diff options
Diffstat (limited to 'doc/NEWS')
| -rw-r--r-- | doc/NEWS/NEWS-3.0.0.md | 12 | ||||
| -rw-r--r-- | doc/NEWS/NEWS-3.2.0.md | 820 | ||||
| -rw-r--r-- | doc/NEWS/NEWS-3.3.0.md | 529 |
3 files changed, 1361 insertions, 0 deletions
diff --git a/doc/NEWS/NEWS-3.0.0.md b/doc/NEWS/NEWS-3.0.0.md index 00c26fe585..bdbd47327b 100644 --- a/doc/NEWS/NEWS-3.0.0.md +++ b/doc/NEWS/NEWS-3.0.0.md @@ -512,6 +512,18 @@ Outstanding ones only. * This version is Ractor compatible. +* URI + + * URI.escape and URI.unescape have been removed. + Instead, use the following methods depending on your specific use case. + + * CGI.escape + * URI.encode_www_form + * URI.encode_www_form_component + * CGI.unescape + * URI.decode_www_form + * URI.decode_www_form_component + ## Compatibility issues Excluding feature bug fixes. diff --git a/doc/NEWS/NEWS-3.2.0.md b/doc/NEWS/NEWS-3.2.0.md new file mode 100644 index 0000000000..33a7b85c47 --- /dev/null +++ b/doc/NEWS/NEWS-3.2.0.md @@ -0,0 +1,820 @@ +# NEWS for Ruby 3.2.0 + +This document is a list of user-visible feature changes +since the **3.1.0** release, except for bug fixes. + +Note that each entry is kept to a minimum, see links for details. + +## Language changes + +* Anonymous rest and keyword rest arguments can now be passed as + arguments, instead of just used in method parameters. + [[Feature #18351]] + + ```ruby + def foo(*) + bar(*) + end + def baz(**) + quux(**) + end + ``` + +* A proc that accepts a single positional argument and keywords will + no longer autosplat. [[Bug #18633]] + + ```ruby + proc{|a, **k| a}.call([1, 2]) + # Ruby 3.1 and before + # => 1 + # Ruby 3.2 and after + # => [1, 2] + ``` + +* Constant assignment evaluation order for constants set on explicit + objects has been made consistent with single attribute assignment + evaluation order. With this code: + + ```ruby + foo::BAR = baz + ``` + + `foo` is now called before `baz`. Similarly, for multiple assignments + to constants, left-to-right evaluation order is used. With this + code: + + ```ruby + foo1::BAR1, foo2::BAR2 = baz1, baz2 + ``` + + The following evaluation order is now used: + + 1. `foo1` + 2. `foo2` + 3. `baz1` + 4. `baz2` + + [[Bug #15928]] + +* "Find pattern" is no longer experimental. + [[Feature #18585]] + +* Methods taking a rest parameter (like `*args`) and wishing to delegate keyword + arguments through `foo(*args)` must now be marked with `ruby2_keywords` + (if not already the case). In other words, all methods wishing to delegate + keyword arguments through `*args` must now be marked with `ruby2_keywords`, + with no exception. This will make it easier to transition to other ways of + delegation once a library can require Ruby 3+. Previously, the `ruby2_keywords` + flag was kept if the receiving method took `*args`, but this was a bug and an + inconsistency. A good technique to find the potentially-missing `ruby2_keywords` + is to run the test suite, for where it fails find the last method which must + receive keyword arguments, use `puts nil, caller, nil` there, and check each + method/block on the call chain which must delegate keywords is correctly marked + as `ruby2_keywords`. [[Bug #18625]] [[Bug #16466]] + + ```ruby + def target(**kw) + end + + # Accidentally worked without ruby2_keywords in Ruby 2.7-3.1, ruby2_keywords + # needed in 3.2+. Just like (*args, **kwargs) or (...) would be needed on + # both #foo and #bar when migrating away from ruby2_keywords. + ruby2_keywords def bar(*args) + target(*args) + end + + ruby2_keywords def foo(*args) + bar(*args) + end + + foo(k: 1) + ``` + +## Core classes updates + +Note: We're only listing outstanding class updates. + +* Fiber + + * Introduce Fiber.[] and Fiber.[]= for inheritable fiber storage. + Introduce Fiber#storage and Fiber#storage= (experimental) for + getting and resetting the current storage. Introduce + `Fiber.new(storage:)` for setting the storage when creating a + fiber. [[Feature #19078]] + + Existing Thread and Fiber local variables can be tricky to use. + Thread-local variables are shared between all fibers, making it + hard to isolate, while Fiber-local variables can be hard to + share. It is often desirable to define unit of execution + ("execution context") such that some state is shared between all + fibers and threads created in that context. This is what Fiber + storage provides. + + ```ruby + def log(message) + puts "#{Fiber[:request_id]}: #{message}" + end + + def handle_requests + while request = read_request + Fiber.schedule do + Fiber[:request_id] = SecureRandom.uuid + + request.messages.each do |message| + Fiber.schedule do + log("Handling #{message}") # Log includes inherited request_id. + end + end + end + end + end + ``` + + You should generally consider Fiber storage for any state which + you want to be shared implicitly between all fibers and threads + created in a given context, e.g. a connection pool, a request + id, a logger level, environment variables, configuration, etc. + +* Fiber::Scheduler + + * Introduce `Fiber::Scheduler#io_select` for non-blocking IO.select. + [[Feature #19060]] + +* IO + + * Introduce IO#timeout= and IO#timeout which can cause + IO::TimeoutError to be raised if a blocking operation exceeds the + specified timeout. [[Feature #18630]] + + ```ruby + STDIN.timeout = 1 + STDIN.read # => Blocking operation timed out! (IO::TimeoutError) + ``` + + * Introduce `IO.new(..., path:)` and promote `File#path` to `IO#path`. + [[Feature #19036]] + +* Class + + * Class#attached_object, which returns the object for which + the receiver is the singleton class. Raises TypeError if the + receiver is not a singleton class. + [[Feature #12084]] + + ```ruby + class Foo; end + + Foo.singleton_class.attached_object #=> Foo + Foo.new.singleton_class.attached_object #=> #<Foo:0x000000010491a370> + Foo.attached_object #=> TypeError: `Foo' is not a singleton class + nil.singleton_class.attached_object #=> TypeError: `NilClass' is not a singleton class + ``` + +* Data + + * New core class to represent simple immutable value object. The class is + similar to Struct and partially shares an implementation, but has more + lean and strict API. [[Feature #16122]] + + ```ruby + Measure = Data.define(:amount, :unit) + distance = Measure.new(100, 'km') #=> #<data Measure amount=100, unit="km"> + weight = Measure.new(amount: 