January 2025 - ruby-core - ml.ruby-lang.org

[ruby-core:115995] [Ruby master Bug#20112] Ractors not working properly in ruby 3.3.0
by ariasdiniz (Aria Diniz) 19 May '25

19 May '25

Issue #20112 has been reported by ariasdiniz (Aria Diniz). ---------------------------------------- Bug #20112: Ractors not working properly in ruby 3.3.0 https://bugs.ruby-lang.org/issues/20112 * Author: ariasdiniz (Aria Diniz) * Status: Open * Priority: Normal * ruby -v: 3.3.0 * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I recently installed Ruby 3.3.0, and noticed that some of my scripts that use Ractors started to struggle with performance. After doing some benchmarks, I noticed that, while Ractors seem to be working well on Ruby 3.2.2, they're not working properly on 3.3.0. I'm using Ubuntu 22.04.3 LTS Here is the benchmark code: ``` ruby # frozen_string_literal: true require 'benchmark' Ractor.new { :warmup } if defined?(Ractor) Benchmark.bmbm do |x| x.report("Thread: ") do threads = [] 8.times do |i| threads << Thread.new do 20000000.times do |j| ((i * 20000000) + j)**2 end end end threads.each(&:join) end x.report("Ractor: ") do ractors = [] 0..8.times do |i| ractors << Ractor.new(i) do |k| 20000000.times do |j| ((k * 20000000) + j)**2 end end end ractors.map(&:take) end end ``` Here is the results for Ruby 3.2.2: Rehearsal -------------------------------------------- Thread: 7.666909 0.001091 7.668000 ( 7.675266) Ractor: 19.318528 0.012017 19.330545 ( 2.505888) ---------------------------------- total: 26.998545sec user system total real Thread: 7.918141 0.004011 7.922152 ( 7.928772) Ractor: 19.366414 0.003954 19.370368 ( 2.517993) Here is the results for Ruby 3.3.0: Rehearsal -------------------------------------------- Thread: 8.634152 0.010895 8.645047 ( 8.645104) Ractor: 100.172179 0.035985 100.208164 ( 15.213245) --------------------------------- total: 108.853211sec user system total real Thread: 9.451236 0.004002 9.455238 ( 9.460132) Ractor: 118.463294 0.119942 118.583236 ( 18.462157) -- https://bugs.ruby-lang.org/

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[ruby-core:120671] [Ruby master Bug#21037] Ractors hang with multiple threads
by tenderlovemaking (Aaron Patterson) 14 May '25

14 May '25

Issue #21037 has been reported by tenderlovemaking (Aaron Patterson). ---------------------------------------- Bug #21037: Ractors hang with multiple threads https://bugs.ruby-lang.org/issues/21037 * Author: tenderlovemaking (Aaron Patterson) * Status: Open * ruby -v: ruby 3.5.0dev (2025-01-14T20:59:39Z master f1e32914eb) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- The following program hangs, but I don't expect it to hang: ```ruby # frozen_string_literal: true class Map def initialize @r = Ractor.new { cache = { "int" => "integer", "bool" => "boolean" } loop do key = receive Ractor.yield key end } freeze end def fetch(key) @r.send key m = @r.take raise unless key == m m end end tm = Map.new t1 = Thread.new { 10.times { |i| p [i + 1,tm.fetch("int")] } } t2 = Thread.new { 10.times { |i| p [i + 1, tm.fetch("bool")] } } t1.join t2.join ``` I'm not sure why this program hangs yet, but it does both on macOS and Linux. I've tested with master, Ruby 3.4, and Ruby 3.3. I'm not sure why it's hanging yet, but I wanted to file an issue. -- https://bugs.ruby-lang.org/

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[ruby-core:119137] [Ruby master Bug#20726] Issue with hash without braces when assigned to constant with ractor literals
by luke-gru (Luke Gruber) 14 May '25

