Re: [Pharo-project] RoarVM - Pharo and Squeak on Multicore

Nov. 5, 2010


      On 5 November 2010 16:49, Stefan Marr <pharo@stefan-marr.de> wrote:
...
Hi:
On 03 Nov 2010, at 23:59, Stefan Marr wrote:
...
Probably our VM is behaving slightly different from what the SqueakVM. (Not sure what the 'right' thing to do is thought)
From my understanding, the idea is that if there is no event, the primitive will fail.
And all other images have that case covered. They set the first array index to EventTypeNone.
Thus, "InputEventFetcher>>primGetNextEvent: array" should look like:
primGetNextEvent: array
Â  Â  Â  "Store the next OS event available into the provided array.
Â  Â  Â  Essential."
Â  Â  Â  <primitive: 94>
Â  Â  Â  array at: 1 put: EventTypeNone. "STEFAN: Added this line"
Â  Â  Â  ^nil
However, since Pharo works on the other VM, I guess the primitive there is filling in the first slot of the array anyway.
So, what is the specification? I think the primitives have changed since 'the bluebook'.
Just to ask that question again: What is the conclusion, is the bug in the image or in the VM?
Here the Squeak implementation of it:

primGetNextEvent: array
	"Store the next OS event available into the provided array.
	Essential. If the VM is not event driven the ST code will fall
	back to the old-style mechanism and use the state based
	primitives instead."
	| kbd buttons modifiers pos mapped |
	<primitive: 94>
	"Simulate the events"
	array at: 1 put: EventTypeNone. "assume no more events"

	"First check for keyboard"
	kbd := super primKbdNext.
	kbd = nil ifFalse:[
		"simulate keyboard event"
		array at: 1 put: EventTypeKeyboard. "evt type"
		array at: 2 put: Time millisecondClockValue. "time stamp"
		array at: 3 put: (kbd bitAnd: 255). "char code"
		array at: 4 put: EventKeyChar. "key press/release"
		array at: 5 put: (kbd bitShift: -8). "modifier keys"
		^self].

	"Then check for mouse"
	buttons := super primMouseButtons.
	pos := super primMousePt.
	modifiers := buttons bitShift: -3.
	buttons := buttons bitAnd: 7.
	mapped := self mapButtons: buttons modifiers: modifiers.
	(pos = mousePosition and:[(mapped bitOr: (modifiers bitShift: 3)) =
mouseButtons])
		ifTrue:[^self].
	array
		at: 1 put: EventTypeMouse;
		at: 2 put: Time millisecondClockValue;
		at: 3 put: pos x;
		at: 4 put: pos y;
		at: 5 put: mapped;
		at: 6 put: modifiers.

so, i assume that problem is in Pharo , which does not handling a
primitive failure correctly (by setting
array at: 1 put: EventTypeNone. )
...
Thanks
Stefan
--
Stefan Marr
Software Languages Lab
Vrije Universiteit Brussel
Pleinlaan 2 / B-1050 Brussels / Belgium
http://soft.vub.ac.be/~smarr
Phone: +32 2 629 2974
Fax: Â  +32 2 629 3525
-- 
Best regards,
Igor Stasenko AKA sig.