50, unit: 'kg') #=> #<data Measure amount=50, unit="kg"> + weight.with(amount: 40) #=> #<data Measure amount=40, unit="kg"> + weight.amount #=> 50 + weight.amount = 40 #=> NoMethodError: undefined method `amount=' + ``` + +* Encoding + + * Encoding#replicate has been deprecated and will be removed in 3.3. [[Feature #18949]] + * The dummy `Encoding::UTF_16` and `Encoding::UTF_32` encodings no longer + try to dynamically guess the endian based on a byte order mark. + Use `Encoding::UTF_16BE`/`UTF_16LE` and `Encoding::UTF_32BE`/`UTF_32LE` instead. + This change speeds up getting the encoding of a String. [[Feature #18949]] + * Limit maximum encoding set size by 256. + If exceeding maximum size, `EncodingError` will be raised. [[Feature #18949]] + +* Enumerator + + * Enumerator.product has been added. Enumerator::Product is the implementation. [[Feature #18685]] + +* Exception + + * Exception#detailed_message has been added. + The default error printer calls this method on the Exception object + instead of #message. [[Feature #18564]] + +* Hash + + * Hash#shift now always returns nil if the hash is + empty, instead of returning the default value or + calling the default proc. [[Bug #16908]] + +* Integer + + * Integer#ceildiv has been added. [[Feature #18809]] + +* Kernel + + * Kernel#binding raises RuntimeError if called from a non-Ruby frame + (such as a method defined in C). [[Bug #18487]] + +* MatchData + + * MatchData#byteoffset has been added. [[Feature #13110]] + * MatchData#deconstruct has been added. [[Feature #18821]] + * MatchData#deconstruct_keys has been added. [[Feature #18821]] + +* Module + + * Module.used_refinements has been added. [[Feature #14332]] + * Module#refinements has been added. [[Feature #12737]] + * Module#const_added has been added. [[Feature #17881]] + * Module#undefined_instance_methods has been added. [[Feature #12655]] + +* Proc + + * Proc#dup returns an instance of subclass. [[Bug #17545]] + * Proc#parameters now accepts lambda keyword. [[Feature #15357]] + +* Process + * Added `RLIMIT_NPTS` constant to FreeBSD platform + +* Regexp + + * The cache-based optimization is introduced. + Many (but not all) Regexp matching is now in linear time, which + will prevent regular expression denial of service (ReDoS) + vulnerability. [[Feature #19104]] + + * Regexp.linear_time? is introduced. [[Feature #19194]] + + * Regexp.new now supports passing the regexp flags not only as an Integer, + but also as a String. Unknown flags raise ArgumentError. + Otherwise, anything other than `true`, `false`, `nil` or Integer will be warned. + [[Feature #18788]] + + * Regexp.timeout= has been added. Also, Regexp.new new supports timeout keyword. + See [[Feature #17837]] + +* Refinement + + * Refinement#refined_class has been added. [[Feature #12737]] + +* RubyVM::AbstractSyntaxTree + + * Add `error_tolerant` option for `parse`, `parse_file` and `of`. [[Feature #19013]] + With this option + + 1. SyntaxError is suppressed + 2. AST is returned for invalid input + 3. `end` is complemented when a parser reaches to the end of input but `end` is insufficient + 4. `end` is treated as keyword based on indent + + ```ruby + # Without error_tolerant option + root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY) + def m + a = 10 + if + end + RUBY + # => <internal:ast>:33:in `parse': syntax error, unexpected `end' (SyntaxError) + + # With error_tolerant option + root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY, error_tolerant: true) + def m + a = 10 + if + end + RUBY + p root # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-4:3> + + # `end` is treated as keyword based on indent + root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY, error_tolerant: true) + module Z + class Foo + foo. + end + + def bar + end + end + RUBY + p root.children[-1].children[-1].children[-1].children[-2..-1] + # => [#<RubyVM::AbstractSyntaxTree::Node:CLASS@2:2-4:5>, #<RubyVM::AbstractSyntaxTree::Node:DEFN@6:2-7:5>] + ``` + + * Add `keep_tokens` option for `parse`, `parse_file` and `of`. Add `#tokens` and `#all_tokens` + for RubyVM::AbstractSyntaxTree::Node [[Feature #19070]] + + ```ruby + root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2", keep_tokens: true) + root.tokens # => [[0, :tIDENTIFIER, "x", [1, 0, 1, 1]], [1, :tSP, " ", [1, 1, 1, 2]], ...] + root.tokens.map{_1[2]}.join # => "x = 1 + 2" + ``` + +* Set + + * Set is now available as a built-in class without the need for `require "set"`. [[Feature #16989]] + It is currently autoloaded via the Set constant or a call to Enumerable#to_set. + +* String + + * String#byteindex and String#byterindex have been added. [[Feature #13110]] + * Update Unicode to Version 15.0.0 and Emoji Version 15.0. [[Feature #18639]] + (also applies to Regexp) + * String#bytesplice has been added. [[Feature #18598]] + * String#dedup has been added as an alias to String#-@. [[Feature #18595]] + +* Struct + + * A Struct class can also be initialized with keyword arguments + without `keyword_init: true` on Struct.new [[Feature #16806]] + + ```ruby + Post = Struct.new(:id, :name) + Post.new(1, "hello") #=> #<struct Post id=1, name="hello"> + # From Ruby 3.2, the following code also works without keyword_init: true. + Post.new(id: 1, name: "hello") #=> #<struct Post id=1, name="hello"> + ``` + +* Thread + + * Thread.each_caller_location is added. [[Feature #16663]] + +* Thread::Queue + + * Thread::Queue#pop(timeout: sec) is added. [[Feature #18774]] + +* Thread::SizedQueue + + * Thread::SizedQueue#pop(timeout: sec) is added. [[Feature #18774]] + * Thread::SizedQueue#push(timeout: sec) is added. [[Feature #18944]] + +* Time + + * Time#deconstruct_keys is added, allowing to use Time instances + in pattern-matching expressions [[Feature #19071]] + + * Time.new now can parse a string like generated by Time#inspect + and return a Time instance based on the given argument. + [[Feature #18033]] + +* SyntaxError + * SyntaxError#path has been added. [[Feature #19138]] + +* TracePoint + + * TracePoint#binding now returns `nil` for `c_call`/`c_return` TracePoints. + [[Bug #18487]] + * TracePoint#enable `target_thread` keyword argument now defaults to the + current thread if a block is given and `target` and `target_line` keyword + arguments are not passed. [[Bug #16889]] + +* UnboundMethod + + * `UnboundMethod#==` returns `true` if the actual method is same. For example, + `String.instance_method(:object_id) == Array.instance_method(:object_id)` + returns `true`. [[Feature #18798]] + + * `UnboundMethod#inspect` does not show the receiver of `instance_method`. + For example `String.instance_method(:object_id).inspect` returns + `"#<UnboundMethod: Kernel#object_id()>"` + (was `"#<UnboundMethod: String(Kernel)#object_id()>"`). + +* GC + + * Expose `need_major_gc` via `GC.latest_gc_info`. [GH-6791] + +* ObjectSpace + + * `ObjectSpace.dump_all` dump shapes as well. [GH-6868] + +## Stdlib updates + +* Bundler + + * Bundler now uses [PubGrub] resolver instead of [Molinillo] for performance improvement. + * Add --ext=rust support to bundle gem for creating simple gems with Rust extensions. + [[GH-rubygems-6149]] + * Make cloning git repos faster [[GH-rubygems-4475]] + +* RubyGems + + * Add mswin support for cargo builder. [[GH-rubygems-6167]] + +* CGI + + * `CGI.escapeURIComponent` and `CGI.unescapeURIComponent` are added. + [[Feature #18822]] + +* Coverage + + * `Coverage.setup` now accepts `eval: true`. By this, `eval` and related methods are + able to generate code coverage. [[Feature #19008]] + + * `Coverage.supported?(mode)` enables detection of what coverage modes are + supported. [[Feature #19026]] + +* Date + + * Added `Date#deconstruct_keys` and `DateTime#deconstruct_keys` same as [[Feature #19071]] + +* ERB + + * `ERB::Util.html_escape` is made faster than `CGI.escapeHTML`. + * It no longer allocates a String object when no character needs to be escaped. + * It skips calling `#to_s` method when an argument is already a String. + * `ERB::Escape.html_escape` is added as an alias to `ERB::Util.html_escape`, + which has not been monkey-patched by Rails. + * `ERB::Util.url_encode` is made faster using `CGI.escapeURIComponent`. + * `-S` option is removed from `erb` command. + +* FileUtils + + * Add FileUtils.ln_sr method and `relative:` option to FileUtils.ln_s. + [[Feature #18925]] + +* IRB + + * debug.gem integration commands have been added: `debug`, `break`, `catch`, + `next`, `delete`, `step`, `continue`, `finish`, `backtrace`, `info` + * They work even if you don't have `gem "debug"` in your Gemfile. + * See also: [What's new in Ruby 3.2's IRB?](https://st0012.dev/whats-new-in-ruby-3-2-irb) + * More Pry-like commands and features have been added. + * `edit` and `show_cmds` (like Pry's `help`) are added. + * `ls` takes `-g` or `-G` option to filter out outputs. + * `show_source` is aliased from `$` and accepts unquoted inputs. + * `whereami` is aliased from `@`. + +* Net::Protocol + + * Improve `Net::BufferedIO` performance. [[GH-net-protocol-14]] + +* Pathname + + * Added `Pathname#lutime`. [[GH-pathname-20]] + +* Socket + + * Added the following constants for supported platforms. + * `SO_INCOMING_CPU` + * `SO_INCOMING_NAPI_ID` + * `SO_RTABLE` + * `SO_SETFIB` + * `SO_USER_COOKIE` + * `TCP_KEEPALIVE` + * `TCP_CONNECTION_INFO` + +* SyntaxSuggest + + * The feature of `syntax_suggest` formerly `dead_end` is integrated in Ruby. + [[Feature #18159]] + +* UNIXSocket + + * Add support for UNIXSocket on Windows. Emulate anonymous sockets. Add + support for File.socket? and File::Stat#socket? where possible. + [[Feature #19135]] + +* The following default gems are updated. + + * RubyGems 3.4.1 + * abbrev 0.1.1 + * benchmark 0.2.1 + * bigdecimal 3.1.3 + * bundler 2.4.1 + * cgi 0.3.6 + * csv 3.2.6 + * date 3.3.3 + * delegate 0.3.0 + * did_you_mean 1.6.3 + * digest 3.1.1 + * drb 2.1.1 + * english 0.7.2 + * erb 4.0.2 + * error_highlight 0.5.1 + * etc 1.4.2 + * fcntl 1.0.2 + * fiddle 1.1.1 + * fileutils 1.7.0 + * forwardable 1.3.3 + * getoptlong 0.2.0 + * io-console 0.6.0 + * io-nonblock 0.2.0 + * io-wait 0.3.0 + * ipaddr 1.2.5 + * irb 1.6.2 + * json 2.6.3 + * logger 1.5.3 + * mutex_m 0.1.2 + * net-http 0.3.2 + * net-protocol 0.2.1 + * nkf 0.1.2 + * open-uri 0.3.0 + * open3 0.1.2 + * openssl 3.1.0 + * optparse 0.3.1 + * ostruct 0.5.5 + * pathname 0.2.1 + * pp 0.4.0 + * pstore 0.1.2 + * psych 5.0.1 + * racc 1.6.2 + * rdoc 6.5.0 + * readline-ext 0.1.5 + * reline 0.3.2 + * resolv 0.2.2 + * resolv-replace 0.1.1 + * securerandom 0.2.2 + * set 1.0.3 + * stringio 3.0.4 + * strscan 3.0.5 + * syntax_suggest 1.0.2 + * syslog 0.1.1 + * tempfile 0.1.3 + * time 0.2.1 + * timeout 0.3.1 + * tmpdir 0.1.3 + * tsort 0.1.1 + * un 0.2.1 + * uri 0.12.0 + * weakref 0.1.2 + * win32ole 1.8.9 + * yaml 0.2.1 + * zlib 3.0.0 + +* The following bundled gems are updated. + + * minitest 5.16.3 + * power_assert 2.0.3 + * test-unit 3.5.7 + * net-ftp 0.2.0 + * net-imap 0.3.4 + * net-pop 0.1.2 + * net-smtp 0.3.3 + * rbs 2.8.2 + * typeprof 0.21.3 + * debug 1.7.1 + +See GitHub releases like [GitHub Releases of Logger](https://github.com/ruby/logger/releases) or changelog for details of the default gems or bundled gems. + +## Supported platforms + +* WebAssembly/WASI is added. See [wasm/README.md] and [ruby.wasm] for more details. [[Feature #18462]] + +## Compatibility issues + +* `String#to_c` currently treat a sequence of underscores as an end of Complex + string. [[Bug #19087]] + +* Now `ENV.clone` raises `TypeError` as well as `ENV.dup` [[Bug #17767]] + +### Removed constants + +The following deprecated constants are removed. + +* `Fixnum` and `Bignum` [[Feature #12005]] +* `Random::DEFAULT` [[Feature #17351]] +* `Struct::Group` +* `Struct::Passwd` + +### Removed methods + +The following deprecated methods are removed. + +* `Dir.exists?` [[Feature #17391]] +* `File.exists?` [[Feature #17391]] +* `Kernel#=~` [[Feature #15231]] +* `Kernel#taint`, `Kernel#untaint`, `Kernel#tainted?` + [[Feature #16131]] +* `Kernel#trust`, `Kernel#untrust`, `Kernel#untrusted?` + [[Feature #16131]] +* `Method#public?`, `Method#private?`, `Method#protected?`, + `UnboundMethod#public?`, `UnboundMethod#private?`, `UnboundMethod#protected?