14 May '25

Issue #20726 has been reported by luke-gru (Luke Gruber). ---------------------------------------- Bug #20726: Issue with hash without braces when assigned to constant with ractor literals https://bugs.ruby-lang.org/issues/20726 * Author: luke-gru (Luke Gruber) * Status: Open * ruby -v: 3.4.0dev * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- ```ruby a = 'hi' A = ['hello' => a] p A ``` gives: ``` ./ruby -I../ruby/lib -I. -I.ext/x86_64-linux -I.ext/common -r./x86_64-linux-fake ../ruby/test.rb -- raw disasm-------- trace: 1 0000 putchilledstring "hi" ( 3) 0002 setlocal_WC_0 3 ( 3) trace: 1 0004 newarray 1 ( 4) 0006 putspecialobject 3 ( 4) * 0008 setconstant :A ( 4) trace: 1 0010 putself ( 5) 0011 opt_getconstant_path [:A] ( 5) 0013 opt_send_without_block <calldata:p, 1> ( 5) 0015 leave ( 5) --------------------- ../ruby/test.rb:4: argument stack underflow (-1) ../ruby/test.rb: compile error (SyntaxError) ``` This is due to a line in `compile.c`, function `compile_shareable_literal_constant`: ```c if (!RNODE_HASH(node)->nd_brace) { } ``` I'm not sure why this condition is there so I'm not confident in making a fix. Also, my git-fu isn't the best so I can't track down the right commit where it was added. -- https://bugs.ruby-lang.org/

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[ruby-core:111809] [Ruby master Bug#19338] Ruby hangs when defining new constant in ractor
by luke-gru (Luke Gruber) 13 May '25

13 May '25

Issue #19338 has been reported by luke-gru (Luke Gruber). ---------------------------------------- Bug #19338: Ruby hangs when defining new constant in ractor https://bugs.ruby-lang.org/issues/19338 * Author: luke-gru (Luke Gruber) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- This code causes Ruby to hang: ``` ruby rs = [] 2.times do rs << Ractor.new do MYCONSTANT = 2 end end rs.each(&:take) ``` There is a problem when the warning is being outputted with multiple ractors. A thread is calling RB_VM_LOCK() while holding the VM lock in ractor.c (ractor_check_blocking()) If the code is changed to RB_VM_LOCK_ENTER() and RB_VM_LOCK_LEAVE() then it fixes it, but I don't know if there's a better way. Thanks! -- https://bugs.ruby-lang.org/

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[ruby-core:118467] [Ruby master Feature#20610] Float::INFINITY as IO.select timeout argument
by akr (Akira Tanaka) 13 May '25

