diff options
| author | John Hawthorn <[email protected]> | 2025-03-18 15:02:44 -0700 |
|---|---|---|
| committer | John Hawthorn <[email protected]> | 2025-03-20 13:09:40 -0700 |
| commit | bfe6068417ca41a6b88a1ba5fcde04f9a76718a7 (patch) | |
| tree | be79cd8f9a3105f0eff1fb5f8d086e979e7de323 /vm_method.c | |
| parent | 62cc3464d902ee7a399ec8c38606fdc0ee98f05e (diff) | |
Use atomic for method reference count [Bug #20934]
This changes reference_count on rb_method_definition_struct into an
atomic.
Ractors can create additional references as part of `bind_call` or
(presumably) similar. Because this can be done inside Ractors, we should
use a lock or atomics so that we don't race and avoid incrementing.
Co-authored-by: wanabe <[email protected]>
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/12951
Diffstat (limited to 'vm_method.c')
| -rw-r--r-- | vm_method.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/vm_method.c b/vm_method.c index 205bf0b552..95a252337f 100644 --- a/vm_method.c +++ b/vm_method.c @@ -511,14 +511,13 @@ static void rb_method_definition_release(rb_method_definition_t *def) { if (def != NULL) { - const int reference_count = def->reference_count; - def->reference_count--; + const unsigned int reference_count_was = RUBY_ATOMIC_FETCH_SUB(def->reference_count, 1); - VM_ASSERT(reference_count >= 0); + RUBY_ASSERT_ALWAYS(reference_count_was != 0); - if (def->reference_count == 0) { - if (METHOD_DEBUG) fprintf(stderr, "-%p-%s:%d (remove)\n", (void *)def, - rb_id2name(def->original_id), def->reference_count); + if (reference_count_was == 1) { + if (METHOD_DEBUG) fprintf(stderr, "-%p-%s:1->0 (remove)\n", (void *)def, + rb_id2name(def->original_id)); if (def->type == VM_METHOD_TYPE_BMETHOD && def->body.bmethod.hooks) { xfree(def->body.bmethod.hooks); } @@ -526,7 +525,7 @@ rb_method_definition_release(rb_method_definition_t *def) } else { if (METHOD_DEBUG) fprintf(stderr, "-%p-%s:%d->%d (dec)\n", (void *)def, rb_id2name(def->original_id), - reference_count, def->reference_count); + reference_count_was, reference_count_was - 1); } } } @@ -614,9 +613,13 @@ setup_method_cfunc_struct(rb_method_cfunc_t *cfunc, VALUE (*func)(ANYARGS), int static rb_method_definition_t * method_definition_addref(rb_method_definition_t *def, bool complemented) { - if (!complemented && def->reference_count > 0) def->aliased = true; - def->reference_count++; - if (METHOD_DEBUG) fprintf(stderr, "+%p-%s:%d\n", (void *)def, rb_id2name(def->original_id), def->reference_count); + unsigned int reference_count_was = RUBY_ATOMIC_FETCH_ADD(def->reference_count, 1); + if (!complemented && reference_count_was > 0) { + /* TODO: A Ractor can reach this via UnboundMethod#bind */ + def->aliased = true; + } + if (METHOD_DEBUG) fprintf(stderr, "+%p-%s:%d->%d\n", (void *)def, rb_id2name(def->original_id), reference_count_was, reference_count_was+1); + return def; } |