64 Commits

Author SHA1 Message Date
John Hawthorn
02f1554224
Implement object shapes for T_CLASS and T_MODULE (#6637)
* 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
2022-10-31 14:05:37 -07:00
Jemma Issroff
a11952dac1 Rename iv_count on shapes to next_iv_index
`iv_count` is a misleading name because when IVs are unset, the new
shape doesn't decrement this value. `next_iv_count` is an accurate, and
more descriptive name.
2022-10-21 14:57:34 -07:00
Jemma Issroff
0aaa6133ed Transition frozen string to frozen root shape
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
2022-10-19 11:06:19 -07:00
Aaron Patterson
e5058b58c2
Only expose Ruby Shape API if VM_CHECK_MODE is enabled 2022-10-13 13:11:01 -07:00
Aaron Patterson
107531583c Unwrap shape id as unsigned int
Shape IDs are unsigned.  This commit unwraps the shape id as an unsigned
int, which will automatically raise an argument error and also eliminate
a compilation warning.
2022-10-12 09:56:11 -07:00
Nobuyoshi Nakada
70bc8cc6c2
Adjust indents [ci skip] 2022-10-12 22:22:04 +09:00
Jemma Issroff
913979bede
Make inline cache reads / writes atomic with object shapes
Prior to this commit, we were reading and writing ivar index and
shape ID in inline caches in two separate instructions when
getting and setting ivars. This meant there was a race condition
with ractors and these caches where one ractor could change
a value in the cache while another was still reading from it.

This commit instead reads and writes shape ID and ivar index to
inline caches atomically so there is no longer a race condition.

Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Co-Authored-By: John Hawthorn <john@hawthorn.email>
2022-10-11 08:40:56 -07:00
Jemma Issroff
ad63b668e2
Revert "Revert "This commit implements the Object Shapes technique in CRuby.""
This reverts commit 9a6803c90b817f70389cae10d60b50ad752da48f.
2022-10-11 08:40:56 -07:00
Aaron Patterson
9a6803c90b
Revert "This commit implements the Object Shapes technique in CRuby."
This reverts commit 68bc9e2e97d12f80df0d113e284864e225f771c2.
2022-09-30 16:01:50 -07:00
eileencodes
0ab0229c11 Fix frozen object inspect
In the rails/rails CI build for Ruby master we found that some tests
were failing due to inspect on a frozen object being incorrect.

An object's instance variable count was incorrect when frozen causing
the object's inspect to not splat out the object.

This fixes the issue and adds a test for inspecting frozen objects.

Co-Authored-By: Jemma Issroff <jemmaissroff@gmail.com>
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
2022-09-30 13:57:59 -07:00
Aaron Patterson
3e7c42a239
Shapes wrappers shouldn't mark the shape
We don't allocate shapes out of the GC anymore, so we shouldn't mark
those pointers.
2022-09-28 09:24:35 -07:00
Jemma Issroff
d594a5a8bd
This commit implements the Object Shapes technique in CRuby.
Object Shapes is used for accessing instance variables and representing the
"frozenness" of objects.  Object instances have a "shape" and the shape
represents some attributes of the object (currently which instance variables are
set and the "frozenness").  Shapes form a tree data structure, and when a new
instance variable is set on an object, that object "transitions" to a new shape
in the shape tree.  Each shape has an ID that is used for caching. The shape
structure is independent of class, so objects of different types can have the
same shape.

For example:

```ruby
class Foo
  def initialize
    # Starts with shape id 0
    @a = 1 # transitions to shape id 1
    @b = 1 # transitions to shape id 2
  end
end

class Bar
  def initialize
    # Starts with shape id 0
    @a = 1 # transitions to shape id 1
    @b = 1 # transitions to shape id 2
  end
end

foo = Foo.new # `foo` has shape id 2
bar = Bar.new # `bar` has shape id 2
```

Both `foo` and `bar` instances have the same shape because they both set
instance variables of the same name in the same order.

This technique can help to improve inline cache hits as well as generate more
efficient machine code in JIT compilers.

This commit also adds some methods for debugging shapes on objects.  See
`RubyVM::Shape` for more details.

For more context on Object Shapes, see [Feature: #18776]

Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Co-Authored-By: Eileen M. Uchitelle <eileencodes@gmail.com>
Co-Authored-By: John Hawthorn <john@hawthorn.email>
2022-09-28 08:26:21 -07:00
Aaron Patterson
06abfa5be6
Revert this until we can figure out WB issues or remove shapes from GC
Revert "* expand tabs. [ci skip]"

This reverts commit 830b5b5c351c5c6efa5ad461ae4ec5085e5f0275.

Revert "This commit implements the Object Shapes technique in CRuby."

This reverts commit 9ddfd2ca004d1952be79cf1b84c52c79a55978f4.
2022-09-26 16:10:11 -07:00
Jemma Issroff
9ddfd2ca00 This commit implements the Object Shapes technique in CRuby.
Object Shapes is used for accessing instance variables and representing the
"frozenness" of objects.  Object instances have a "shape" and the shape
represents some attributes of the object (currently which instance variables are
set and the "frozenness").  Shapes form a tree data structure, and when a new
instance variable is set on an object, that object "transitions" to a new shape
in the shape tree.  Each shape has an ID that is used for caching. The shape
structure is independent of class, so objects of different types can have the
same shape.

For example:

```ruby
class Foo
  def initialize
    # Starts with shape id 0
    @a = 1 # transitions to shape id 1
    @b = 1 # transitions to shape id 2
  end
end

class Bar
  def initialize
    # Starts with shape id 0
    @a = 1 # transitions to shape id 1
    @b = 1 # transitions to shape id 2
  end
end

foo = Foo.new # `foo` has shape id 2
bar = Bar.new # `bar` has shape id 2
```

Both `foo` and `bar` instances have the same shape because they both set
instance variables of the same name in the same order.

This technique can help to improve inline cache hits as well as generate more
efficient machine code in JIT compilers.

This commit also adds some methods for debugging shapes on objects.  See
`RubyVM::Shape` for more details.

For more context on Object Shapes, see [Feature: #18776]

Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Co-Authored-By: Eileen M. Uchitelle <eileencodes@gmail.com>
Co-Authored-By: John Hawthorn <john@hawthorn.email>
2022-09-26 09:21:30 -07:00