` + [[Bug #18729]] [[Bug #18751]] [[Bug #18435]] + +### Source code incompatibility of extension libraries + +* Extension libraries provide PRNG, subclasses of Random, need updates. + See [PRNG update] below for more information. [[Bug #19100]] + +### Error printer + +* Ruby no longer escapes control characters and backslashes in an + error message. [[Feature #18367]] + +### Constant lookup when defining a class/module + +* When defining a class/module directly under the Object class by class/module + statement, if there is already a class/module defined by `Module#include` + with the same name, the statement was handled as "open class" in Ruby 3.1 or before. + Since Ruby 3.2, a new class is defined instead. [[Feature #18832]] + +## Stdlib compatibility issues + +* Psych no longer bundles libyaml sources. + And also Fiddle no longer bundles libffi sources. + Users need to install the libyaml/libffi library themselves via the package + manager like apt, yum, brew, etc. + + Psych and fiddle supported the static build with specific version of libyaml + and libffi sources. You can build psych with libyaml-0.2.5 like this. + + ```bash + $ ./configure --with-libyaml-source-dir=/path/to/libyaml-0.2.5 + ``` + + And you can build fiddle with libffi-3.4.4 like this. + + ```bash + $ ./configure --with-libffi-source-dir=/path/to/libffi-3.4.4 + ``` + + [[Feature #18571]] + +* Check cookie name/path/domain characters in `CGI::Cookie`. [[CVE-2021-33621]] + +* `URI.parse` return empty string in host instead of nil. [[sec-156615]] + +## C API updates + +### Updated C APIs + +The following APIs are updated. + +* PRNG update + + `rb_random_interface_t` in ruby/random.h updated and versioned. + Extension libraries which use this interface and built for older + versions need to rebuild with adding `init_int32` function. + +### Added C APIs + +* `VALUE rb_hash_new_capa(long capa)` was added to created hashes with the desired capacity. +* `rb_internal_thread_add_event_hook` and `rb_internal_thread_add_event_hook` were added to instrument threads scheduling. + The following events are available: + * `RUBY_INTERNAL_THREAD_EVENT_STARTED` + * `RUBY_INTERNAL_THREAD_EVENT_READY` + * `RUBY_INTERNAL_THREAD_EVENT_RESUMED` + * `RUBY_INTERNAL_THREAD_EVENT_SUSPENDED` + * `RUBY_INTERNAL_THREAD_EVENT_EXITED` +* `rb_debug_inspector_current_depth` and `rb_debug_inspector_frame_depth` are added for debuggers. + +### Removed C APIs + +The following deprecated APIs are removed. + +* `rb_cData` variable. +* "taintedness" and "trustedness" functions. [[Feature #16131]] + +## Implementation improvements + +* Fixed several race conditions in Kernel#autoload. [[Bug #18782]] +* Cache invalidation for expressions referencing constants is now + more fine-grained. `RubyVM.stat(:global_constant_state)` was + removed because it was closely tied to the previous caching scheme + where setting any constant invalidates all caches in the system. + New keys, `:constant_cache_invalidations` and `:constant_cache_misses`, + were introduced to help with use cases for `:global_constant_state`. + [[Feature #18589]] +* The cache-based optimization for Regexp matching is introduced. + [[Feature #19104]] +* [Variable Width Allocation](https://shopify.engineering/ruby-variable-width-allocation) + is now enabled by default. [[Feature #18239]] +* Added a new instance variable caching mechanism, called object shapes, which + improves inline cache hits for most objects and allows us to generate very + efficient JIT code. Objects whose instance variables are defined in a + consistent order will see the most performance benefits. + [[Feature #18776]] +* Speed up marking instruction sequences by using a bitmap to find "markable" + objects. This change results in faster major collections. + [[Feature #18875]] + +## JIT + +### YJIT + +* YJIT is no longer experimental + * Has been tested on production workloads for over a year and proven to be quite stable. +* YJIT now supports both x86-64 and arm64/aarch64 CPUs on Linux, MacOS, BSD and other UNIX platforms. + * This release brings support for Mac M1/M2, AWS Graviton and Raspberry Pi 4. +* Building YJIT now requires Rust 1.58.0+. [[Feature #18481]] + * In order to ensure that CRuby is built with YJIT, please install `rustc` >= 1.58.0 + before running `./configure` + * Please reach out to the YJIT team should you run into any issues. +* Physical memory for JIT code is lazily allocated. Unlike Ruby 3.1, + the RSS of a Ruby process is minimized because virtual memory pages + allocated by `--yjit-exec-mem-size` will not be mapped to physical + memory pages until actually utilized by JIT code. +* Introduce Code GC that frees all code pages when the memory consumption + by JIT code reaches `--yjit-exec-mem-size`. + * `RubyVM::YJIT.runtime_stats` returns Code GC metrics in addition to + existing `inline_code_size` and `outlined_code_size` keys: + `code_gc_count`, `live_page_count`, `freed_page_count`, and `freed_code_size`. +* Most of the statistics produced by `RubyVM::YJIT.runtime_stats` are now available in release builds. + * Simply run ruby with `--yjit-stats` to compute and dump stats (incurs some run-time overhead). +* YJIT is now optimized to take advantage of object shapes. [[Feature #18776]] +* Take advantage of finer-grained constant invalidation to invalidate less code when defining new constants. [[Feature #18589]] +* The default `--yjit-exec-mem-size` is changed to 64 (MiB). +* The default `--yjit-call-threshold` is changed to 30. + +### MJIT + +* The MJIT compiler is re-implemented in Ruby as `ruby_vm/mjit/compiler`. +* MJIT compiler is executed under a forked Ruby process instead of + doing it in a native thread called MJIT worker. [[Feature #18968]] + * As a result, Microsoft Visual Studio (MSWIN) is no longer supported. +* MinGW is no longer supported. [[Feature #18824]] +* Rename `--mjit-min-calls` to `--mjit-call-threshold`. +* Change default `--mjit-max-cache` back from 10000 to 100. + +[Feature #12005]: https://bugs.ruby-lang.org/issues/12005 +[Feature #12084]: https://bugs.ruby-lang.org/issues/12084 +[Feature #12655]: https://bugs.ruby-lang.org/issues/12655 +[Feature #12737]: https://bugs.ruby-lang.org/issues/12737 +[Feature #13110]: https://bugs.ruby-lang.org/issues/13110 +[Feature #14332]: https://bugs.ruby-lang.org/issues/14332 +[Feature #15231]: https://bugs.ruby-lang.org/issues/15231 +[Feature #15357]: https://bugs.ruby-lang.org/issues/15357 +[Bug #15928]: https://bugs.ruby-lang.org/issues/15928 +[Feature #16122]: https://bugs.ruby-lang.org/issues/16122 +[Feature #16131]: https://bugs.ruby-lang.org/issues/16131 +[Bug #16466]: https://bugs.ruby-lang.org/issues/16466 +[Feature #16663]: https://bugs.ruby-lang.org/issues/16663 +[Feature #16806]: https://bugs.ruby-lang.org/issues/16806 +[Bug #16889]: