Remove !USE_RVARGC code
[Feature #19579]
The Variable Width Allocation feature was turned on by default in Ruby
3.2. Since then, we haven't received bug reports or backports to the
non-Variable Width Allocation code paths, so we assume that nobody is
using it. We also don't plan on maintaining the non-Variable Width
Allocation code, so we are going to remove it.
[Feature #18885]
For now, the optimizations performed are:
- Run a major GC
- Compact the heap
- Promote all surviving objects to oldgen
Other optimizations may follow.
These classes don't belong in gc.c as they're not actually part of the
GC. This commit refactors the code by moving all the code into a
weakmap.c file.
This makes the behavior of classes and modules when there are too many instance variables match the behavior of objects with too many instance variables.
The following script can sometimes trigger a crash:
```ruby
GC.stress = true
class Array
def foo(bool)
if bool
@a = 1
@b = 2
@c = 1
else
@c = 1
end
end
end
obj = []
obj.foo(true)
obj2 = []
obj2.foo(false)
obj3 = []
obj3.foo(true)
```
This is because vm_setivar_default calls rb_ensure_generic_iv_list_size
to resize the iv list. However, the call to gen_ivtbl_resize reallocs
the iv list, and then inserts into the generic iv table. If the
st_insert triggers a GC then the old iv list will be read during
marking, causing a use-after-free bug.
Co-Authored-By: Jemma Issroff <jemmaissroff@gmail.com>
This reverts commit 35136e1e9c.
test-spec has been failing since this revision.
.github/workflows/compilers.yml:82
https://github.com/ruby/ruby/actions/runs/4276884159/jobs/7445299562
```
env:
# Minimal flags to pass the check.
default_cc: 'gcc-11 -fcf-protection -Wa,--generate-missing-build-notes=yes'
optflags: '-O2'
LDFLAGS: '-Wl,-z,now'
# FIXME: Drop skipping options
# https://bugs.ruby-lang.org/issues/18061
# https://sourceware.org/annobin/annobin.html/Test-pie.html
TEST_ANNOCHECK_OPTS: "--skip-pie --skip-gaps"
```
Failure:
```
1)
An exception occurred during: Kernel#require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:317
Kernel#require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'
2)
An exception occurred during: Kernel#require ($LOADED_FEATURES) stores an absolute path
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:330
Kernel#require ($LOADED_FEATURES) stores an absolute path ERROR
LeakError: Closed file descriptor: 8
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'
3)
An exception occurred during: Kernel#require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:535
Kernel#require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded ERROR
LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'
4)
An exception occurred during: Kernel#require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:551
Kernel#require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded ERROR
LeakError: Leaked file descriptor: 9 : #<File:../code/load_fixture.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'
5)
An exception occurred during: Kernel#require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:563
Kernel#require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required ERROR
LeakError: Closed file descriptor: 8
Closed file descriptor: 9
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:5:in `<top (required)>'
6)
An exception occurred during: Kernel.require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:317
Kernel.require (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'
7)
An exception occurred during: Kernel.require ($LOADED_FEATURES) stores an absolute path
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:330
Kernel.require ($LOADED_FEATURES) stores an absolute path ERROR
LeakError: Closed file descriptor: 8
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'
8)
An exception occurred during: Kernel.require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:535
Kernel.require ($LOADED_FEATURES) does not load a non-canonical path for a file already loaded ERROR
LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'
9)
An exception occurred during: Kernel.require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:551
Kernel.require ($LOADED_FEATURES) does not load a ../ relative path for a file already loaded ERROR
LeakError: Leaked file descriptor: 9 : #<File:../code/load_fixture.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'
10)
An exception occurred during: Kernel.require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required
/__w/ruby/ruby/src/spec/ruby/core/kernel/shared/require.rb:563
Kernel.require ($LOADED_FEATURES) complex, enumerator, rational, thread, ruby2_keywords are already required ERROR
LeakError: Closed file descriptor: 8
Closed file descriptor: 9
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_spec.rb:23:in `<top (required)>'
