Set has been an autoloaded standard library since Ruby 3.2.
The standard library Set is less efficient than it could be, as it
uses Hash for storage, which stores unnecessary values for each key.
Implementation details:
* Core Set uses a modified version of `st_table`, named `set_table`.
than `s/st_/set_/`, the main difference is that the stored records
do not have values, making them 1/3 smaller. `st_table_entry` stores
`hash`, `key`, and `record` (value), while `set_table_entry` only
stores `hash` and `key`. This results in large sets using ~33% less
memory compared to stdlib Set. For small sets, core Set uses 12% more
memory (160 byte object slot and 64 malloc bytes, while stdlib set
uses 40 for Set and 160 for Hash). More memory is used because
the set_table is embedded and 72 bytes in the object slot are
currently wasted. Hopefully we can make this more efficient and have
it stored in an 80 byte object slot in the future.
* All methods are implemented as cfuncs, except the pretty_print
methods, which were moved to `lib/pp.rb` (which is where the
pretty_print methods for other core classes are defined). As is
typical for core classes, internal calls call C functions and
not Ruby methods. For example, to check if something is a Set,
`rb_obj_is_kind_of` is used, instead of calling `is_a?(Set)` on the
related object.
* Almost all methods use the same algorithm that the pure-Ruby
implementation used. The exception is when calling `Set#divide` with a
block with 2-arity. The pure-Ruby method used tsort to implement this.
I developed an algorithm that only allocates a single intermediate
hash and does not need tsort.
* The `flatten_merge` protected method is no longer necessary, so it
is not implemented (it could be).
* Similar to Hash/Array, subclasses of Set are no longer reflected in
`inspect` output.
* RDoc from stdlib Set was moved to core Set, with minor updates.
This includes a comprehensive benchmark suite for all public Set
methods. As you would expect, the native version is faster in the
vast majority of cases, and multiple times faster in many cases.
There are a few cases where it is significantly slower:
* Set.new with no arguments (~1.6x)
* Set#compare_by_identity for small sets (~1.3x)
* Set#clone for small sets (~1.5x)
* Set#dup for small sets (~1.7x)
These are slower as Set does not currently use the AR table
optimization that Hash does, so a new set_table is initialized for
each call. I'm not sure it's worth the complexity to have an AR
table-like optimization for small sets (for hashes it makes sense,
as small hashes are used everywhere in Ruby).
The rbs and repl_type_completor bundled gems will need updates to
support core Set. The pull request marks them as allowed failures.
This passes all set tests with no changes. The following specs
needed modification:
* Modifying frozen set error message (changed for the better)
* `Set#divide` when passed a 2-arity block no longer yields the same
object as both the first and second argument (this seems like an issue
with the previous implementation).
* Set-like objects that override `is_a?` such that `is_a?(Set)` return
`true` are no longer treated as Set instances.
* `Set.allocate.hash` is no longer the same as `nil.hash`
* `Set#join` no longer calls `Set#to_a` (it calls the underlying C
function).
* `Set#flatten_merge` protected method is not implemented.
Previously, `set.rb` added a `SortedSet` autoload, which loads
`set/sorted_set.rb`. This replaces the `Set` autoload in `prelude.rb`
with a `SortedSet` autoload, but I recommend removing it and
`set/sorted_set.rb`.
This moves `test/set/test_set.rb` to `test/ruby/test_set.rb`,
reflecting that switch to a core class. This does not move the spec
files, as I'm not sure how they should be handled.
Internally, this uses the st_* types and functions as much as
possible, and only adds set_* types and functions as needed.
The underlying set_table implementation is stored in st.c, but
there is no public C-API for it, nor is there one planned, in
order to keep the ability to change the internals going forward.
For internal uses of st_table with Qtrue values, those can
probably be replaced with set_table. To do that, include
internal/set_table.h. To handle symbol visibility (rb_ prefix),
internal/set_table.h uses the same macro approach that
include/ruby/st.h uses.
The Set class (rb_cSet) and all methods are defined in set.c.
There isn't currently a C-API for the Set class, though C-API
functions can be added as needed going forward.
