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.
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.
Tabs were expanded because the file did not have any tab indentation in unedited lines.
Please update your editor config, and use misc/expand_tabs.rb in the pre-commit hook.
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 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)
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.
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
* process.c: Add Process._fork
This API is supposed for application monitoring libraries to hook fork
event.
[Feature #17795]
Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
`RubyVM.keep_script_lines` enables to keep script lines
for each ISeq and AST. This feature is for debugger/REPL
support.
```ruby
RubyVM.keep_script_lines = true
RubyVM::keep_script_lines = true
eval("def foo = nil\ndef bar = nil")
pp RubyVM::InstructionSequence.of(method(:foo)).script_lines
```
In an effort to simplify the logic YJIT generates for accessing instance
variable, YJIT ensures that a given name-to-index mapping exists at
compile time. In the case that the mapping doesn't exist, it was created
by using rb_ivar_set() with Qundef on the sample object we see at
compile time. This hack isn't fine if the sample object happens to be
frozen, in which case YJIT would raise a FrozenError unexpectedly.
To deal with this, make a new function that only reserves the mapping
but doesn't touch the object. This is rb_obj_ensure_iv_index_mapping().
This new function superceeds the functionality of rb_iv_index_tbl_lookup()
so it was removed.
Reported by and includes a test case from John Hawthorn <john@hawthorn.email>
Fixes: GH-282
When YJIT make calls to routines without reconstructing interpreter
state through jit_prepare_routine_call(), it relies on the routine to
never allocate, raise, and push/pop control frames. Comment about this
on the routines that YJTI calls.
This is probably something we should dynamically verify on debug builds.
It's hard to statically verify this as it requires verifying all
functions in the call tree. Maybe something to look at in the future.
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 commit removes T_PAYLOAD since the new VWA implementation no longer
requires T_PAYLOAD types.
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>
This commit removes T_PAYLOAD since the new VWA implementation no longer
requires T_PAYLOAD types.
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
... as per ko1's preference. He is preparing to extend this feature to
ISeq for his new debugger. He prefers "keep" to "save" for this wording.
This API is internal and not included in any released version, so I
change it in advance.
Make `RUBY_VERSION_SINCE` and `RUBY_VERSION_BEFORE` to take major
and minor numbers so usable also in preprocessor directives. Old
macros are renamed with "STRING".
ndigits higher than 14 can result in values that are slightly too
large due to floating point limitations. Converting to rational
for the calculation and then back to float fixes these issues.
Fixes [Bug #14635]
Fixes [Bug #17183]
Co-authored by: Yusuke Endoh <mame@ruby-lang.org>
Kevin Newton
John Hawthorn
Peter Zhu
Nobuyoshi Nakada
git
Yusuke Endoh
Matt Valentine-House
Koichi Sasada
Alan Wu
S-H-GAMELINKS
Samuel Williams
卜部昌平
Jeremy Evans
Peter Zhu