* Copy cvar table on clone
When a class with a class variable is cloned we need to also copy the
cvar cache table from the original table to the clone. I found this bug
while working on fixing [Bug #19379]. While this does not fix that bug
directly it is still a required change to fix another bug revealed by
the fix in https://github.com/ruby/ruby/pull/7265
This needs to be backported to 3.2.x and 3.1.x.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
* Fix cvar caching when class is cloned
The class variable cache that was added in
https://github.com/ruby/ruby/pull/4544 changed the behavior of class
variables on cloned classes. As reported when a class is cloned AND a
class variable was set, and the class variable was read from the
original class, reading a class variable from the cloned class would
return the value from the original class.
This was happening because the IC (inline cache) is stored on the ISEQ
which is shared between the original and cloned class, therefore they
share the cache too.
To fix this we are now storing the `cref` in the cache so that we can
check if it's equal to the current `cref`. If it's different we don't
want to read from the cache. If it's the same we do. Cloned classes
don't share the same cref with their original class.
This will need to be backported to 3.1 in addition to 3.2 since the bug
exists in both versions.
We also added a marking function which was missing.
Fixes [Bug #19379]
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
* Add missing write barrier
We were missing the write barrier for class_value to cref. This should
fix the segv we were seeing in http://ci.rvm.jp/logfiles/brlog.trunk-gc-asserts.20230601-165052
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
---------
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
[Bug #18627] Fix crash when including module
During lazy sweeping, the iclass could be a dead object that has not yet
been swept. However, the chain of superclasses of the iclass could
already have been swept (and become a new object), which would cause a
crash when trying to read the object.
---
class.c | 48 ++++++++++++++++++++++++++++++------------------
1 file changed, 30 insertions(+), 18 deletions(-)
Allow include before calling Module#initialize
This is to allow Module subclasses that include modules before
calling super in the subclass's initialize.
Remove rb_module_check_initializable from Module#initialize.
Module#initialize only calls module_exec if a block is passed,
it doesn't have other issues that would cause problems if
called multiple times or with an already initialized module.
Move initialization of super to Module#allocate, though I'm not
sure it is required there. However, it's needed to be removed
from Module#initialize for this to work.
Fixes [Bug #18292]
---
class.c | 1 +
object.c | 1 -
test/ruby/test_module.rb | 10 ++++++++++
3 files changed, 11 insertions(+), 1 deletion(-)
This commit adds a Ractor cache for every size pool. Previously, all VWA
allocated objects used the slowpath and locked the VM.
On a micro-benchmark that benchmarks String allocation:
VWA turned off:
29.196591 0.889709 30.086300 ( 9.434059)
VWA before this commit:
29.279486 41.477869 70.757355 ( 12.527379)
VWA after this commit:
16.782903 0.557117 17.340020 ( 4.255603)
Updating RCLASS_PARENT_SUBCLASSES and RCLASS_MODULE_SUBCLASSES while
compacting can trigger the read barrier. This commit makes
RCLASS_SUBCLASSES a doubly linked list with a dedicated head object so
that we can add and remove entries from the list without having to touch
an object in the Ruby heap
With RVARGC we always store the rb_classext_t in the same slot as the
RClass struct that refers to it. So we don't need to store the pointer
or access through the pointer anymore and can switch the RCLASS_EXT
macro to use an offset
Follow up of 428227472f. The previous fix
uses `rb_ary_new_from_values` to create the result array, but it may
trigger the GC.
This second try is to create the result array by `rb_ary_new_capa`
before the second iteration, and assume that `rb_ary_push` does not
trigger GC. This assumption is very fragile, so should be improved in
future.
[Bug #18282] [Feature #14394]
GC must not be triggered during callback of rb_class_foreach_subclass.
To prevent GC, we can not use rb_ary_push. Instead, this changeset calls
rb_class_foreach_subclass twice: first counts the subclasses, then
allocates a buffer (which may cause GC and reduce subclasses, but not
increase), and finally stores the subclasses to the buffer.
[Bug #18282] [Feature #14394]
Refinement#import_methods imports methods from modules.
Unlike Module#include, it copies methods and adds them into the refinement,
so the refinement is activated in the imported methods.
[Bug #17429] [ruby-core:101639]
Must not be a bad idea to improve documents. [ci skip]
In fact many functions declared in the header file are already
documented more or less. They were just copy & pasted, with applying
some style updates.
