diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | hash.c | 35 |
2 files changed, 24 insertions, 18 deletions
@@ -1,5 +1,12 @@ 2010-01-26 Kaz Kylheku <kkylheku@gmail.com> + hash.c (hash_process_weak): There is no point in fixing up + the type codes of spuriously reached nodes; reached objects + will not be removed by weak processing and so it's better + to just detect those situations and short-circuit. + +2010-01-26 Kaz Kylheku <kkylheku@gmail.com> + Optimization in derivative-based regex engine. Exponential memory consumption behavior was observed when matching the input aaaaaa.... @@ -286,6 +286,13 @@ void hash_process_weak(void) cnum i; for (h = reachable_weak_hashes; h != 0; h = h->next) { + /* The table of a weak hash was spuriously reached by conservative GC; + it's a waste of time doing weak processing, since all keys and + values have been transitively marked as reachable; and so we + won't find anything to remove. */ + if (gc_is_reachable(h->table)) + continue; + switch (h->flags) { case hash_weak_none: /* what is this doing here */ @@ -298,12 +305,9 @@ void hash_process_weak(void) val *pchain = vecref_l(h->table, ind); val *iter; - for (iter = pchain; *iter != nil; ) { - val entry; - (*iter)->t.type &= ~REACHABLE; - entry = car(*iter); - entry->t.type &= ~REACHABLE; - if (!gc_is_reachable(car(entry))) + for (iter = pchain; !gc_is_reachable(*iter); ) { + val entry = car(*iter); + if (!gc_is_reachable(entry) && !gc_is_reachable(car(entry))) *iter = cdr(*iter); else iter = cdr_l(*iter); @@ -320,12 +324,9 @@ void hash_process_weak(void) val *pchain = vecref_l(h->table, ind); val *iter; - for (iter = pchain; *iter != nil; ) { - val entry; - (*iter)->t.type &= ~REACHABLE; - entry = car(*iter); - entry->t.type &= ~REACHABLE; - if (!gc_is_reachable(cdr(entry))) + for (iter = pchain; !gc_is_reachable(*iter); ) { + val entry = car(*iter); + if (!gc_is_reachable(entry) && !gc_is_reachable(car(entry))) *iter = cdr(*iter); else iter = cdr_l(*iter); @@ -342,12 +343,10 @@ void hash_process_weak(void) val *pchain = vecref_l(h->table, ind); val *iter; - for (iter = pchain; *iter != nil; ) { - val entry; - (*iter)->t.type &= ~REACHABLE; - entry = car(*iter); - entry->t.type &= ~REACHABLE; - if (!gc_is_reachable(car(entry)) || !gc_is_reachable(cdr(entry))) + for (iter = pchain; !gc_is_reachable(*iter); ) { + val entry = car(*iter); + if (!gc_is_reachable(entry) && + (!gc_is_reachable(car(entry)) || !gc_is_reachable(cdr(entry)))) *iter = cdr(*iter); else iter = cdr_l(*iter); |