We assert that the GC is not in a cycle in gc_start, but it does not show
what phase we're in if the assertion fails. This commit adds a debug
message for when the assertion fails.
Fixes [Bug #21201]
This change addresses a performance regression where defining methods
inside `refine` blocks caused severe slowdowns. The issue was due to
`rb_clear_all_refinement_method_cache()` triggering a full object
space scan via `rb_objspace_each_objects` to find and invalidate
affected callcaches, which is very inefficient.
To fix this, I introduce `vm->cc_refinement_table` to track
callcaches related to refinements. This allows us to invalidate
only the necessary callcaches without scanning the entire heap,
resulting in significant performance improvement.
Some GC implementations want to always know when an object is written to,
even if the written value is a special constant. Checking special constants
in rb_obj_written was a micro-optimization that made assumptions about
the GC implementation.
* Added `Ractor::Port`
* `Ractor::Port#receive` (support multi-threads)
* `Rcator::Port#close`
* `Ractor::Port#closed?`
* Added some methods
* `Ractor#join`
* `Ractor#value`
* `Ractor#monitor`
* `Ractor#unmonitor`
* Removed some methods
* `Ractor#take`
* `Ractor.yield`
* Change the spec
* `Racotr.select`
You can wait for multiple sequences of messages with `Ractor::Port`.
```ruby
ports = 3.times.map{ Ractor::Port.new }
ports.map.with_index do |port, ri|
Ractor.new port,ri do |port, ri|
3.times{|i| port << "r#{ri}-#{i}"}
end
end
p ports.each{|port| pp 3.times.map{port.receive}}
```
In this example, we use 3 ports, and 3 Ractors send messages to them respectively.
We can receive a series of messages from each port.
You can use `Ractor#value` to get the last value of a Ractor's block:
```ruby
result = Ractor.new do
heavy_task()
end.value
```
You can wait for the termination of a Ractor with `Ractor#join` like this:
```ruby
Ractor.new do
some_task()
end.join
```
`#value` and `#join` are similar to `Thread#value` and `Thread#join`.
To implement `#join`, `Ractor#monitor` (and `Ractor#unmonitor`) is introduced.
This commit changes `Ractor.select()` method.
It now only accepts ports or Ractors, and returns when a port receives a message or a Ractor terminates.
We removes `Ractor.yield` and `Ractor#take` because:
* `Ractor::Port` supports most of similar use cases in a simpler manner.
* Removing them significantly simplifies the code.
We also change the internal thread scheduler code (thread_pthread.c):
* During barrier synchronization, we keep the `ractor_sched` lock to avoid deadlocks.
This lock is released by `rb_ractor_sched_barrier_end()`
which is called at the end of operations that require the barrier.
* fix potential deadlock issues by checking interrupts just before setting UBF.
https://bugs.ruby-lang.org/issues/21262
Remove the unused constant HAS_MOVED_GFIELDSTBL and related methods.
In the mmtk/mmtk-ruby repo, we are now able to find the global field
(IV) table of a moved object during copying GC without using the
HAS_MOVED_GFIELDSTBL bit. We synchronize some of the code, although we
haven't implemented moving GC in ruby/mmtk, yet.
See: 13080acdf5https://github.com/ruby/mmtk/commit/400ba4e747
This makes `RBobject` `4B` larger on 32 bit systems
but simplifies the implementation a lot.
[Feature #21353]
Co-authored-by: Jean Boussier <byroot@ruby-lang.org>
We should get the object ID for finalizers in rb_gc_impl_define_finalizer
instead of when we create the finalizer job in make_final_job because
when we are in multi-Ractor mode, object ID needs to walk the references
which allocates an identity hash table. We cannot allocate in make_final_job
because it is in a MMTk worker thread.
https://github.com/ruby/mmtk/commit/922f22a690
The previous implementation assumed `RBasic` size is `2 * sizeof(VALUE)`,
might as well not make assumption and use a proper `sizeof`.
Co-Authored-By: John Hawthorn <john@hawthorn.email>
This commit allows building YJIT and ZJIT simultaneously, a "combo
build". Previously, `./configure --enable-yjit --enable-zjit` failed. At
runtime, though, only one of the two can be enabled at a time.
Add a root Cargo workspace that contains both the yjit and zjit crate.
The common Rust build integration mechanisms are factored out into
defs/jit.mk.
