The `p->field = rb_gc_location(p->field)` isn't ideal because it means all
references are rewritten on compaction, regardless of whether the referenced
object has moved. This isn't good for caches nor for Copy-on-Write.
`rb_gc_mark_and_move` avoid needless writes, and most of the time allow to
have a single function for both marking and updating references.
Symbol last_id was changed to next_id, but it remained to be set to
tNEXT_ID - 1 initially, causing the initial static symbol to overlap with
the last built-in symbol in id.def.
If we create a key but don't insert it (due to other Ractor winning the
race), then it would leak memory if we don't free it. This introduces a
new function to free that memory for this case.
We don't need to delay the freeing of the fstr for the symbol if we store
the hash of the fstr in the dynamic symbol and we use compare-by-identity
for removing the dynamic symbol from the sym_set.
GCC 13.3.0 (Ubuntu 24.04) emits the following warning:
../symbol.c: In function ‘rb_id_attrset’:
../symbol.c:175:9: warning: ‘nonstring’ attribute ignored on objects of type ‘const char[][8]’ [-Wattributes]
175 | RBIMPL_ATTR_NONSTRING() static const char id_types[][8] = {
| ^~~~~~~~~~~~~~~~~~~~~
The `ids` array and `dsymbol_fstr_hash` were pinned because they were
kept alive by rb_vm_register_global_object. This prevented the GC from
moving them even though there were reference updating code.
This commit changes it to be marked movable by marking it as a root object.
This `st_table` is used to both mark and pin classes
defined from the C API. But `vm->mark_object_ary` already
does both much more efficiently.
Currently a Ruby process starts with 252 rooted classes,
which uses `7224B` in an `st_table` or `2016B` in an `RArray`.
So a baseline of 5kB saved, but since `mark_object_ary` is
preallocated with `1024` slots but only use `405` of them,
it's a net `7kB` save.
`vm->mark_object_ary` is also being refactored.
Prior to this changes, `mark_object_ary` was a regular `RArray`, but
since this allows for references to be moved, it was marked a second
time from `rb_vm_mark()` to pin these objects.
This has the detrimental effect of marking these references on every
minors even though it's a mostly append only list.
But using a custom TypedData we can save from having to mark
all the references on minor GC runs.
Addtionally, immediate values are now ignored and not appended
to `vm->mark_object_ary` as it's just wasted space.
Previously, our compile time check rejected dynamic symbols (e.g. what
String#to_sym could return) even though we could handle them just fine.
The runtime guards for the type of method name was also overly
restrictive and didn't accept dynamic symbols.
Fold the type check into the rb_get_symbol_id() and take advantage of
the guard already checking for 0. This also avoids generating the same
call twice in case the same method name is presented as different
types.
[Bug #20245]
We sometimes pass in a fake string to sym_check_asciionly. This can crash
if sym_check_asciionly raises because it creates a CFP with the fake
string as the receiver which will crash if GC tries to mark the CFP.
For example, the following script crashes:
GC.stress = true
Object.const_defined?("\xC3")
when the RUBY_FREE_ON_SHUTDOWN environment variable is set, manually free memory at shutdown.
Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
Co-authored-by: Peter Zhu <peter@peterzhu.ca>
* Implement optimize send in yjit
This successfully makes all our benchmarks exit way less for optimize send reasons.
It makes some benchmarks faster, but not by as much as I'd like. I think this implementation
works, but there are definitely more optimial arrangements. For example, what if we compiled
send to a jump table? That seems like perhaps the most optimal we could do, but not obvious (to me)
how to implement give our current setup.
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
* Attempt at fixing the issues raised by @XrXr
* fix allowlist
* returns 0 instead of nil when not found
* remove comment about encoding exception
* Fix up c changes
* Update assert
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
* get rid of unneeded code and fix the flags
* Apply suggestions from code review
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
* rename and fix typo
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
rb_ary_tmp_new suggests that the array is temporary in some way, but
that's not true, it just creates an array that's hidden and not on the
transient heap. This commit renames it to rb_ary_hidden_new.
Prior to this commit it was possible to call `ObjectSpace._id2ref` with
an offset static symbol object_id and get back a new, incorrectly tagged
symbol:
```
> sensible_sym = ObjectSpace._id2ref(:a.object_id)
=> :a
> nonsense_sym = ObjectSpace._id2ref(:a.object_id + 40)
=> :a
> sensible_sym == nonsense_sym
=> false
```
`nonsense_sym` ends up tagged with `RUBY_ID_INSTANCE` instead of
`RB_ID_LOCAL`. That means we can do silly things like:
```
> foo = Object.new
> foo.instance_variable_set(:a, 123)
(irb):2:in `instance_variable_set': `a' is not allowed as an instance variable name (NameError)
> foo.instance_variable_set(ObjectSpace._id2ref(:a.object_id + 40), 123)
=> 123
> foo.instance_variables
=> [:a]
```
This was happening because `get_id_entry` ignores the tag bits when
looking up the symbol. So `rb_id2str(symid)` would return a value and
then we'd continue on with the nonsense `symid`.
This commit prevents the situation by checking that the `symid` actually
matches what we get back from `get_id_entry`. Now we get a `RangeError`
for the nonsense id:
```
> ObjectSpace._id2ref(:a.object_id)
=> :a
> ObjectSpace._id2ref(:a.object_id + 40)
(irb):1:in `_id2ref': 0x000000000013f408 is not symbol id value (RangeError)
```
Co-authored-by: John Hawthorn <jhawthorn@github.com>
Dumped iseq binary can not have unnamed symbols/IDs, and ID 0 is
stored instead. As `struct rb_id_table` disallows ID 0, also for
the distinction, re-assign a new temporary ID based on the local
variable table index when loading from the binary, as well as the
parser.
```ruby
def foo(*); ->{ super }; end
```
This code makes anonymous parameters which is not registered as an
ID. The problem is that when Ractors try to scan `getlocal`
instructions, it puts the Symbol corresponding to the parameter
in to a hash. Since it is not registered, we end up with a
strange exception. This commit wraps the unregistered ID in an
internal ID so that we get the same exception for `...` as `*`.
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Co-Authored-By: John Hawthorn <john@hawthorn.email>