13 May '25

Issue #20610 has been reported by akr (Akira Tanaka). ---------------------------------------- Feature #20610: Float::INFINITY as IO.select timeout argument https://bugs.ruby-lang.org/issues/20610 * Author: akr (Akira Tanaka) * Status: Open ---------------------------------------- I propose IO.select accepts Float::INFINITY as a timeout argument. It behaves the same as nil which means IO.select will block indefinitely. Motivation: Currently, the Ruby convention to indicate no timeout is using nil. This practice often forces us to treat the nil case separately. Conceptually, no timeout can be thought of as an infinite timeout. So I propose to accept Float::INFINITY as a timeout. It makes us less conditionals when we need to calculate or compare timeouts. Assume `now` method as follows to read the following examples. ``` def now = Process.clock_gettime(Process::CLOCK_MONOTONIC) ``` Example 1: absolute timeout Sometimes we maintain timeout as an absolute clock. The following method takes a relative timeout as an argument. It invokes IO.select several times and raises if the timeout is reached. Assuming a user must specify a finite timeout, the following definition is possible. ``` # user_timeout is the required argument def method(..., user_timeout) abs_timeout = now + user_timeout loop { IO.select(rs, ws, es, (abs_timeout - now).clamp(0..)) raise "timeout" if abs_timeout < now ... } end ``` Consider we need to make user_timeout optional. If user_timeout is not given, no timeout occurs. The implementation is as follows. I think the following implementation is typical. It needs 3 more conditionals than the above. ``` # user_timeout is an optional argument. nil means no timeout. def method(..., user_timeout=nil) abs_timeout = user_timeout ? now + user_timeout : nil loop { IO.select(rs, ws, es, user_timeout ? (abs_timeout - now).clamp(0..) : nil) raise "timeout" if abs_timeout && (abs_timeout < now) ... } end ``` It is possible to reduce a conditional if we use Float::INFINITY. (`abs_timeout && (abs_timeout < now)` is changed to `abs_timeout < now`) ``` # user_timeout is an optional argument. nil means no timeout. def method(..., user_timeout=nil) abs_timeout = user_timeout ? now + user_timeout : Float::INFINITY loop { IO.select(rs, ws, es, abs_timeout != Float::INFINITY ? (abs_timeout - now).clamp(0..) : nil) raise "timeout" if abs_timeout < now ... } end ``` If IO.select accepts Float::INFINITY as a timeout argument (this proposal), we can reduce one more conditional as follows. ``` # user_timeout is an optional argument. nil means no timeout. def method(..., user_timeout=nil) abs_timeout = user_timeout ? now + user_timeout : Float::INFINITY loop { IO.select(rs, ws, es, (abs_timeout - now).clamp(0..)) raise "timeout" if abs_timeout < now ... } end ``` Example 2: minimum of timeouts Sometimes we need to choose the minimum of several timeouts. I think many event-driven programs use this strategy to determine the timeout for select function. If "no timeout" is represented as nil, `[t1, t2, t3, ...].compact.min` is the minimum. If "no timeout" is represented as Float::INFINITY, we can remove `compact`: `[t1, t2, t3, ...].min` However, Float::INFINITY must be converted to nil for IO.select. This proposal removes this conversion. Example 3: maximum of timeouts Sometimes we need to choose the maximum of several timeouts. We encountered this situation with a Happy Eyeballs implementation. There are two timeouts for getaddrinfo and connect. We need to wait the longer timeout because a timeout for one doesn't stop another. Also, we don't ignore results after a timeout as long as the algorithm waits for something. If "no timeout" is represented as nil, `ts = [t1, t2, t3, ...]; ts.include?(nil) ? nil : ts.max` is the maximum. If "no timeout" is represented as Float::INFINITY, we can compute the maximum more easily: `[t1, t2, t3, ...].max` It makes code simpler. However, Float::INFINITY must be converted to nil for IO.select. This proposal removes this conversion. Several Consideration: Consideration 1: Methods other than IO.select. Several methods take a timeout. An incomplete list of methods is as follows. (I searched rb_time_interval.) - IO.select(rs, ws, es, timeout) - sleep(secs) - TCPSocket.new(connect_timeout:) - io.wait_readable(timeout) - io.wait_writable(timeout) - io.wait_priority(timeout) - mutex.sleep(timeout) Do we want to modify them consistently to accept Float::INFINITY? Consideration 2: C-level API If we want to change the timeout of many methods, we would wish to new C-level API similar to rb_time_interval but can return NULL. Unfortunately, rb_time_interval cannot return NULL because the return type is struct timeval. Note that ext/io/wait/wait.c contains get_timeout function. It seems a good first step for such API. Consideration 3: IEEE 754 dependency. Minor platforms (such as VAX) use non-IEEE 754 floating point numbers without infinity. Note that NetBSD/vax still works. (And there is an emulator, simh). Consideration 4: It seems no major languages accept infinity as select's timeout. I found Perl, Python, and OCaml take a floating point number as a timeout of select function. But they don't accept infinity. -- https://bugs.ruby-lang.org/

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[ruby-core:116085] [Ruby master Bug#20165] Ractors moving a Struct breaks beyond the first 3 fields
by codekitchen (Brian Palmer) 09 May '25

09 May '25

Issue #20165 has been reported by codekitchen (Brian Palmer). ---------------------------------------- Bug #20165: Ractors moving a Struct breaks beyond the first 3 fields https://bugs.ruby-lang.org/issues/20165 * Author: codekitchen (Brian Palmer) * Status: Open * Priority: Normal * ruby -v: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Experimenting with Ractors on ruby 3.3.0, and I'm seeing a bug where if you move a struct between ractors, all but the first 3 fields are set to nil. ``` ruby Foo = Struct.new(:a,:b,:c,:d,:e,:f) r = Ractor.new { foo = Foo[0,0,0,0,0,0] p foo Ractor.yield(foo, move: true) } p r.take ``` ``` ❯ ruby -v ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23] ❯ ruby rbug.rb rbug.rb:3: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. #<struct Foo a=0, b=0, c=0, d=0, e=0, f=0> #<struct Foo a=0, b=0, c=0, d=nil, e=nil, f=nil> ``` This seems specific to moving, if I set `move: false` the struct makes it across OK. -- https://bugs.ruby-lang.org/

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[ruby-core:119941] [Ruby master Bug#20897] resolv: not usable across ractors
by chucke (Tiago Cardoso) 09 May '25

