file locking primitive

Cees de Groot cg at
Sat Jan 3 22:50:45 UTC 2004

David Gorisek <squeak-dev at> said:
>For example in VisualWorks the file locking primitive does not behave
>consistently between Linux and Windows version. Therefore OmniBase for
>VisualWorks (and for Smalltalk/X) keeps track of locks set on a file to
>prevent setting a lock twice (internally using a Dictionary).
A side effect of this is that this code on Squeak implements 'internal'
locking for OmniBase (at least, if I remember the code allright -
haven't looked at it since last summer), meaning that as long as you
open a database only from a single image, you should be safe. 

However, OmniBase also uses stuff like O_CREAT|O_EXCL (i.e. only create
a file if it doesn't exist), etcetera; stuff that Squeak certainly
doesn't implement (but then, does VW? OmniBase on VW seems to run fine
here under Linux).

Cees de Groot          <cg at>
tric, the new way           helpdesk/ticketing software, VoIP/CTI, 
                            web applications, custom development

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