https://bugs.ruby-lang.org/issues/16889 +[Bug #16908]: https://bugs.ruby-lang.org/issues/16908 +[Feature #16989]: https://bugs.ruby-lang.org/issues/16989 +[Feature #17351]: https://bugs.ruby-lang.org/issues/17351 +[Feature #17391]: https://bugs.ruby-lang.org/issues/17391 +[Bug #17545]: https://bugs.ruby-lang.org/issues/17545 +[Bug #17767]: https://bugs.ruby-lang.org/issues/17767 +[Feature #17837]: https://bugs.ruby-lang.org/issues/17837 +[Feature #17881]: https://bugs.ruby-lang.org/issues/17881 +[Feature #18033]: https://bugs.ruby-lang.org/issues/18033 +[Feature #18159]: https://bugs.ruby-lang.org/issues/18159 +[Feature #18239]: https://bugs.ruby-lang.org/issues/18239#note-17 +[Feature #18351]: https://bugs.ruby-lang.org/issues/18351 +[Feature #18367]: https://bugs.ruby-lang.org/issues/18367 +[Bug #18435]: https://bugs.ruby-lang.org/issues/18435 +[Feature #18462]: https://bugs.ruby-lang.org/issues/18462 +[Feature #18481]: https://bugs.ruby-lang.org/issues/18481 +[Bug #18487]: https://bugs.ruby-lang.org/issues/18487 +[Feature #18564]: https://bugs.ruby-lang.org/issues/18564 +[Feature #18571]: https://bugs.ruby-lang.org/issues/18571 +[Feature #18585]: https://bugs.ruby-lang.org/issues/18585 +[Feature #18589]: https://bugs.ruby-lang.org/issues/18589 +[Feature #18595]: https://bugs.ruby-lang.org/issues/18595 +[Feature #18598]: https://bugs.ruby-lang.org/issues/18598 +[Bug #18625]: https://bugs.ruby-lang.org/issues/18625 +[Feature #18630]: https://bugs.ruby-lang.org/issues/18630 +[Bug #18633]: https://bugs.ruby-lang.org/issues/18633 +[Feature #18639]: https://bugs.ruby-lang.org/issues/18639 +[Feature #18685]: https://bugs.ruby-lang.org/issues/18685 +[Bug #18729]: https://bugs.ruby-lang.org/issues/18729 +[Bug #18751]: https://bugs.ruby-lang.org/issues/18751 +[Feature #18774]: https://bugs.ruby-lang.org/issues/18774 +[Feature #18776]: https://bugs.ruby-lang.org/issues/18776 +[Bug #18782]: https://bugs.ruby-lang.org/issues/18782 +[Feature #18788]: https://bugs.ruby-lang.org/issues/18788 +[Feature #18798]: https://bugs.ruby-lang.org/issues/18798 +[Feature #18809]: https://bugs.ruby-lang.org/issues/18809 +[Feature #18821]: https://bugs.ruby-lang.org/issues/18821 +[Feature #18822]: https://bugs.ruby-lang.org/issues/18822 +[Feature #18824]: https://bugs.ruby-lang.org/issues/18824 +[Feature #18832]: https://bugs.ruby-lang.org/issues/18832 +[Feature #18875]: https://bugs.ruby-lang.org/issues/18875 +[Feature #18925]: https://bugs.ruby-lang.org/issues/18925 +[Feature #18944]: https://bugs.ruby-lang.org/issues/18944 +[Feature #18949]: https://bugs.ruby-lang.org/issues/18949 +[Feature #18968]: https://bugs.ruby-lang.org/issues/18968 +[Feature #19008]: https://bugs.ruby-lang.org/issues/19008 +[Feature #19013]: https://bugs.ruby-lang.org/issues/19013 +[Feature #19026]: https://bugs.ruby-lang.org/issues/19026 +[Feature #19036]: https://bugs.ruby-lang.org/issues/19036 +[Feature #19060]: https://bugs.ruby-lang.org/issues/19060 +[Feature #19070]: https://bugs.ruby-lang.org/issues/19070 +[Feature #19071]: https://bugs.ruby-lang.org/issues/19071 +[Feature #19078]: https://bugs.ruby-lang.org/issues/19078 +[Bug #19087]: https://bugs.ruby-lang.org/issues/19087 +[Bug #19100]: https://bugs.ruby-lang.org/issues/19100 +[Feature #19104]: https://bugs.ruby-lang.org/issues/19104 +[Feature #19135]: https://bugs.ruby-lang.org/issues/19135 +[Feature #19138]: https://bugs.ruby-lang.org/issues/19138 +[Feature #19194]: https://bugs.ruby-lang.org/issues/19194 +[Molinillo]: https://github.com/CocoaPods/Molinillo +[PubGrub]: https://github.com/jhawthorn/pub_grub +[GH-net-protocol-14]: https://github.com/ruby/net-protocol/pull/14 +[GH-pathname-20]: https://github.com/ruby/pathname/pull/20 +[GH-6791]: https://github.com/ruby/ruby/pull/6791 +[GH-6868]: https://github.com/ruby/ruby/pull/6868 +[GH-rubygems-4475]: https://github.com/rubygems/rubygems/pull/4475 +[GH-rubygems-6149]: https://github.com/rubygems/rubygems/pull/6149 +[GH-rubygems-6167]: https://github.com/rubygems/rubygems/pull/6167 +[sec-156615]: https://hackerone.com/reports/156615 +[CVE-2021-33621]: https://www.ruby-lang.org/en/news/2022/11/22/http-response-splitting-in-cgi-cve-2021-33621/ +[wasm/README.md]: https://github.com/ruby/ruby/blob/master/wasm/README.md +[ruby.wasm]: https://github.com/ruby/ruby.wasm diff --git a/doc/NEWS/NEWS-3.3.0.md b/doc/NEWS/NEWS-3.3.0.md new file mode 100644 index 0000000000..364786d754 --- /dev/null +++ b/doc/NEWS/NEWS-3.3.0.md @@ -0,0 +1,529 @@ +# NEWS for Ruby 3.3.0 + +This document is a list of user-visible feature changes +since the **3.2.0** release, except for bug fixes. + +Note that each entry is kept to a minimum, see links for details. + +## Command line options + +* A new `performance` warning category was introduced. + They are not displayed by default even in verbose mode. + Turn them on with `-W:performance` or `Warning[:performance] = true`. [[Feature #19538]] + +* A new `RUBY_CRASH_REPORT` environment variable was introduced to allow + redirecting Ruby crash reports to a file or sub command. See the `BUG REPORT ENVIRONMENT` + section of the ruby manpage for further details. [[Feature #19790]] + +## Core classes updates + +Note: We're only listing outstanding class updates. + +* Array + + * Array#pack now raises ArgumentError for unknown directives. [[Bug #19150]] + +* Dir + + * Dir.for_fd added for returning a Dir object for the directory specified + by the provided directory file descriptor. [[Feature #19347]] + * Dir.fchdir added for changing the directory to the directory specified + by the provided directory file descriptor. [[Feature #19347]] + * Dir#chdir added for changing the directory to the directory specified by + the provided `Dir` object. [[Feature #19347]] + +* Encoding + + * `Encoding#replicate` has been removed, it was already deprecated. [[Feature #18949]] + +* Fiber + + * Introduce Fiber#kill. [[Bug #595]] + + ```ruby + fiber = Fiber.new do + while true + puts "Yielding..." + Fiber.yield + end + ensure + puts "Exiting..." + end + + fiber.resume + # Yielding... + fiber.kill + # Exiting... + ``` + +* MatchData + + * MatchData#named_captures now accepts optional `symbolize_names` + keyword. [[Feature #19591]] + +* Module + + * Module#set_temporary_name added for setting a temporary name for a + module. [[Feature #19521]] + +* ObjectSpace::WeakKeyMap + + * New core class to build collections with weak references. + The class use equality semantic to lookup keys like a regular hash, + but it doesn't hold strong references on the keys. [[Feature #18498]] + +* ObjectSpace::WeakMap + + * ObjectSpace::WeakMap#delete was added to eagerly clear weak map + entries. [[Feature #19561]] + +* Proc + * Now Proc#dup and Proc#clone call `#initialize_dup` and `#initialize_clone` + hooks respectively. [[Feature #19362]] + +* Process + + * New Process.warmup method that notify the Ruby virtual machine that the boot sequence is finished, + and that now is a good time to optimize the application. This is useful + for long-running applications. The actual optimizations performed are entirely + implementation-specific and may change in the future without notice. [[Feature #18885]] + +* Process::Status + + * Process::Status#& and Process::Status#>> are deprecated. [[Bug #19868]] + +* Range + + * Range#reverse_each can now process beginless ranges with an Integer endpoint. [[Feature #18515]] + * Range#reverse_each now raises TypeError for endless ranges. [[Feature #18551]] + * Range#overlap? added for checking if two ranges overlap. [[Feature #19839]] + +* Refinement + + * Add Refinement#target as an alternative of Refinement#refined_class. + Refinement#refined_class is deprecated and will be removed in Ruby + 3.4. [[Feature #19714]] + +* Regexp + + * The cache-based optimization now supports lookarounds and atomic groupings. That is, match + for Regexp containing these extensions can now also be performed in linear time to the length + of the input string. However, these cannot contain captures and cannot be nested. [[Feature #19725]] + +* String + + * String#unpack now raises ArgumentError for unknown directives. [[Bug #19150]] + * String#bytesplice now accepts new arguments index/length or range of the + source string to be copied. [[Feature #19314]] + +* Thread::Queue + + * Thread::Queue#freeze now raises TypeError. [[Bug #17146]] + +* Thread::SizedQueue + + * Thread::SizedQueue#freeze now raises TypeError. [[Bug #17146]] + +* Time + + * Time.new with a string argument became stricter. [[Bug #19293]] + + ```ruby + Time.new('2023-12-20') + # no time information (ArgumentError) + ``` + +* TracePoint + + * TracePoint supports `rescue` event. When the raised exception was rescued, + the TracePoint will fire the hook. `rescue` event only supports Ruby-level + `rescue`. [[Feature #19572]] + +## Stdlib updates + +* RubyGems and Bundler warn if users do `require` the following gems without adding them to Gemfile or gemspec. + This is because they will become the bundled gems in the future version of Ruby. This warning is suppressed + if you use bootsnap gem. We recommend to run your application with `DISABLE_BOOTSNAP=1` environmental variable + at least once. This is limitation of this version. + [[Feature #19351]] [[Feature #19776]] [[Feature #19843]] + * abbrev + * base64 + * bigdecimal + * csv + * drb + * getoptlong + * mutex_m + * nkf + * observer + * racc + * resolv-replace + * rinda + * syslog + +* Socket#recv and Socket#recv_nonblock returns `nil` instead of an empty string on closed + connections. Socket#recvmsg and Socket#recvmsg_nonblock returns `nil` instead of an empty packet on closed + connections. [[Bug #19012]] + +* Name resolution such as Socket.getaddrinfo, Socket.getnameinfo, Addrinfo.getaddrinfo, etc. + can now be interrupted. [[Feature #19965]] + +* Random::Formatter#alphanumeric is extended to accept optional `chars` + keyword argument. [[Feature #18183]] + +The following default gem is added. + +* prism 0.19.0 + +The following default gems are updated. + +* RubyGems 3.5.3 +* abbrev 0.1.2 +* base64 0.2.0 +* benchmark 0.3.0 +* bigdecimal 3.1.5 +* bundler 2.5.3 +* cgi 0.4.1 +* csv 3.2.8 +* date 3.3.4 +* delegate 0.3.1 +* drb 2.2.0 +* english 0.8.0 +* erb 4.0.3 +* error_highlight 0.6.0 +* etc 1.4.3 +* fcntl 1.1.0 +* fiddle 1.1.2 +* fileutils 1.7.2 +* find 0.2.0 +* getoptlong 0.2.1 +* io-console 0.7.1 +* io-nonblock 0.3.0 +* io-wait 0.3.1 +* ipaddr 1.2.6 +* irb 1.11.0 +* json 2.7.1 +* logger 1.6.0 +* mutex_m 0.2.0 +* net-http 0.4.0 +* net-protocol 0.2.2 +* nkf 0.1.3 +* observer 0.1.2 +* open-uri 0.4.1 +* open3 0.2.1 +* openssl 3.2.0 +* optparse 0.4.0 +* ostruct 0.6.0 +* pathname 0.3.0 +* pp 0.5.0 +* prettyprint 0.2.0 +* pstore 0.1.3 +* psych 5.1.2 +* rdoc 6.6.2 +* readline 0.0.4 +* reline 0.4.1 +* resolv 0.3.0 +* rinda 0.2.0 +* securerandom 0.3.1 +* set 1.1.0 +* shellwords 0.2.0 +* singleton 0.2.0 +* stringio 3.1.0 +* strscan 3.0.7 +* syntax_suggest 2.0.0 +* syslog 0.1.2 +* tempfile 0.2.1 +* time 0.3.0 +* timeout 0.4.1 +* tmpdir 0.2.0 +* tsort 0.2.0 +* un 0.3.0 +* uri 0.13.0 +* weakref 0.1.3 +* win32ole 1.8.10 +* yaml 0.3.0 +* zlib 3.1.0 + +The following bundled gem is promoted from default gems. + +* racc 1.7.3 + +The following bundled gems are updated. + +* minitest 5.20.0 +* rake 13.1.0 +* test-unit 3.6.1 +* rexml 3.2.6 +* rss 0.3.0 +* net-ftp 0.3.3 +* net-imap 0.4.9 +* net-smtp 0.4.0 +* rbs 3.4.0 +* typeprof 0.21.9 +* debug 1.9.1 + +See GitHub releases like [Logger](https://github.com/ruby/logger/releases) or +changelog for details of the default gems or bundled gems. + +### Prism + +* Introduced [the Prism parser](https://github.com/ruby/prism) as a default gem + * Prism is a portable, error tolerant, and maintainable recursive descent parser for the Ruby language +* Prism is production ready and actively maintained, you can use it in place of Ripper + * There is [extensive documentation](https://ruby.github.io/prism/) on how to use Prism + * Prism is both a C library that will be used internally by CRuby and a Ruby gem that can be used by any tooling which needs to parse Ruby code + * Notable methods in the Prism API are: + * `Prism.parse(source)` which returns the AST as part of a parse result object + * `Prism.parse_comments(source)` which returns the comments + * `Prism.parse_success?