09 May '25

Issue #20897 has been reported by chucke (Tiago Cardoso). ---------------------------------------- Bug #20897: resolv: not usable across ractors https://bugs.ruby-lang.org/issues/20897 * Author: chucke (Tiago Cardoso) * Status: Open * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Using the `resolv` library in a non-main ractor is impossible, due to DNS resources being memoized in a mutable class variable. [This patch](https://github.com/ruby/resolv/pull/62) fixes it by storing resource information in static variables. -- https://bugs.ruby-lang.org/

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[ruby-core:120840] [Ruby master Misc#21100] DevMeeting before or after RubyKaigi2025
by ko1 (Koichi Sasada) 09 May '25

09 May '25

Issue #21100 has been reported by ko1 (Koichi Sasada). ---------------------------------------- Misc #21100: DevMeeting before or after RubyKaigi2025 https://bugs.ruby-lang.org/issues/21100 * Author: ko1 (Koichi Sasada) * Status: Open ---------------------------------------- RubyKaigi 2025 will be at Matsuyama, Japan, Apr 16th - 18th. We would like to try to hold a face-to-face dev meeting at Matsuyama. (@matz will also participate!) * Date: 2025/04/15 (Tue.) 16:00-19:00 (The day before RubyKaigi) * Location: Ehime-ken Sogo Shakai Fukushi Kaikan, 3F Training room (in Japanese) 愛媛県総合社会福祉会館3F 研修室 ### How to participate Open to any RubyKaigi attendees who have a commit bit or who have a topic they particularly want to discuss. Please sign up on the doorkeeper page: https://rubyassociation.doorkeeper.jp/events/181721 The meeting will be held in a hackathon event. Please enjoy Ruby hacking with friends if you want before the meeting. Note: Do not forget to register RubyKaigi ticket too (see "[ruby-core:120816] Invitation to RubyKaigi 2025" from Akira). ### Program * 10:00am door open and start the Hackathon event * 3:00pm(?) Matz will arrive * 4:00pm opening and self introduction * 4:30pm discuss topics * 6:00pm closing and free time (closing time is depends on topics) * 7:00pm door close ### Call for agenda items If you have a ticket that you want matz and committers to discuss, please post it into this ticket in the following format: ``` * [Ticket ref] Ticket title (your name) * Comment (A summary of the ticket, why you put this ticket here, what point should be discussed, etc.) ``` Example: ``` * [Feature #14609] `Kernel#p` without args shows the receiver (ko1) * I feel this feature is very useful and some people say :+1: so let discuss this feature. ``` - It is recommended to add a comment by 2025/04/10. I'll ask Matz which should be discussed on this meeting and reorder them. - The format is strict. We'll use [this script to automatically create an markdown-style agenda](https://gist.github.com/mame/b0390509ce1491b43610b9ebb665eb86). We may ignore a comment that does not follow the format. - Your comment is mandatory. We cannot read all discussion of the ticket in a limited time. We appreciate it if you could write a short summary and update from a previous discussion. -- https://bugs.ruby-lang.org/

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[ruby-core:112091] [Ruby master Bug#19387] Issue with ObjectSpace.each_objects not returning IO objects after starting a ractor
by luke-gru (Luke Gruber) 09 May '25

09 May '25

Issue #19387 has been reported by luke-gru (Luke Gruber). ---------------------------------------- Bug #19387: Issue with ObjectSpace.each_objects not returning IO objects after starting a ractor https://bugs.ruby-lang.org/issues/19387 * Author: luke-gru (Luke Gruber) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- ```ruby r = Ractor.new do receive # block, the problem is not the termination of the ractor but the starting end ObjectSpace.each_object(IO) { |io| p io # we get no objects } ``` -- https://bugs.ruby-lang.org/

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[ruby-core:112207] [Ruby master Bug#19408] Object no longer frozen after moved from a ractor
by luke-gru (Luke Gruber) 09 May '25

09 May '25

Issue #19408 has been reported by luke-gru (Luke Gruber). ---------------------------------------- Bug #19408: Object no longer frozen after moved from a ractor https://bugs.ruby-lang.org/issues/19408 * Author: luke-gru (Luke Gruber) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- I think frozen objects should still be frozen after a move. ```ruby r = Ractor.new do obj = receive p obj.frozen? # should be true but is false p obj end obj = [Object.new].freeze r.send(obj, move: true) r.take ``` -- https://bugs.ruby-lang.org/

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