Must not be a bad idea to improve documents. [ci skip]
In fact many functions declared in the header file are already
documented more or less. They were just copy & pasted, with applying
some style updates.
This commits implements size classes in the GC for the Variable Width
Allocation feature. Unless `USE_RVARGC` compile flag is set, only a
single size class is created, maintaining current behaviour. See the
redmine ticket for more details.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
This commits implements size classes in the GC for the Variable Width
Allocation feature. Unless `USE_RVARGC` compile flag is set, only a
single size class is created, maintaining current behaviour. See the
redmine ticket for more details.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
Redo of 34a2acdac7 and
931138b006 which were reverted.
GitHub PR #4340.
This change implements a cache for class variables. Previously there was
no cache for cvars. Cvar access is slow due to needing to travel all the
way up th ancestor tree before returning the cvar value. The deeper the
ancestor tree the slower cvar access will be.
The benefits of the cache are more visible with a higher number of
included modules due to the way Ruby looks up class variables. The
benchmark here includes 26 modules and shows with the cache, this branch
is 6.5x faster when accessing class variables.
```
compare-ruby: ruby 3.1.0dev (2021-03-15T06:22:34Z master 9e5105c) [x86_64-darwin19]
built-ruby: ruby 3.1.0dev (2021-03-15T12:12:44Z add-cache-for-clas.. c6be009) [x86_64-darwin19]
| |compare-ruby|built-ruby|
|:--------|-----------:|---------:|
|vm_cvar | 5.681M| 36.980M|
| | -| 6.51x|
```
Benchmark.ips calling `ActiveRecord::Base.logger` from within a Rails
application. ActiveRecord::Base.logger has 71 ancestors. The more
ancestors a tree has, the more clear the speed increase. IE if Base had
only one ancestor we'd see no improvement. This benchmark is run on a
vanilla Rails application.
Benchmark code:
```ruby
require "benchmark/ips"
require_relative "config/environment"
Benchmark.ips do |x|
x.report "logger" do
ActiveRecord::Base.logger
end
end
```
Ruby 3.0 master / Rails 6.1:
```
Warming up --------------------------------------
logger 155.251k i/100ms
Calculating -------------------------------------
```
Ruby 3.0 with cvar cache / Rails 6.1:
```
Warming up --------------------------------------
logger 1.546M i/100ms
Calculating -------------------------------------
logger 14.857M (± 4.8%) i/s - 74.198M in 5.006202s
```
Lastly we ran a benchmark to demonstate the difference between master
and our cache when the number of modules increases. This benchmark
measures 1 ancestor, 30 ancestors, and 100 ancestors.
Ruby 3.0 master:
```
Warming up --------------------------------------
1 module 1.231M i/100ms
30 modules 432.020k i/100ms
100 modules 145.399k i/100ms
Calculating -------------------------------------
1 module 12.210M (± 2.1%) i/s - 61.553M in 5.043400s
30 modules 4.354M (± 2.7%) i/s - 22.033M in 5.063839s
100 modules 1.434M (± 2.9%) i/s - 7.270M in 5.072531s
Comparison:
1 module: 12209958.3 i/s
30 modules: 4354217.8 i/s - 2.80x (± 0.00) slower
100 modules: 1434447.3 i/s - 8.51x (± 0.00) slower
```
Ruby 3.0 with cvar cache:
```
Warming up --------------------------------------
1 module 1.641M i/100ms
30 modules 1.655M i/100ms
100 modules 1.620M i/100ms
Calculating -------------------------------------
1 module 16.279M (± 3.8%) i/s - 82.038M in 5.046923s
30 modules 15.891M (± 3.9%) i/s - 79.459M in 5.007958s
100 modules 16.087M (± 3.6%) i/s - 81.005M in 5.041931s
Comparison:
1 module: 16279458.0 i/s
100 modules: 16087484.6 i/s - same-ish: difference falls within error
30 modules: 15891406.2 i/s - same-ish: difference falls within error
```
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
Instead of on read. Once it's in the inline cache we never have to make
one again. We want to eventually put the value into the cache, and the
best opportunity to do that is when you write the value.
This change implements a cache for class variables. Previously there was
no cache for cvars. Cvar access is slow due to needing to travel all the
way up th ancestor tree before returning the cvar value. The deeper the
ancestor tree the slower cvar access will be.
