threads and database

[olivier vidal]

perfect !

thank you very much, Ruslan.

olivier

Le 24 juin 04, à 15:56, Ruslan Zasukhin a écrit :

> On 6/24/04 4:47 PM, "olivier vidal" <vidal_olivier at yahoo.fr> wrote:
>
>> thank you very much Marc and Ruslan.
>>
>> Imagine a shop.
>> In this shop, there is a single computer.
>> 4 screens and 4 mice are connected on this computer.
>
> You mean 4 physical monitors! Aha.
> Only 4 mice? What about keyboards?
>
> It look you try create old good terminals :-)
>
>> (4 screens : mode
>> "Extended Desktop" on Mac, with special graphics board. 4 screens
>> behave as a single screen.
>
> 4 monitors form a single virtual screen. Clear.
>
>> (Example: 4 screens with a resolution of
>> 1024X768 will give the illusion for the computer of a single screen of
>> 4096X768))
>>
>> Imagine a software (or driver) which allows the use of several mice
>> simultaneously on the same computer. Mice which can be simultaneously
>> clicked.
>
>> There are several salesmen and every salesman can use a screen and a
>> mouse ( a "virtual computer") to make a sale or for example see the
>> stock of an product.
>
>> The salesmen must be able to use "4 virtual computers" simultaneously.
>
>> Naturally, the software must be fast and it does not have to it have 
>> of
>> wait in the screen there.
>
> Ok
>
>> The idea is to use a single software on this computer.
>
> Yes, in this configuration you need SIGNLE APPLICATION
> Because you run like a single user for MacOS.
>
> You cannot start in MacOS 4 different copies of apps with the same 
> name,
> right? Although it is possible to make 4 copies of the same app with
> different names and run them all in the same time.
>
>> I also think that the best solution is to use a single window
>> distributed on 4 screens (a single window or a single application, so
>> that on 4 screens every window of screen is active and answers the
>> click first one).
>
> Single app, which allow open ANY number of windows.
> In your case will be opened 4 windows.
>
> Each window use own Valentina cursor.
> Each window play role of separate user.
> Each window may have own thread.
>
>> As there is only a single computer, I think effectively that the 
>> access
>> to the database should be very fast, even with 4 simultaneous attempts
>> of access.
>
> Exactly. No network. No any protocol or sockets.
>
> You set e.g. 20MB cache for Valentina.
> A lots of data in RAM.
>
>> Is it even really necessary in that case (for the database) to use
>> threads? (Ruslan, in realbasic threads is slow). There will be little
>> of update on the data, a great majority of cursors will be shared lock
>> (read only) and if it is not possible temporarily to access to data, I
>> can re-try in a loop. It should be very fast and there should be no
>> wait (I hope). ??
>
> Well. Then this is RB issue:
>     what is better: threads or timer.
>
> You can work with one thread, no problems.
> Cursors still are independent and lock records.
>
>> On the other hand, for the graphic interface and the posting, I 
>> suppose
>> that I should use threads. (Other solution?)
>>
>> I hope that Realsoftware is quickly going to correct the problem of
>> speed with threads.
>
> -- 
> Best regards,
> Ruslan Zasukhin      [ I feel the need...the need for speed ]
> -------------------------------------------------------------
> e-mail: ruslan at paradigmasoft.com
> web: http://www.paradigmasoft.com
>
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