[plt-scheme] Q. about editor<%> internal-locks

On Oct 7, 2009, at 5:06 PM, Matthew Flatt wrote:

> At Wed, 7 Oct 2009 16:56:05 -0400, Ryan Culpepper wrote:
>> On Oct 7, 2009, at 4:16 PM, Matthew Flatt wrote:
>>
>>> At Wed, 7 Oct 2009 12:58:31 -0700, John Clements wrote:
>>>> On Oct 7, 2009, at 12:31 PM, Robby Findler wrote:
>>>>
>>>>> Are you accessing the editor from more than one thread?
>>>>
>>>> No.  In particular, the only references to this editor are
>>>>
>>>> 1) it's embedded in a canvas which is part of a visible pane, and
>>>> 2) There's an "update" method that is called by only one thread.
>>>
>>> So the "one thread" in #2 is the same as the canvas's eventspace's
>>> handler thread?
>>
>> Does the canvas have its own eventspace, or does it use the frame's
>> eventspace?
>
> It's always the frame's eventspace.
>
>> What's the right way to modify the editor in a thread other than the
>> eventspace handler thread?
>
> Wrap the modifications with `begin-edit-sequence' and
> `end-edit-sequence'. An edit sequence takes a lock that is also used  
> by
> the repaint method of an editor.

Ah, I think most of my changes occur within an edit sequence, but some  
might not. That might account for the error showing up very rarely.

Thanks!

Ryan


>
>
> (I think that might be the answer for John, but only if he meant "Yes"
> instead of "No" in answering Robby's question.)
>