diff options
| author | fche <fche> | 2005-11-08 18:43:37 +0000 |
|---|---|---|
| committer | fche <fche> | 2005-11-08 18:43:37 +0000 |
| commit | 1a0e4851043eb5679543c7779b00e3d925e83004 (patch) | |
| tree | 4b4f9bd1fdfe271c8a0d20884331df94ea6bfe50 | |
| parent | 28776e58055246efc0083d05648eaf2e97b04644 (diff) | |
| download | systemtap-steved-1a0e4851043eb5679543c7779b00e3d925e83004.tar.gz systemtap-steved-1a0e4851043eb5679543c7779b00e3d925e83004.tar.xz systemtap-steved-1a0e4851043eb5679543c7779b00e3d925e83004.zip | |
2005-11-08 Frank Ch. Eigler <fche@redhat.com>
* translate.cxx (c_unparser::visit_foreach_loop): With PR 1275
done, add back read lock around foreach loop. Add a write lock
around preceding sort operation. Leave a race condition window. :-(
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | translate.cxx | 19 |
2 files changed, 17 insertions, 8 deletions
@@ -1,5 +1,11 @@ 2005-11-08 Frank Ch. Eigler <fche@redhat.com> + * translate.cxx (c_unparser::visit_foreach_loop): With PR 1275 + done, add back read lock around foreach loop. Add a write lock + around preceding sort operation. Leave a race condition window. :-( + +2005-11-08 Frank Ch. Eigler <fche@redhat.com> + * translate.cxx (mapvar::exists): Correct some more. 2005-11-08 Frank Ch. Eigler <fche@redhat.com> diff --git a/translate.cxx b/translate.cxx index 95a37438..799cf8d8 100644 --- a/translate.cxx +++ b/translate.cxx @@ -1648,18 +1648,21 @@ c_unparser::visit_foreach_loop (foreach_loop *s) // initialization - // XXX: until bug #1275 is fixed, any reference into a foreach()-iterated - // array is an instant deadlock. For now, don't lock around foreach(), - // and hope that no concurrent probe handler will modify this array. - // - // varlock_r guard (*this, mv); - // sort array if desired if (s->sort_direction) - o->newline() << "_stp_map_sort (" << mv.qname() << ", " - << s->sort_column << ", " << - s->sort_direction << ");"; + { + varlock_w sort_guard (*this, mv); + o->newline() << "_stp_map_sort (" << mv.qname() << ", " + << s->sort_column << ", " << - s->sort_direction << ");"; + } // NB: sort direction sense is opposite in runtime, thus the negation + // XXX: There is a race condition here. Since we can't convert a + // write lock to a read lock, it is possible that another sort or update + // may get sandwiched between the release of sort_guard and the + // acquisition of guard. + + varlock_r guard (*this, mv); o->newline() << iv << " = " << iv.start (mv) << ";"; // condition |