[Zope] Kid clicking and Zope thread deadlock

[Hung Jung Lu]

Yikes, I was affraid that I might get kid clicking problems in Zope. And now 
I got it. Help is needed.

"Kid clicking" is a technical term used in multimedia game programs, 
referring to firing multiple click events quickly. The most scary part is 
that under intense clicking, a multi-threaded program would go into 
dead-lock.

I have a Zope application running. When I kid-click on one button, it 
actually locks Zope up. This error does not happen when I run Zope in 
single-thread mode. So, for the bug seems to come from Zope thread 
dead-locking.

Good thing is that it is reproducible. So I will start to trace the origin 
of the deadlock, all the way down into Zope internals if necessary. But help 
will be appreciated.

My Zope is 2.1.6. More info: it happens both with Netscape and IE. More 
info: when kid clicking on the webpage, actual requests are sent to the Zope 
server, I see from the terminal 4 lines about

2000-06-30T00:29:43 PROBLEM(100) ZSybaseDA Changed database context to 
'master'.
Changed database context to 'mydatabase'.

and it then goes into deadlock. Not sure whether it's Sybase or Zope 
problem.

By the way: how can browsers be so stupid as to send requests out for each 
repeated button click? Shouldn't them lock up the webpage right away? 
Browsers do lock up after an anchor is clicked, but why don't they lock up 
after a button is clicked??!! Arrghh...

regards,

Hung Jung


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