Re: sigx synchronous requests?

[Milosz Derezynski <internalerror gmail com>]

Thanks very much!

Regards
Milosz

On Wed, Apr 8, 2009 at 11:55 PM, klaus triendl <klaus triendl eu> wrote:

Milosz Derezynski schrieb:

Hey everyone, and especially Klaus,

I was wondering if there is a way to have synchronous (that is, achieved by proper internal locking) requests on sigx threadables?

I have the problem that currently I have a threadable class but I need one specific synchronous call that immediately returns and passes a direct
return value.

I can achieve this probably by doing some manual locking and so on, but I would prefer to do it with sigx directly if possible.

There is a way for synchronous requests: open_sync_tunnel() and open_sync_tunnel_with().

Since there's no direct way to express synchronous requests like sigx::request_f<> offers for async ones you have to write your own request wrapper function like so:

<code>
class mythread: public sigx::threadable
{
protected:
 // request handler
 int on_calc() { return 0; }

public:
 // request api
 int sync_calc();
};

int mythread::sync_calc()
{
 // sync request
 return sigx::open_sync_tunnel(
   sigc::mem_fun(this, &mythread::on_calc)
 );
}
</code>

I don't know exactly anymore why I didn't provide a sync_request_f<> wrapper, I guess the design rational was that it's not needed very often and that it's anyway better to use async requests.

Regards,
Klaus

-- 
Please note that according to the German law on data retention,
information on every electronic information exchange with me is
retained for a period of six months.
[Bitte beachten Sie, dass dem Gesetz zur Vorratsdatenspeicherung zufolge
jeder elektronische Kontakt mit mir sechs Monate lang gespeichert wird.]