Re: [Chicken-users] Optional sqlite3 egg update

[Thomas Chust]

On Tue, 7 Mar 2006, JörgF. Wittenberger wrote:

> Am Dienstag, den 07.03.2006, 14:51 +0000 schrieb Thomas Chust:
> > On Tue, 7 Mar 2006, JörgF. Wittenberger wrote:
> ....
> > actually I must admit that I haven't used the SQLite3 egg for a real
> > multithreaded application so far. Nevertheless I have done some testing,
> > which suggests that everything works fine and the program stays responsive
> > under normal circumstances because the SQLite3 logic is indeed very fast
> > and in case a user defined function runs very long, the CHICKEN scheduler
> > does switch to other threads in the meantime.
>
> That's what I haven't been able to locate in the source code.  And that
> was what I wanted to learn how it could be done.

Hello,

the CHICKEN scheduler seems to be operational in Scheme callbacks 
automatically. I was positively surprised by that because I was already 
scratching my head about how to force some thread yielding mechanism into 
the callbacks.

> [...]
> > I definitely think that the scheme would be hard to implement for CHICKEN,
> > whose C API is not reentrant.
>
> There would have to be exactly one call, which other threads call call
> to signal the chicken thread about events.  I don't know whether chicken
> already has such a thing.  Do you?

I don't know about any such thing. But maybe one could get away with a 
status variable and a little hack in the CHICKEN scheduler to check that 
variable.

> [...]

cu,
Thomas