be screwed. this is why Wonder
implements automatic editing context locking, which has, for the vast
majority of cases, solved this problem. if you don't use Wonder, you
should at least be using MultiECLockManager, or something equivalent
-- you WILL shoot yourself in the foot otherwise.
* I have never (ever ever) had a WO app that runs with concurrent
request handling = false ... it disgusts me to think about it.
so to whomever told you that EOF isn't threadsafe and can be used
concurrently: "you're doing it wrong"
ms
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