11)
An exception occurred during: Kernel#require_relative with a relative path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:197
Kernel#require_relative with a relative path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:4:in `<top (required)>'
12)
An exception occurred during: Kernel#require_relative with a relative path ($LOADED_FEATURES) stores an absolute path
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:205
Kernel#require_relative with a relative path ($LOADED_FEATURES) stores an absolute path ERROR
LeakError: Closed file descriptor: 8
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:4:in `<top (required)>'
13)
An exception occurred during: Kernel#require_relative with an absolute path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:399
Kernel#require_relative with an absolute path (file extensions) does not load a C-extension file if a complex-extensioned .rb file is already loaded ERROR
LeakError: Leaked file descriptor: 8 : #<File:/__w/ruby/ruby/src/spec/ruby/fixtures/code/load_fixture.ext.rb>
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:277:in `<top (required)>'
14)
An exception occurred during: Kernel#require_relative with an absolute path ($LOAD_FEATURES) stores an absolute path
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:407
Kernel#require_relative with an absolute path ($LOAD_FEATURES) stores an absolute path ERROR
LeakError: Closed file descriptor: 8
/__w/ruby/ruby/src/spec/ruby/core/kernel/require_relative_spec.rb:277:in `<top (required)>'
```
When loading Ruby source files, we can save the result of
successful opens as open(2)/openat(2) are a fairly expensive
syscalls. This also avoids a time-of-check-to-time-of-use
(TOCTTOU) problem.
This reduces open(2) syscalls during `require'; but should be
most apparent when users have a small $LOAD_PATH. Users with
large $LOAD_PATH will benefit less since there'll be more
open(2) failures due to ENOENT.
With `strace -c -e openat ruby -e exit' under Linux, this
results in a ~14% reduction of openat(2) syscalls
(glibc uses openat(2) to implement open(2)).
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
0.00 0.000000 0 296 110 openat
0.00 0.000000 0 254 110 openat
Additionally, the introduction of `struct ruby_file_load_state'
may make future optimizations more apparent.
This change cannot benefit binary (.so) loading since the
dlopen(3) API requires a filename and I'm not aware of an
alternative that takes a pre-existing FD. In typical
situations, Ruby source files outnumber the mount of .so
files.
If the previous instruction is not a leaf instruction, then the PC was
incremented before the instruction was ran (meaning the currently
executing instruction is actually the previous instruction), so we
should not increment the PC otherwise we will calculate the source
line for the next instruction.
This bug can be reproduced in the following script:
```
require "objspace"
ObjectSpace.trace_object_allocations_start
a =
1.0 / 0.0
p [ObjectSpace.allocation_sourceline(a), ObjectSpace.allocation_sourcefile(a)]
```
Which outputs: [4, "test.rb"]
This is incorrect because the object was allocated on line 10 and not
line 4. The behaviour is correct when we use a leaf instruction (e.g.
if we replaced `1.0 / 0.0` with `"hello"`), then the output is:
[10, "test.rb"].
[Bug #19456]
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.
This patch is follo-up of 0a82bfe.
Without this patch, if env is escaped (Proc'ed), strange svar
can be touched.
This patch tracks escaped env and use it.
[Bug #19415]
If multiple threads attemps to load the same file concurrently
it's not a circular dependency issue.
So we check that the existing ThreadShield is owner by the current
fiber before warning about circular dependencies.
[Bug #19415]
If multiple threads attemps to load the same file concurrently
it's not a circular dependency issue.
So we check that the existing ThreadShield is owner by the current
fiber before warning about circular dependencies.
* use correct svar
Without this patch, svar location is used "nearest Ruby frame".
It is almost correct but it doesn't correct when the `each` method
is written in Ruby.
```ruby
class C
include Enumerable
def each
%w(bar baz).each{|e| yield e}
end
end
C.new.grep(/(b.)/){|e| p [$1, e]}
```
This patch fix this issue by traversing ifunc's cfp.
Note that if cfp doesn't specify this Thread's cfp stack, reserved
svar location (`ec->root_svar`) is used.
* make yjit-bindgen
---------
Co-authored-by: Takashi Kokubun <takashikkbn@gmail.com>
Instance variables held in gen_ivtbl are marked with rb_gc_mark. It
prevents the referenced objects from moving, which is bad for copying
garbage collectors.
This commit allows those instance variables to be updated during
gc_update_object_references.
