suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

futures: bug fix

Browse Source 
The problem was in the handing of "lightweight continuations" used to
represent suspended computations, and in particular the handling
of continuation marks (such as the ones added by DrRacket's debugging
mode).

Unfortunately, I wasn't able to construct a simpler test case that
triggers the problem. I think the number of installed continuation marks
has to be just right, and there have to be some replacing marks, and
a lightweight continuaiton has to be captured at the right time
as a result of applying a previously captured continuation.

Closes PR 13427

Merge to v5.3.2
(cherry picked from commit f93c620814)
This commit is contained in:
Matthew Flatt 2013-01-11 12:30:36 -07:00 committed by Ryan Culpepper
parent 1de0465687
commit 478f3d64d9
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/racket/src/fun.c
View File

@ -8522,7 +8522,6 @@ Scheme_Lightweight_Continuation *scheme_restore_lightweight_continuation_marks(S
cm_len = lw->saved_lwc->cont_mark_stack_end - lw->saved_lwc->cont_mark_stack_start;
cm_pos_delta = MZ_CONT_MARK_POS + 2 - lw->saved_lwc->cont_mark_pos_start;
MZ_CONT_MARK_POS = lw->saved_lwc->cont_mark_pos_end + cm_pos_delta;
if (cm_len) {
/* install captured continuation marks, adjusting the pos
@ -8540,6 +8539,8 @@ Scheme_Lightweight_Continuation *scheme_restore_lightweight_continuation_marks(S
}
}
MZ_CONT_MARK_POS = lw->saved_lwc->cont_mark_pos_end + cm_pos_delta;
return lw;
}