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| author | ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-06-18 19:50:44 +0000 |
|---|---|---|
| committer | ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-06-18 19:50:44 +0000 |
| commit | 67d6aaca3521f6fe089103e72157e05ee950882a (patch) | |
| tree | 1b75a0e459d8935fc282d35f7c88edb79b94ff18 /variable.c | |
| parent | 81568a297b21334014c51fbde6c0026f1c6c86c3 (diff) | |
| download | ruby-67d6aaca3521f6fe089103e72157e05ee950882a.tar.gz | |
* variable.c (rb_const_set): fix WB miss.
WBs had located before creating reference between a klass
and constant value. It causes GC bug.
# pseudo code:
WB(klass, value); # WB and remember klass
st_insert(klass->const_table, const_id, value);
`st_insert()' can cause GC before inserting `value' and
forget `klass' from the remember set. After that, relationship
between `klass' and `value' are created with constant table.
Now, `value' can be young (shady) object and `klass' can be old
object, without remembering `klass' object.
At the next GC, old `klass' object will be skipped and
young (shady) `value' will be miss-collected. -> GC bug
Lesson: The place of a WB is important.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41396 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'variable.c')
| -rw-r--r-- | variable.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/variable.c b/variable.c index 79fcca0280..0dad3663a4 100644 --- a/variable.c +++ b/variable.c @@ -2155,7 +2155,7 @@ rb_const_set(VALUE klass, ID id, VALUE val) /* for autoloading thread, keep the defined value to autoloading storage */ if (load && (ele = check_autoload_data(load)) && (ele->thread == rb_thread_current())) { rb_vm_change_state(); - ele->value = val; + ele->value = val; /* autoload_i is shady */ return; } /* otherwise, allow to override */ @@ -2180,12 +2180,12 @@ rb_const_set(VALUE klass, ID id, VALUE val) rb_vm_change_state(); ce = ALLOC(rb_const_entry_t); + MEMZERO(ce, rb_const_entry_t, 1); ce->flag = visibility; - OBJ_WRITE(klass, (VALUE *)&ce->value, val); - OBJ_WRITE(klass, (VALUE *)&ce->file, rb_sourcefilename()); ce->line = rb_sourceline(); - st_insert(RCLASS_CONST_TBL(klass), (st_data_t)id, (st_data_t)ce); + OBJ_WRITE(klass, (VALUE *)&ce->value, val); + OBJ_WRITE(klass, (VALUE *)&ce->file, rb_sourcefilename()); } void |