Implements [Feature #21216]
Co-authored-by: Jean Boussier <jean.boussier@gmail.com>
Co-authored-by: Oliver Nutter <mrnoname1000@riseup.net>
* Assert everything is compiled in test_zjit
* Update a comment on rb_zjit_assert_compiles
Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>
* Add a comment about assert_compiles
* Actually use pipe_fd
---------
Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>
* YJIT: Replace Array#each only when YJIT is enabled
* Add comments about BUILTIN_ATTR_C_TRACE
* Make Ruby Array#each available with --yjit as well
* Fix all paths that expect a C location
* Use method_basic_definition_p to detect patches
* Copy a comment about C_TRACE flag to compilers
* Rephrase a comment about add_yjit_hook
* Give METHOD_ENTRY_BASIC flag to Array#each
* Add --yjit-c-builtin option
* Allow inconsistent source_location in test-spec
* Refactor a check of BUILTIN_ATTR_C_TRACE
* Set METHOD_ENTRY_BASIC without touching vm->running
Our current implementation of rb_postponed_job_register suffers from
some safety issues that can lead to interpreter crashes (see bug #1991).
Essentially, the issue is that jobs can be called with the wrong
arguments.
We made two attempts to fix this whilst keeping the promised semantics,
but:
* The first one involved masking/unmasking when flushing jobs, which
was believed to be too expensive
* The second one involved a lock-free, multi-producer, single-consumer
ringbuffer, which was too complex
The critical insight behind this third solution is that essentially the
only user of these APIs are a) internal, or b) profiling gems.
For a), none of the usages actually require variable data; they will
work just fine with the preregistration interface.
For b), generally profiling gems only call a single callback with a
single piece of data (which is actually usually just zero) for the life
of the program. The ringbuffer is complex because it needs to support
multi-word inserts of job & data (which can't be atomic); but nobody
actually even needs that functionality, really.
So, this comit:
* Introduces a pre-registration API for jobs, with a GVL-requiring
rb_postponed_job_prereigster, which returns a handle which can be
used with an async-signal-safe rb_postponed_job_trigger.
* Deprecates rb_postponed_job_register (and re-implements it on top of
the preregister function for compatability)
* Moves all the internal usages of postponed job register
pre-registration
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 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>
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>
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>
* Rename `rb_scheduler` to `rb_fiber_scheduler`.
* Use public interface if available.
* Use `rb_check_funcall` where possible.
* Don't use `unblock` unless the fiber was non-blocking.
* Add buffer protocol
* Modify for some review comments
* Per-object buffer availability
* Rename to MemoryView from Buffer and make compilable
* Support integral repeat count in memory view format
* Support 'x' for padding bytes
* Add rb_memory_view_parse_item_format
* Check type in rb_memory_view_register
* Update dependencies in common.mk
* Add test of MemoryView
* Add test of rb_memory_view_init_as_byte_array
* Add native size format test
* Add MemoryView test utilities
* Add test of rb_memory_view_fill_contiguous_strides
* Skip spaces in format string
* Support endianness specifiers
* Update documentation
* Support alignment
* Use RUBY_ALIGNOF
* Fix format parser to follow the pack format
* Support the _ modifier
* Parse count specifiers in get_format_size function.
* Use STRUCT_ALIGNOF
* Fix test
* Fix test
* Fix total size for the case with tail padding
* Fix rb_memory_view_get_item_pointer
* Fix rb_memory_view_parse_item_format again
This commit introduces Ractor mechanism to run Ruby program in
parallel. See doc/ractor.md for more details about Ractor.
See ticket [Feature #17100] to see the implementation details
and discussions.
[Feature #17100]
This commit does not complete the implementation. You can find
many bugs on using Ractor. Also the specification will be changed
so that this feature is experimental. You will see a warning when
you make the first Ractor with `Ractor.new`.
I hope this feature can help programmers from thread-safety issues.
A prerequisite to fix https://bugs.ruby-lang.org/issues/15589 with JIT.
This commit alone doesn't make a significant difference yet, but I thought
this commit should be committed independently.
This method override was discussed in [Misc #16961].
