Re: [Jack-Devel] [Fwd: Re: [Guitarix-developer] jack session crash]

Le 2 nov. 2011 à 20:33, Paul Davis a écrit :

> On Wed, Nov 2, 2011 at 3:14 PM, hermann <[hidden]> wrote:
> 
>> To make the mess complete, the weak linking doesn't work as
>> advertised by the jackd developers. At least my understanding and
>> that of the ubuntu / debian packagers seems to be:
>> 
>>  1) you can compile and link with either package (works)
>>  2) when the function is not in the shared library used at
>>     runtime, the function address will be 0. Does NOT work.
>> 
>> 2) only works when the shared lib used at runtime is the same as
>> the one used when linking. The compiler / linker will set the address
>> of a weak function that it does not find in the libraries supplied to
>> constant 0. Even when the funktion is in the library which is used at
>> runtime, there will be no runtime linking.
> 
> I have no idea what you are trying to say here.
> 
> If the function prototype was declared with weak linkage, and the
> symbol is not found at runtime, then this condition:
> 
>     if (function_name)
> 
> will evaluate to false.
> 
> ardour is doing this all the time.
> 
> its fairly clear from your test program that you have not include
> weakjack.h which is required to get weak linkage declarations.
> 
> --p

/**
 * get the assigned uuid for client.
 * safe to call from callback and all other threads.
 * memory needs to be freed.
 */

char *jack_client_get_uuid (jack_client_t *client) JACK_WEAK_EXPORT;


Freed by jak_free API yes ? ==> should be added in the doc 

/**
 * Get the session ID for a client name.
 * The session manager needs this to reassociate a client name to the session_id.
 */
char *jack_get_uuid_for_client_name (jack_client_t *client,
                                     const char    *client_name) JACK_WEAK_EXPORT;


Freed by jak_free API yes ? ==> should be added in the doc 

/**
 * Get the client name for a session_id.
 *
 * In order to snapshot the graph connections, the session manager needs to map
 * session_ids to client names.
 */
char *jack_get_client_name_by_uuid (jack_client_t *client,
                                    const char    *client_uuid ) JACK_WEAK_EXPORT;

Freed by jak_free API yes ? ==> should be added in the doc 



jack_client_get_uuid missing in JACK2:

code from JACK1:

char *
jack_client_get_uuid( jack_client_t *client )
{ 
	char retval[16];

	snprintf( retval, sizeof(retval), "%d", client->control->uid );

	return strdup(retval);
}

==> Torben, I guess JACK1  client->control->uid correspond to JACK2  fSessionID field in JackClientControl yes?

Thanks.

Stéphane 

1320263307.24160_0.ltw:2,a <3336F7B0-AEA6-4C08-A56F-C6CA884E7877 at grame dot fr>