Startup Code (from Icon ) - Forbid function

Asman · 03 January 2014, 23:07

As I understand correctly Forbid function is used to off multitasking and I should use pair Forbid and Permit function. But I don't understand why in startup code from icon there is the Forbid call before back to OS. Mean

Code:

	...
	jsr	Forbid(A6)
	move.l	WBenchMsg(PC),A1	;WBenchMsg from GetMsg
	jsr	ReplyMsg(A6)
	moveq	#0,D0
	rts

I found only following information in comment in startup.asm:

"; we forbid so workbench can't UnLoadSeg() us before we are done"

But what about Permit ? Is there any detailed information about icon startup ?

Leffmann · 04 January 2014, 04:23

Replying to the Workbench startup-message is how you tell Workbench that your program is about to end, but there's always the chance that a task-switch occurs between the call to ReplyMsg() and actually ending your program, so you need to disable multi-tasking to prevent this. It's not necessary to call Permit() again because this state is relative to each task, so multi-tasking will be correctly enabled again when your program ends.

The details are in the RKMs of course, and probably in the NKDs as well.

Asman · 04 January 2014, 10:45

Thanks a lot.

03 January 2014, 23:07	#1
Asman 68k Join Date: Sep 2005 Location: Somewhere Posts: 828	Startup Code (from Icon ) - Forbid function As I understand correctly Forbid function is used to off multitasking and I should use pair Forbid and Permit function. But I don't understand why in startup code from icon there is the Forbid call before back to OS. Mean Code: ... jsr Forbid(A6) move.l WBenchMsg(PC),A1 ;WBenchMsg from GetMsg jsr ReplyMsg(A6) moveq #0,D0 rts I found only following information in comment in startup.asm: "; we forbid so workbench can't UnLoadSeg() us before we are done" But what about Permit ? Is there any detailed information about icon startup ?

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04 January 2014, 04:23	#2
Leffmann Join Date: Jul 2008 Location: Sweden Posts: 2,269	Replying to the Workbench startup-message is how you tell Workbench that your program is about to end, but there's always the chance that a task-switch occurs between the call to ReplyMsg() and actually ending your program, so you need to disable multi-tasking to prevent this. It's not necessary to call Permit() again because this state is relative to each task, so multi-tasking will be correctly enabled again when your program ends. The details are in the RKMs of course, and probably in the NKDs as well.

04 January 2014, 10:45	#3
Asman 68k Join Date: Sep 2005 Location: Somewhere Posts: 828	Thanks a lot.

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