Multiple Application Instances Opening same local db file

[Ruslan Zasukhin]

On 2/27/11 7:02 PM, "Ernesto Giannotta" <erne at apimac.com> wrote:

Hi Guys,

>>> Is there a way to tell the file has already been open?
>> 
>> On linux exists   technique of lock file.

>> YOUR family of apps, can follow to rule
>> That app check for my_db.lck file
>> If not found then it can open it and create such lock file.
>> 
>> All others will see lock file and not touch db.
>> E.g. Archicad do this on WIN and MAC ...
> 
> in Cocoa when I try to open an already open DB Vale gracefully throws an
> NSException whose name is:
> 
> File "Untitled Notes.notepad" cannot be opened because it is used by another
> application.
> 
> How does she know?

Ops,  I really have point linux-only way.

On MAC OS X and Windows all is simpler.
    Valentina engine open local db files in the EXCLUSIVE mode,
    so other apps if try will get back OS error -- file is busy.


> BTW why you set the name and not the reason with this info?

?


-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]