(source)` which returns true if there are no errors +* You can make pull requests or issues directly on [the Prism repository](https://github.com/ruby/prism) if you are interested in contributing +* You can now use `ruby --parser=prism` or `RUBYOPT="--parser=prism"` to experiment with the Prism compiler. Please note that this flag is for debugging only. + +## Compatibility issues + +* Subprocess creation/forking via the following file open methods is deprecated. [[Feature #19630]] + * Kernel#open + * URI.open + * IO.binread + * IO.foreach + * IO.readlines + * IO.read + * IO.write + +* When given a non-lambda, non-literal block, Kernel#lambda with now raises + ArgumentError instead of returning it unmodified. These usages have been + issuing warnings under the `Warning[:deprecated]` category since Ruby 3.0.0. + [[Feature #19777]] + +* The `RUBY_GC_HEAP_INIT_SLOTS` environment variable has been deprecated and + removed. Environment variables `RUBY_GC_HEAP_%d_INIT_SLOTS` should be + used instead. [[Feature #19785]] + +* `it` calls without arguments in a block with no ordinary parameters are + deprecated. `it` will be a reference to the first block parameter in Ruby 3.4. + [[Feature #18980]] + +* Error message for NoMethodError have changed to not use the target object's `#inspect` + for efficiency, and says "instance of ClassName" instead. [[Feature #18285]] + + ```ruby + ([1] * 100).nonexisting + # undefined method `nonexisting' for an instance of Array (NoMethodError) + ``` + +* Now anonymous parameters forwarding is disallowed inside a block + that uses anonymous parameters. [[Feature #19370]] + +## Stdlib compatibility issues + +* `racc` is promoted to bundled gems. + * You need to add `racc` to your `Gemfile` if you use `racc` under bundler environment. +* `ext/readline` is retired + * We have `reline` that is pure Ruby implementation compatible with `ext/readline` API. + We rely on `reline` in the future. If you need to use `ext/readline`, you can install + `ext/readline` via rubygems.org with `gem install readline-ext`. + * We no longer need to install libraries like `libreadline` or `libedit`. + +## C API updates + +* `rb_postponed_job` updates + * New APIs and deprecated APIs (see comments for details) + * added: `rb_postponed_job_preregister()` + * added: `rb_postponed_job_trigger()` + * deprecated: `rb_postponed_job_register()` (and semantic change. see below) + * deprecated: `rb_postponed_job_register_one()` + * The postponed job APIs have been changed to address some rare crashes. + To solve the issue, we introduced new two APIs and deprecated current APIs. + The semantics of these functions have also changed slightly; `rb_postponed_job_register` + now behaves like the `once` variant in that multiple calls with the same + `func` might be coalesced into a single execution of the `func` + [[Feature #20057]] + +* Some updates for internal thread event hook APIs + * `rb_internal_thread_event_data_t` with a target Ruby thread (VALUE) + and callback functions (`rb_internal_thread_event_callback`) receive it. + https://github.com/ruby/ruby/pull/8885 + * The following functions are introduced to manipulate Ruby thread local data + from internal thread event hook APIs (they are introduced since Ruby 3.2). + https://github.com/ruby/ruby/pull/8936 + * `rb_internal_thread_specific_key_create()` + * `rb_internal_thread_specific_get()` + * `rb_internal_thread_specific_set()` + +* `rb_profile_thread_frames()` is introduced to get a frames from + a specific thread. + [[Feature #10602]] + +* `rb_data_define()` is introduced to define `Data`. [[Feature #19757]] + +* `rb_ext_resolve_symbol()` is introduced to search a function from + extension libraries. [[Feature #20005]] + +* IO related updates: + * The details of `rb_io_t` will be hidden and deprecated attributes + are added for each members. [[Feature #19057]] + * `rb_io_path(VALUE io)` is introduced to get a path of `io`. + * `rb_io_closed_p(VALUE io)` to get opening or closing of `io`. + * `rb_io_mode(VALUE io)` to get the mode of `io`. + * `rb_io_open_descriptor()` is introduced to make an IO object from a file + descriptor. + +## Implementation improvements + +### Parser + +* Replace Bison with [Lrama LALR parser generator](https://github.com/ruby/lrama). + No need to install Bison to build Ruby from source code anymore. + We will no longer suffer bison compatibility issues and we can use new features by just implementing it to Lrama. [[Feature #19637]] + * See [The future vision of Ruby Parser](https://rubykaigi.org/2023/presentations/spikeolaf.html) for detail. + * Lrama internal parser is a LR parser generated by Racc for maintainability. + * Parameterizing Rules `(?, *, +)` are supported, it will be used in Ruby parse.y. + +### GC / Memory management + +* Major performance improvements over Ruby 3.2 + * Young objects referenced by old objects are no longer immediately + promoted to the old generation. This significantly reduces the frequency of + major GC collections. [[Feature #19678]] + * A new `REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO` tuning variable was + introduced to control the number of unprotected objects cause a major GC + collection to trigger. The default is set to `0.01` (1%). This significantly + reduces the frequency of major GC collection. [[Feature #19571]] + * Write Barriers were implemented for many core types that were missing them, + notably `Time`, `Enumerator`, `MatchData`, `Method`, `File::Stat`, `BigDecimal` + and several others. This significantly reduces minor GC collection time and major + GC collection frequency. + * Most core classes are now using Variable Width Allocation, notably `Hash`, `Time`, + `Thread::Backtrace`, `Thread::Backtrace::Location`, `File::Stat`, `Method`. + This makes these classes faster to allocate and free, use less memory and reduce + heap fragmentation. +* `defined?(@ivar)` is optimized with Object Shapes. + +### YJIT + +* Major performance improvements over Ruby 3.2 + * Support for splat and rest arguments has been improved. + * Registers are allocated for stack operations of the virtual machine. + * More calls with optional arguments are compiled. Exception handlers are also compiled. + * Unsupported call types and megamorphic call sites no longer exit to the interpreter. + * Basic methods like Rails `#blank?` and + [specialized `#present?`](https://github.com/rails/rails/pull/49909) are inlined. + * `Integer#*`, `Integer#!=`, `String#!=`, `String#getbyte`, + `Kernel#block_given?`, `Kernel#is_a?`, `Kernel#instance_of?