threads and database

[olivier vidal]

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. (4 screens : mode 
"Extended Desktop" on Mac, with special graphics board. 4 screens 
behave as a single screen. (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.

The idea is to use a single software on this computer.
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).
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.

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). ??

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.

thanks

olivier

Le 24 juin 04, à 11:37, Ruslan Zasukhin a écrit :

> On 6/24/04 10:53 AM, "olivier vidal" <vidal_olivier at yahoo.fr> wrote:
>
> Hi Oliver,
>
>> I use a new process which allows me to use several mice simultaneously
>> on several screens! (A mouse (a pointer) for every screen) (with a
>> single computer).
>>
>> Let us imagine that I use 4 screens for a software of reading and
>> modification of data. On every screen, a similar graphic interface
>> (Based on the spritesurface !) to read and modify data. On these 4
>> screens, we can click simultaneously to handle a database (Valentina).
>>
>> What is the best solution?:
>>
>>
>> 1- Several applications customers working simultaneously (an app on
>> every screen) handled with Valentina server?
>> ( I am afraid that the interface is too slow)
>
> Vserver + few client apps is the most right solution for this.
>
>> 2- A single application with four windows (one by screen), every 
>> window
>> being handled by one or several threads.
>> The whole working with Valentina. Every call (cursor) to Valentina in 
>> a
>> thread.
>> ( I am afraid that threads slows down too much the application)
>>
>> 3- A single application with four windows (one by screen), every 
>> window
>> being handled by timers (for example every 1/10th of second), what
>> allows to be much faster?
>
> All this on single computer?
>
> Then why you worry about speed?
>
> Only ONE process can be at front.
>
> Other process will sleep (in case you use threads or client/server)
>
> In fact 3-A is the worse solution -- because you will eat CPU time.
>
>
> -- 
> 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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