🚀 go-pugleaf

In article <2845@harrier.ukc.ac.uk> mtp@ukc.ac.uk (M.T.Paley) writes:
>Hello,
>	Has anyone ever managed to send a message to a desk accessory in GEM?
>It always bombs out whenever I send a message to any but the process that is
>sending the message ( the ap_id returned by appl_open() ).
>
>   E.G.
>		:
>	ap_wid = appl_find("MYACC   ");			/* This bit works */
>	gets(message);					/* Unimportant */
>	appl_write(ap_wid,strlen(message),message);	/* This crashes */
>		:
>
>However if appl_find is given the name of the current process then this
>code works fine.
>
>It is not the desk accessory that is at fault as it works perfectly with system
>messages sent by the AES.
>
>Anyone tried anything similar at any time?
>
>				Matthew
>
>Janet: mtp@uk.ac.ukc
>       phg445@uk.ac.ukc.saturn@uk.ac.ukc

O.K. I have both an answer and a question :
	(hence the posting - 	I hope the info will be of use to some,
				I hope that someone can answer my query.

The following code I wrote appears to work as expected :

	It wakes up a desk accessory by sending it an AC_OPEN message.
Note :
	first it uses appl_find to get the handle,
	then writes a 16 Byte   message to it;
	for the accessory to actually get a chance to do anything
		appl_yield must be called (Tos 1.4),
		or event_timer with a delay of zero 
		- note 32 bits :  event_timer(0) will crash. (I know !)

	The format of the message depends on the message, but if the 
	standard event_multi is to process it should contain
	between 6 and 16 Bytes : i.e. the first 3 ints must be present.
	If it is longer, then appl_read must be used to process it.

My question concerns th 4th int in Mssg  (a 1) : for AC_OPEN, this should be
"the number of the accessory (on the menu bar)" - how do I establish this ?
Is it the same as the acc_handle (also a 1) ? (An accessory only realy needs
to check this if it is installing more than one entry on the menu bar.)

WORKS :   (excuse mixed ints, Bytes)

wake_acc()

{
int acc_handle, res ;
int Mssg[8] = { AC_OPEN, handle, 0, 1, 0,0,0,0 } ;
	acc_handle = appl_find("ANACLOCK");
	res = appl_write(acc_handle, 16, Mssg );
	evnt_timer(0,0);
 
}

Hope this helps people (if I have erred, please say - I have read what I
can, but the sheer surprise when something like this works ....)

cheers
 	beau webber	 jbww.@ukc.ac.uk

P.S.
	why is it one knows more of what is happening at the other end of the
	world, than at the other end of the building ?