Re: Minutes 20070516

[Mark Wielaard <mark@klomp.org>]

[-- Attachment #1: Type: text/plain, Size: 2052 bytes --]

Hi elena,

Thanks again for making the meeting minutes. Much appreciated.

On Wed, 2007-05-16 at 10:07 -0400, Elena Zannoni wrote:
> thread specific breakpoints? Not yet. But the mechanism is in place
> already to detect if a thread must ignore a breakpoint or not.  Right
> now: Breakpoint is hit->all tasks get notified. BP set globally in
> process space. Notify the listener, and it decides if the task is the
> one that we are interested in. There seems to have been an interface
> change at some point, can this be discussed on list? It's not clear
> what has changed. (Mark?) Bind bp to process or to task? 

I don't believe anything changed here since it was implemented. Which
doesn't mean it cannot/shouldn't be improved (now that it is implemented
I see why you want to have it setup differently, isn't that always the
case...). Here is how it currently works:

- Given a Task you call requestAddCodeObserver(TaskObserver.Code, long)
where the address is given as a long and the Code observer is the
listener that you want to be called whenever the Task hits the given
address.
- This inserts a breakpoint at the given address in the Proc associated
with the Task (the breakpoint is global since the address space is
shared between Tasks).
- Whenever the breakpoint is hit in the process by a Task that task is
temporarily suspended and frysk-core is notified about the event.
- frysk-core calls the given Code observer is called with updateHit
(Task, long) indicating the Task that tripped over the breakpoint at a
given address. Returning Action.BLOCK from that method will permanently
block that Task, returning Action.CONTINUE the Task will be resumed
(given that no other listener returned BLOCK).

> HPD has thread sets/ actionpoints (signals, etc...)

Totalview also has a task groups idea. Maybe that is also interesting to
look at as inspiration on how to define thread/task/process sets:
http://www.totalviewtech.com/Documentation/latest/html/User_Guide/CreatingGroups.html

Cheers,

Mark

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]