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authorKaz Kylheku <kaz@kylheku.com>2014-10-22 20:48:45 -0700
committerKaz Kylheku <kaz@kylheku.com>2014-10-22 20:48:45 -0700
commit2fbc83085f4a73b228c4441294e66485c319639a (patch)
tree11ea46eb4fcda7515a198d46c136fe735aaa04a8 /gc.h
parentfbcb476d1d4cc015fa6afbf9135f5b92c1c1e299 (diff)
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Ensure that a hash reorganization doesn't take place
during a traversal, which could cause items to be visited twice or skipped. * gc.c (full_gc): Changed from static to exter (full_gc): Changed to internal linkage. * gc.h (full_gc): Declared. * hash.c (struct hash): New member, usecount. (struct hash_iter): New member, next. (reachable_iters): New static variable. (hash_mark): Reset the usecount of every reachable hash table. (hash_iter_mark): Add every reachable iterator to reachable_iters list. (make_hash, make_similar_hash, copy_hash): Initialize usecount. (gethash_c): Do not call hash_grow if usecount is nonzero. (hash_begin): Initialize next field of hash_iter to null. Increment use count on hash table. (hash_next): When traversal ends, release use count, and null out the hash table reference. (do_weak_tables): New static function. (do_iters): New static function. (hash_process_weak): Weak hash processing logic moved to do_weak_tables. Also calls do_iters. * txr.1: Describe hash table traversal, and the assurances and caveats about inserting and deleting items.
Diffstat (limited to 'gc.h')
-rw-r--r--gc.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/gc.h b/gc.h
index 51452243..c00d857b 100644
--- a/gc.h
+++ b/gc.h
@@ -39,6 +39,7 @@ int gc_is_reachable(val);
val gc_set(loc, val);
val gc_push(val, loc);
val gc_mutated(val);
+extern int full_gc;
#endif
void unmark(void);