Given that signleton classes don't have an allocator,
we can re-use these bytes to store the attached object
in `rb_classext_struct` without making it larger.
Right now the attached object is stored as an instance variable
and all the call sites that either get or set it have to know how it's
stored.
It's preferable to hide this implementation detail behind accessors
so that it is easier to change how it's stored.
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>
Previously, when we froze an object, we froze
`RCLASS_ORIGIN(object.singleton_class)`, which didn't freeze
`object.singleton_class` when it has some prepended modules.
Origin iclass are internal objects and users can't interact with
them through Kernel#freeze?, Kernel#freeze, or any mutation method
that checks the frozen status. So we shouldn't touch the origin
iclasses when the frozen status should be visible.
[Bug #19169]
In 274870bd5434ab64ac3a3c9db9aa27d262c1d6d6 we gained the ability to
make an educated guess at the max_iv_count of a class based on its
initialize method. This commit makes subclasses inherit their super's
max_iv_count, which makes the estimate work in cases that the subclass
does not have an initialize method.
This commit adds a `capacity` field to shapes, and adds shape
transitions whenever an object's capacity changes. Objects which are
allocated out of a bigger size pool will also make a transition from the
root shape to the shape with the correct capacity for their size pool
when they are allocated.
This commit will allow us to remove numiv from objects completely, and
will also mean we can guarantee that if two objects share shapes, their
IVs are in the same positions (an embedded and extended object cannot
share shapes). This will enable us to implement ivar sets in YJIT using
object shapes.
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
* Avoid RCLASS_IV_TBL in marshal.c
* Avoid RCLASS_IV_TBL for class names
* Avoid RCLASS_IV_TBL for autoload
* Avoid RCLASS_IV_TBL for class variables
* Avoid copying RCLASS_IV_TBL onto ICLASSes
* Use object shapes for Class and Module IVs
Before object shapes, we were using class serial to invalidate
inline caches. Now that we use shape_id for inline cache keys,
the class serial is unnecessary.
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Implements [Feature #12084]
Returns the object for which the receiver is the singleton class, or
raises TypeError if the receiver is not a singleton class.
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.
While walking over the list of subclasses for `include` and friends, we
check whether the subclass is a garbage object. After the check, we
allocate objects which might trigger GC and make the subclass garbage,
even though before the allocation the subclass was not garbage. This is
a sort of time-of-check-time-of-use issue.
Fix this by saving the weak reference to a local variable, upgrading it
to a strong reference while we do the allocation. It makes the code look
slightly nicer even if it doesn't fix any runtime issues.
Previously in some when classes were duped (specifically those with a
prepended module), they would not correctly have their "superclasses"
array or depth filled in.
This could cause ancestry checks (like is_a? and Module comparisons) to
return incorrect results.
This happened because rb_mod_init_copy builds origin classes in an order
that doesn't have the super linked list fully connected until it's
finished. This commit fixes the previous issue by calling
rb_class_update_superclasses before returning the cloned class. This is
similar to what's already done in make_metaclass.
This commit reintroduces finer-grained constant cache invalidation.
After 8008fb7 got merged, it was causing issues on token-threaded
builds (such as on Windows).
The issue was that when you're iterating through instruction sequences
and using the translator functions to get back the instruction structs,
you're either using `rb_vm_insn_null_translator` or
`rb_vm_insn_addr2insn2` depending if it's a direct-threading build.
`rb_vm_insn_addr2insn2` does some normalization to always return to
you the non-trace version of whatever instruction you're looking at.
`rb_vm_insn_null_translator` does not do that normalization.
This means that when you're looping through the instructions if you're
trying to do an opcode comparison, it can change depending on the type
of threading that you're using. This can be very confusing. So, this
commit creates a new translator function
`rb_vm_insn_normalizing_translator` to always return the non-trace
version so that opcode comparisons don't have to worry about different
configurations.
[Feature #18589]
This reverts commits for [Feature #18589]:
* 8008fb7352
"Update formatting per feedback"
* 8f6eaca2e1
"Delete ID from constant cache table if it becomes empty on ISEQ free"
* 629908586b
"Finer-grained inline constant cache invalidation"
MSWin builds on AppVeyor have been crashing since the merger.
Current behavior - caches depend on a global counter. All constant mutations cause caches to be invalidated.
```ruby
class A
B = 1
end
def foo
A::B # inline cache depends on global counter
end
foo # populate inline cache
foo # hit inline cache
C = 1 # global counter increments, all caches are invalidated
foo # misses inline cache due to `C = 1`
```
Proposed behavior - caches depend on name components. Only constant mutations with corresponding names will invalidate the cache.
```ruby
class A
B = 1
end
def foo
A::B # inline cache depends constants named "A" and "B"
end
foo # populate inline cache
foo # hit inline cache
C = 1 # caches that depend on the name "C" are invalidated
foo # hits inline cache because IC only depends on "A" and "B"
```
Examples of breaking the new cache:
```ruby
module C
# Breaks `foo` cache because "A" constant is set and the cache in foo depends
# on "A" and "B"
class A; end
end
B = 1
```
We expect the new cache scheme to be invalidated less often because names aren't frequently reused. With the cache being invalidated less, we can rely on its stability more to keep our constant references fast and reduce the need to throw away generated code in YJIT.
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.
Previously, we would build a new `superclasses` array for each class,
even though for all immediate subclasses of a class, the array is
identical.
This avoids duplicating the arrays on leaf classes (those without
subclasses) by calculating and storing a "superclasses including self"
array on a class when it's first inherited and sharing that among all
superclasses.
An additional trick used is that the "superclass array including self"
is valid as "self"'s superclass array. It just has it's own class at the
end. We can use this to avoid an extra pointer of storage and can use
one bit of a flag to track that we've "upgraded" the array.
Previously when checking ancestors, we would walk all the way up the
ancestry chain checking each parent for a matching class or module.
I believe this was especially unfriendly to CPU cache since for each
step we need to check two cache lines (the class and class ext).
This check is used quite often in:
* case statements
* rescue statements
* Calling protected methods
* Class#is_a?
* Module#===
* Module#<=>
I believe it's most common to check a class against a parent class, to
this commit aims to improve that (unfortunately does not help checking
for an included Module).
This is done by storing on each class the number and an array of all
parent classes, in order (BasicObject is at index 0). Using this we can
check whether a class is a subclass of another in constant time since we
know the location to expect it in the hierarchy.
On 32-bit systems, VWA causes class_serial to not be aligned (it only
guarantees 4 byte alignment but class_serial is 8 bytes and requires 8
byte alignment). This commit uses a hack to allocate class_serial
through malloc. Once VWA allocates with 8 byte alignment in the future,
we will revert this commit.
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]
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]
Matt Valentine-House
Nobuyoshi Nakada
Takashi Kokubun
Jean Boussier
eileencodes
zverok
Alan Wu
John Hawthorn
S-H-GAMELINKS
Jemma Issroff
Ufuk Kayserilioglu
Jeremy Evans
Peter Zhu
Kevin Newton
Jean Boussier
Yusuke Endoh