`, and `Module#===` + are specially optimized. + * Compilation speed is now slightly faster than Ruby 3.2. + * Now more than 3x faster than the interpreter on Optcarrot! +* Significantly improved memory usage over Ruby 3.2 + * Metadata for compiled code uses a lot less memory. + * `--yjit-call-threshold` is automatically raised from 30 to 120 + when the application has more than 40,000 ISEQs. + * `--yjit-cold-threshold` is added to skip compiling cold ISEQs. + * More compact code is generated on Arm64. +* Code GC is now disabled by default + * `--yjit-exec-mem-size` is treated as a hard limit where compilation of new code stops. + * No sudden drops in performance due to code GC. + Better copy-on-write behavior on servers reforking with + [Pitchfork](https://github.com/shopify/pitchfork). + * You can still enable code GC if desired with `--yjit-code-gc` +* Add `RubyVM::YJIT.enable` that can enable YJIT at run-time + * You can start YJIT without modifying command-line arguments or environment variables. + Rails 7.2 will [enable YJIT by default](https://github.com/rails/rails/pull/49947) + using this method. + * This can also be used to enable YJIT only once your application is + done booting. `--yjit-disable` can be used if you want to use other + YJIT options while disabling YJIT at boot. +* More YJIT stats are available by default + * `yjit_alloc_size` and several more metadata-related stats are now available by default. + * `ratio_in_yjit` stat produced by `--yjit-stats` is now available in release builds, + a special stats or dev build is no longer required to access most stats. +* Add more profiling capabilities + * `--yjit-perf` is added to facilitate profiling with Linux perf. + * `--yjit-trace-exits` now supports sampling with `--yjit-trace-exits-sample-rate=N` +* More thorough testing and multiple bug fixes +* `--yjit-stats=quiet` is added to avoid printing stats on exit. + +### MJIT + +* MJIT is removed. + * `--disable-jit-support` is removed. Consider using `--disable-yjit --disable-rjit` instead. + +### RJIT + +* Introduced a pure-Ruby JIT compiler RJIT. + * RJIT supports only x86\_64 architecture on Unix platforms. + * Unlike MJIT, it doesn't require a C compiler at runtime. +* RJIT exists only for experimental purposes. + * You should keep using YJIT in production. + +### M:N Thread scheduler + +* M:N Thread scheduler is introduced. [[Feature #19842]] + * Background: Ruby 1.8 and before, M:1 thread scheduler (M Ruby threads + with 1 native thread. Called as User level threads or Green threads) + is used. Ruby 1.9 and later, 1:1 thread scheduler (1 Ruby thread with + 1 native thread). M:1 threads takes lower resources compare with 1:1 + threads because it needs only 1 native threads. However it is difficult + to support context switching for all of blocking operation so 1:1 + threads are employed from Ruby 1.9. M:N thread scheduler uses N native + threads for M Ruby threads (N is small number in general). It doesn't + need same number of native threads as Ruby threads (similar to the M:1 + thread scheduler). Also our M:N threads supports blocking operations + well same as 1:1 threads. See the ticket for more details. + Our M:N thread scheduler refers on the goroutine scheduler in the + Go language. + * In a ractor, only 1 thread can run in a same time because of + implementation. Therefore, applications that use only one Ractor + (most applications) M:N thread scheduler works as M:1 thread scheduler + with further extension from Ruby 1.8. + * M:N thread scheduler can introduce incompatibility for C-extensions, + so it is disabled by default on the main Ractors. + `RUBY_MN_THREADS=1` environment variable will enable it. + On non-main Ractors, M:N thread scheduler is enabled (and can not + disable it now). + * `N` (the number of native threads) can be specified with `RUBY_MAX_CPU` + environment variable. The default is 8. + Note that more than `N` native threads are used to support many kind of + blocking operations. + +[Bug #595]: https://bugs.ruby-lang.org/issues/595 +[Feature #10602]: https://bugs.ruby-lang.org/issues/10602 +[Bug #17146]: https://bugs.ruby-lang.org/issues/17146 +[Feature #18183]: https://bugs.ruby-lang.org/issues/18183 +[Feature #18285]: https://bugs.ruby-lang.org/issues/18285 +[Feature #18498]: https://bugs.ruby-lang.org/issues/18498 +[Feature #18515]: https://bugs.ruby-lang.org/issues/18515 +[Feature #18551]: https://bugs.ruby-lang.org/issues/18551 +[Feature #18885]: https://bugs.ruby-lang.org/issues/18885 +[Feature #18949]: https://bugs.ruby-lang.org/issues/18949 +[Feature #18980]: https://bugs.ruby-lang.org/issues/18980 +[Bug #19012]: https://bugs.ruby-lang.org/issues/19012 +[Feature #19057]: https://bugs.ruby-lang.org/issues/19057 +[Bug #19150]: https://bugs.ruby-lang.org/issues/19150 +[Bug #19293]: https://bugs.ruby-lang.org/issues/19293 +[Feature #19314]: https://bugs.ruby-lang.org/issues/19314 +[Feature #19347]: https://bugs.ruby-lang.org/issues/19347 +[Feature #19351]: https://bugs.ruby-lang.org/issues/19351 +[Feature #19362]: https://bugs.ruby-lang.org/issues/19362 +[Feature #19370]: https://bugs.ruby-lang.org/issues/19370 +[Feature #19521]: https://bugs.ruby-lang.org/issues/19521 +[Feature #19538]: https://bugs.ruby-lang.org/issues/19538 +[Feature #19561]: https://bugs.ruby-lang.org/issues/19561 +[Feature #19571]: https://bugs.ruby-lang.org/issues/19571 +[Feature #19572]: https://bugs.ruby-lang.org/issues/19572 +[Feature #19591]: https://bugs.ruby-lang.org/issues/19591 +[Feature #19630]: https://bugs.ruby-lang.org/issues/19630 +[Feature #19637]: https://bugs.ruby-lang.org/issues/19637 +[Feature #19678]: https://bugs.ruby-lang.org/issues/19678 +[Feature #19714]: https://bugs.ruby-lang.org/issues/19714 +[Feature #19725]: https://bugs.ruby-lang.org/issues/19725 +[Feature #19757]: https://bugs.ruby-lang.org/issues/19757 +[Feature #19776]: https://bugs.ruby-lang.org/issues/19776 +[Feature #19777]: https://bugs.ruby-lang.org/issues/19777 +[Feature #19785]: https://bugs.ruby-lang.org/issues/19785 +[Feature #19790]: https://bugs.ruby-lang.org/issues/19790 +[Feature #19839]: https://bugs.ruby-lang.org/issues/19839 +[Feature #19842]: https://bugs.ruby-lang.org/issues/19842 +[Feature #19843]: https://bugs.ruby-lang.org/issues/19843 +[Bug #19868]: https://bugs.ruby-lang.org/issues/19868 +[Feature #19965]: https://bugs.ruby-lang.org/issues/19965 +[Feature #20005]: https://bugs.ruby-lang.org/issues/20005 +[Feature #20057]: https://bugs.ruby-lang.org/issues/20057 |