Combo YJIT+ZJIT dev builds are supported; if either JIT uses
`--enable-*=dev`, both of them are built in dev mode.
The combo build requires Cargo, but building one JIT at a time with only
rustc in release build remains supported.
After fork we reset to single ractor mode (which IMO we shouldn't do,
but it requires more work to fix) and so we need to add the pending
object counts back to the main heap.
And get rid of the `obj_to_id_tbl`
It's no longer needed, the `object_id` is now stored inline
in the object alongside instance variables.
We still need the inverse table in case `_id2ref` is invoked, but
we lazily build it by walking the heap if that happens.
The `object_id` concern is also no longer a GC implementation
concern, but a generic implementation.
Co-Authored-By: Matt Valentine-House <matt@eightbitraptor.com>
Ivars will longer be the only thing stored inline
via shapes, so keeping the `iv_index` and `ivptr` names
would be confusing.
Instance variables won't be the only thing stored inline
via shapes, so keeping the `ivptr` name would be confusing.
`field` encompass anything that can be stored in a VALUE array.
Similarly, `gen_ivtbl` becomes `gen_fields_tbl`.
Currently the count of allocated object for a heap is incremented
without regards to parallelism which leads to incorrect counts.
By maintaining a local counter in the ractor newobj cache, and only
syncing atomically with some granularity, we can improve the correctness
without increasing contention.
The allocated object count is also synced when the ractor is freed.
Co-authored-by: Jean Boussier <jean.boussier@gmail.com>
In cb1ea54bbf6cdf49c53f42720fec1a151069810c I added one more
metadata flag, but didn't notice `RB_GC_OBJECT_METADATA_ENTRY_COUNT`
had to be incremented.
This should fix ASAN builds.
Interestingly, bdb25959fb047af0358f33d7327b7752dca14aa4 already
caused the count to be off by one, so I had to increment it by
2.
Given that the currently planned ractor local GC implementation
performance will heavilly be influenced by the number of shareable
objects it would be valuable to be able to know how many of them
are in the heap.
`objspace->finalizer_table` must be synchronized,
otherwise concurrent insertion from multiple ractors
will cause a crash.
Repro:
```ruby
ractors = 5.times.map do |i|
Ractor.new do
100_000.times.map do
o = Object.new
ObjectSpace.define_finalizer(o, ->(id) {})
o
end
end
end
ractors.each(&:take)
```
This inverse table is only useful if `ObjectSpace._id2ref` is used,
which is extremely rare. The only notable exception is the `drb` gem
and even then it has an option not to rely on `_id2ref`.
So if we assume this table will never be looked up, we can just
not maintain it, and if it turns out `_id2ref` is called, we
can lock the VM and re-build it.
```
compare-ruby: ruby 3.5.0dev (2025-04-10T09:44:40Z master 684cfa42d7) +YJIT +PRISM [arm64-darwin24]
built-ruby: ruby 3.5.0dev (2025-04-10T10:13:43Z lazy-id-to-obj d3aa9626cc) +YJIT +PRISM [arm64-darwin24]
warming up..
| |compare-ruby|built-ruby|
|:----------|-----------:|---------:|
|baseline | 26.364M| 25.974M|
| | 1.01x| -|
|object_id | 10.293M| 14.202M|
| | -| 1.38x|
```
[Bug #21214]
If we allocate objects where one heap holds transient objects and another
holds long lived objects, then the heap with transient objects will grow
along the heap with long lived objects, causing higher memory usage.
For example, we can see this issue in this script:
def allocate_small_object = []
def allocate_large_object = Array.new(10)
arys = Array.new(1_000_000) do
# Allocate 10 small transient objects
10.times { allocate_small_object }
# Allocate 1 large object that is persistent
allocate_large_object
end
pp GC.stat
pp GC.stat_heap
Before this change:
heap_live_slots: 2837243
{0 =>
{slot_size: 40,
heap_eden_pages: 1123,
heap_eden_slots: 1838807},
2 =>
{slot_size: 160,
heap_eden_pages: 2449,
heap_eden_slots: 1001149},
}
After this change:
heap_live_slots: 1094474
{0 =>
{slot_size: 40,
heap_eden_pages: 58,
heap_eden_slots: 94973},
2 =>
{slot_size: 160,
heap_eden_pages: 2449,
heap_eden_slots: 1001149},
}
