Fix indentation in vm_setivar_default --- vm_insnhelper.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) [Bug #19469] Fix crash when resizing generic iv list 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> --- internal/variable.h | 2 +- variable.c | 23 ++++++++++++++++++----- vm_insnhelper.c | 4 ++-- 3 files changed, 21 insertions(+), 8 deletions(-)
Only emit circular dependency warning for owned thread shields [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. --- internal/thread.h | 1 + load.c | 3 ++- spec/ruby/core/kernel/shared/require.rb | 11 +++++++++++ spec/ruby/fixtures/code/concurrent_require_fixture.rb | 4 ++++ test/ruby/test_require.rb | 3 --- thread.c | 11 +++++++++++ 6 files changed, 29 insertions(+), 4 deletions(-) create mode 100644 spec/ruby/fixtures/code/concurrent_require_fixture.rb Use Thread.pass until thread.stop? to wait for thread to block [Bug #19415] It should be more reliable --- spec/ruby/fixtures/code/concurrent_require_fixture.rb | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
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>
We want to hint to the compiler that it's likely that the BOP is unredefined (the bit is 0). Previously we were accidentally hinting to the compiler that it was non-zero due to a misplaced parenthesis.
Prior to this commit the `OPTIMIZED_CMP` macro relied on a method lookup
to determine whether `<=>` was overridden. The result of the lookup was
cached, but only for the duration of the specific method that
initialized the cmp_opt_data cache structure.
With this method lookup, `[x,y].max` is slower than doing `x > y ?
x : y` even though there's an optimized instruction for "new array max".
(John noticed somebody a proposed micro-optimization based on this fact
in https://github.com/mastodon/mastodon/pull/19903.)
```rb
a, b = 1, 2
Benchmark.ips do |bm|
bm.report('conditional') { a > b ? a : b }
bm.report('method') { [a, b].max }
bm.compare!
end
```
Before:
```
Comparison:
conditional: 22603733.2 i/s
method: 19820412.7 i/s - 1.14x (± 0.00) slower
```
This commit replaces the method lookup with a new CMP basic op, which
gives the examples above equivalent performance.
After:
```
Comparison:
method: 24022466.5 i/s
conditional: 23851094.2 i/s - same-ish: difference falls within
error
```
Relevant benchmarks show an improvement to Array#max and Array#min when
not using the optimized newarray_max instruction as well. They are
noticeably faster for small arrays with the relevant types, and the same
or maybe a touch faster on larger arrays.
```
$ make benchmark COMPARE_RUBY=<master@5958c305> ITEM=array_min
$ make benchmark COMPARE_RUBY=<master@5958c305> ITEM=array_max
```
The benchmarks added in this commit also look generally improved.
Co-authored-by: John Hawthorn <jhawthorn@github.com>
This commit moves ruby_basic_operators and the unredefined macros out of vm_core.h and into basic_operators.h so that we can use them more broadly in places where we currently use a method look up via `rb_method_basic_definition_p` (e.g. object.c, numeric.c, complex.c, enum.c, but also in internal/compar.h after introducing BOP_CMP and elsewhere if we introduce more BOPs) The most controversial part of this change is probably moving redefined_flag out of rb_vm_t. [vm_opt_method_def_table and vm_opt_mid_table](https://github.com/ruby/ruby/blob/9da2a5204f32a4f2ce135fddde2abb6e07d647e9/vm.c) are not part of rb_vm_t either, and I think this fits well with those. But more significantly it seems to result in one fewer instruction. For example: Before: ``` (lldb) disassemble -n vm_opt_str_freeze miniruby`vm_exec_core: miniruby[0x10028233e] <+14558>: movq 0x11a86b(%rip), %rax ; ruby_current_vm_ptr miniruby[0x100282345] <+14565>: testb $0x4, 0x242c(%rax) ``` After: ``` (lldb) disassemble -n vm_opt_str_freeze ruby`vm_exec_core: ruby[0x100280ebe] <+14510>: testb $0x4, 0x120147(%rip) ; ruby_vm_redefined_flag + 43 ``` Co-authored-by: John Hawthorn <jhawthorn@github.com>