[Zope-dev] thread safety in external methods

[Jim Fulton]

Robin Becker wrote:
> 
> My original reply to Michel shows that doing as you suggest in the
> external method isn't sufficient. If two calls hit the method together
> then two locks may be created simultaneously and then the lock doesn't
> work.

Oops. Good point.

> It seems that each invocation of an external method gets a private
> global space.

Right. External method files are *not* modules.  They should not depend on 
usual module semantics.

> I have to move the lock into an imported file to get a lock to work. And
> in fact you're right as soon as I have the imported file I can keep
> __ZGA there and not in __main__.

The right answer in a case like this is to use a product, 
not an external method.

Jim

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