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

Le 2 nov. 2011 à 21:09, hermann a écrit :

> Am Mittwoch, den 02.11.2011, 20:48 +0100 schrieb Stéphane Letz:
>> 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 
> 
> Stéphane, is there any chance that this comes in sync for both jack
> versions ?
> 
> greets
> hermann
> 

I'm on JACK2, not JACK1... I can add jack_client_get_uuid.

Stéphane

1320267170.30425_0.ltw:2,a <A54C4B6C-682A-476C-9E24-ED12950BC708 at grame dot fr>