The benefits of the cache are more visible with a higher number of
included modules due to the way Ruby looks up class variables. The
benchmark here includes 26 modules and shows with the cache, this branch
is 6.5x faster when accessing class variables.
```
compare-ruby: ruby 3.1.0dev (2021-03-15T06:22:34Z master 9e5105ca45) [x86_64-darwin19]
built-ruby: ruby 3.1.0dev (2021-03-15T12:12:44Z add-cache-for-clas.. c6be0093ae) [x86_64-darwin19]
| |compare-ruby|built-ruby|
|:--------|-----------:|---------:|
|vm_cvar | 5.681M| 36.980M|
| | -| 6.51x|
```
Benchmark.ips calling `ActiveRecord::Base.logger` from within a Rails
application. ActiveRecord::Base.logger has 71 ancestors. The more
ancestors a tree has, the more clear the speed increase. IE if Base had
only one ancestor we'd see no improvement. This benchmark is run on a
vanilla Rails application.
Benchmark code:
```ruby
require "benchmark/ips"
require_relative "config/environment"
Benchmark.ips do |x|
x.report "logger" do
ActiveRecord::Base.logger
end
end
```
Ruby 3.0 master / Rails 6.1:
```
Warming up --------------------------------------
logger 155.251k i/100ms
Calculating -------------------------------------
```
Ruby 3.0 with cvar cache / Rails 6.1:
```
Warming up --------------------------------------
logger 1.546M i/100ms
Calculating -------------------------------------
logger 14.857M (± 4.8%) i/s - 74.198M in 5.006202s
```
Lastly we ran a benchmark to demonstate the difference between master
and our cache when the number of modules increases. This benchmark
measures 1 ancestor, 30 ancestors, and 100 ancestors.
Ruby 3.0 master:
```
Warming up --------------------------------------
1 module 1.231M i/100ms
30 modules 432.020k i/100ms
100 modules 145.399k i/100ms
Calculating -------------------------------------
1 module 12.210M (± 2.1%) i/s - 61.553M in 5.043400s
30 modules 4.354M (± 2.7%) i/s - 22.033M in 5.063839s
100 modules 1.434M (± 2.9%) i/s - 7.270M in 5.072531s
Comparison:
1 module: 12209958.3 i/s
30 modules: 4354217.8 i/s - 2.80x (± 0.00) slower
100 modules: 1434447.3 i/s - 8.51x (± 0.00) slower
```
Ruby 3.0 with cvar cache:
```
Warming up --------------------------------------
1 module 1.641M i/100ms
30 modules 1.655M i/100ms
100 modules 1.620M i/100ms
Calculating -------------------------------------
1 module 16.279M (± 3.8%) i/s - 82.038M in 5.046923s
30 modules 15.891M (± 3.9%) i/s - 79.459M in 5.007958s
100 modules 16.087M (± 3.6%) i/s - 81.005M in 5.041931s
Comparison:
1 module: 16279458.0 i/s
100 modules: 16087484.6 i/s - same-ish: difference falls within error
30 modules: 15891406.2 i/s - same-ish: difference falls within error
```
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
To invalidate some callable method entries, we replace the entry in the
class. Most types of method entries are on the method table of the
origin class, but refinement entries without an orig_me are housed in
the method table of the class itself. They are there because refinements
take priority over prepended methods.
By unconditionally inserting a copy of the refinement entry into the
origin class, clearing the method cache created situations where there
are refinement entry duplicates in the lookup chain, leading to infinite
loops and other problems.
Update the replacement logic to use the right class that houses the
method entry. Also, be more selective about cache invalidation when
moving refinement entries for prepend. This avoids calling
clear_method_cache_by_id_in_class() before refinement entries are in the
place it expects.
[Bug #17806]
In every caller of `rb_class_ivar_set` it checks for the `RCLASS_IV_TBL`
and then creates it if it doesn't exist. Instead of repeating this in
every caller, this can be done once in `rb_class_ivar_set`.
It's important to only make the origin when the prepend goes
through, as the precense of the origin informs whether to do an
origin backfill.
This plus 2d877327e fix [Bug #17590].
Check for cyclic prepend before making any changes. This requires
scanning the module ancestor chain twice, but in general modules
do not have large numbers of ancestors.
