[REBOL] Re: Multiple Threads Crash
From: holger:rebol at: 24-Jul-2001 9:40
On Mon, Jul 23, 2001 at 07:01:00PM -0400, [Sanghabum--aol--com] wrote:
> Hi all,
> The code below is something I started writing to get a feel for Rebol's
> undocumented concurrent and muti-threading capabilities, and to verify where
> and what sort of serialisation code I need to build into my applications.
Calling 'wait from within an awake handler is not really supported. It is
bad style anyway, because in event-driven systems event handlers are not
allowed to block. That's because blocking in an event handler makes programs
extremely difficult to debug, in particular if the list of handlers (meaning,
faces) is modified while another handler is suspended. The problem is that
all those suspended handlers carry hidden "context" around with them, and
you might end up with an "old" handler being woken up from suspension after
the face it has been associated with has already been removed from the
pane, by a different handler. Other complications are possible, as well. It
is extremely difficult to foresee all of these side effects, so programs that
use tricks like that are bound to be buggy and full of race conditions.
As for the crashes, this is the result of a limit on recursion in current REBOL
versions. Should be eliminated in one of the next version.