This commit adds rb_gc_mark_and_move which takes a pointer to an object
and marks it during marking phase and updates references during compaction.
This allows for marking and reference updating to be combined into a
single function, which reduces code duplication and prevents bugs if
marking and reference updating goes out of sync.
This commit also implements rb_gc_mark_and_move on iseq as an example.
This commit moves the classpath (and tmp_classpath) from instance
variables to the rb_classext_t. This improves performance as we no
longer need to set an instance variable when assigning a classpath to
a class.
I benchmarked with the following script:
```ruby
name = :MyClass
puts(Benchmark.measure do
10_000_000.times do |i|
Object.const_set(name, Class.new)
Object.send(:remove_const, name)
end
end)
```
Before this patch:
```
5.440119 0.025264 5.465383 ( 5.467105)
```
After this patch:
```
4.889646 0.028325 4.917971 ( 4.942678)
```
On a hash miss we need to call default if it is redefined in order to
return the default value to be used. Previously we checked this with
rb_method_basic_definition_p, which avoids the method call but requires
a method lookup.
This commit replaces the previous check with BASIC_OP_UNREDEFINED_P and
a new BOP_DEFAULT. We still need to fall back to
rb_method_basic_definition_p when called on a subclasss of hash.
| |compare-ruby|built-ruby|
|:---------------|-----------:|---------:|
|hash_aref_miss | 2.692| 3.531|
| | -| 1.31x|
Co-authored-by: Daniel Colson <danieljamescolson@gmail.com>
Co-authored-by: "Ian C. Anderson" <ian@iancanderson.com>
Co-authored-by: Jack McCracken <me@jackmc.xyz>
SIZE_POOL_COUNT is a GC macro, it should belong in gc.h and not shape.h.
SIZE_POOL_COUNT doesn't depend on shape.h so we can have shape.h depend
on gc.h.
Co-Authored-By: Matt Valentine-House <matt@eightbitraptor.com>
When an object becomes "too complex" (in other words it has too many
variations in the shape tree), we transition it to use a "too complex"
shape and use a hash for storing instance variables.
Without this patch, there were rare cases where shape tree growth could
"explode" and cause performance degradation on what would otherwise have
been cached fast paths.
This patch puts a limit on shape tree growth, and gracefully degrades in
the rare case where there could be a factorial growth in the shape tree.
For example:
```ruby
class NG; end
HUGE_NUMBER.times do
NG.new.instance_variable_set(:"@unique_ivar_#{_1}", 1)
end
```
We consider objects to be "too complex" when the object's class has more
than SHAPE_MAX_VARIATIONS (currently 8) leaf nodes in the shape tree and
the object introduces a new variation (a new leaf node) associated with
that class.
For example, new variations on instances of the following class would be
considered "too complex" because those instances create more than 8
leaves in the shape tree:
```ruby
class Foo; end
9.times { Foo.new.instance_variable_set(":@uniq_#{_1}", 1) }
```
However, the following class is *not* too complex because it only has
one leaf in the shape tree:
```ruby
class Foo
def initialize
@a = @b = @c = @d = @e = @f = @g = @h = @i = nil
end
end
9.times { Foo.new }
``
This case is rare, so we don't expect this change to impact performance
of most applications, but it needs to be handled.
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Count how many "variations" each class creates. A "variation" is a a
unique ordering of instance variables on a particular class. This can
also be thought of as a branch in the shape tree.
For example, the following Foo class will have 2 variations:
```ruby
class Foo ; end
Foo.new.instance_variable_set(:@a, 1) # case 1: creates one variation
Foo.new.instance_variable_set(:@b, 1) # case 2: creates another variation
foo = Foo.new
foo.instance_variable_set(:@a, 1) # does not create a new variation
foo.instance_variable_set(:@b, 1) # does not create a new variation (a continuation of the variation in case 1)
```
We will use this number to limit the amount of shapes that a class can
create and fallback to using a hash iv lookup.
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Peter Zhu
Matt Valentine-House
Aaron Patterson
Jean Boussier
Takashi Kokubun
HParker
Eric Wong
Koichi Sasada
Jean byroot Boussier
Kunshan Wang
Nobuyoshi Nakada
John Hawthorn
Jemma Issroff