July 2023 - ruby-core - ml.ruby-lang.org

[ruby-core:113180] [Ruby master Feature#19588] Allow Comparable#clamp(min, max) to accept nil as a specification

by kyanagi (Kouhei Yanagita)

Issue #19588 has been reported by kyanagi (Kouhei Yanagita). ---------------------------------------- Feature #19588: Allow Comparable#clamp(min, max) to accept nil as a specification https://bugs.ruby-lang.org/issues/19588 * Author: kyanagi (Kouhei Yanagita) * Status: Open * Priority: Normal ---------------------------------------- `Comparable#clamp(min, max)` (with two arguments) accepts `nil`. This behaves the same as beginless/endless Range. ~~~ruby 5.clamp(nil, 0) # => 0 5.clamp(10, nil) # => 10 5.clamp(..0) # => 0 5.clamp(10..) # => 10 ~~~ This behavior is not documented. Presumably, this was not introduced intentionally. The old Rubies did not accept accept a `Range` argument. In Ruby 2.7, accepting `Range` as an argument was introduced. At that time, the approach of passing `nil` as a two-argument method was also discussed but not adopted, and using Range was chosen instead. https://bugs.ruby-lang.org/issues/14784 However, in Ruby 3.0, the behavior of `clamp` has changed to accept `nil`. This change is not documented in the NEWS or the documentation for `clamp`, and I believe that it was not an intentional change. ~~~ % docker run -it --rm rubylang/all-ruby env ALL_RUBY_SINCE=ruby-2.4.0 ./all-ruby -e "p 5.clamp(0, nil)" ruby-2.4.0 -e:1:in `clamp': comparison of Integer with nil failed (ArgumentError) from -e:1:in `<main>' exit 1 ... ruby-2.7.8 -e:1:in `clamp': comparison of Integer with nil failed (ArgumentError) from -e:1:in `<main>' exit 1 ruby-3.0.0-preview1 5 ... ruby-3.2.2 5 ~~~ It seems that https://github.com/ruby/ruby/commit/a93da4970be44a473b7b42e7516eb2663dece2c3 brought about this change. How about making the current behavior a specification? It has been three years since the behavior changed, and I don't see much point in prohibiting `nil` now. -- https://bugs.ruby-lang.org/

5 months, 1 week

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[ruby-core:114025] [Ruby master Feature#19744] Namespace on read

by tagomoris (Satoshi TAGOMORI)

Issue #19744 has been reported by tagomoris (Satoshi TAGOMORI). ---------------------------------------- Feature #19744: Namespace on read https://bugs.ruby-lang.org/issues/19744 * Author: tagomoris (Satoshi TAGOMORI) * Status: Open * Priority: Normal ---------------------------------------- # What is the "Namespace on read" This proposes a new feature to define virtual top-level namespaces in Ruby. Those namespaces can require/load libraries (either .rb or native extension) separately from the global namespace. Dependencies of required/loaded libraries are also required/loaded in the namespace. ### Motivation The "namespace on read" can solve the 2 problems below, and can make a path to solve another problem: The details of those motivations are described in the below section ("Motivation details"). #### Avoiding name conflicts between libraries Applications can require two different libraries safely which use the same module name. #### Avoiding unexpected globally shared modules/objects Applications can make an independent/unshared module instance. #### (In the future) Multiple versions of gems can be required Application developers will have fewer version conflicts between gem dependencies if rubygems/bundler will support the namespace on read. ### Example code with this feature ```ruby # your_module module YourModule end # my_module.rb require 'your_module' module MyModule end # example.rb namespace1 = NameSpace.new namespace1.require('my_module') #=> true namespace1::MyModule #=> #<Module:0x00000001027ea650>::MyModule (or #<NameSpace:0x00...>::MyModule ?) namespace1::YourModule # similar to the above MyModule # NameError YourModule # NameError namespace2 = NameSpace.new # Any number of namespaces can be defined namespace2.require('my_module') # Different library "instance" from namespace1 require 'my_module' # require in the global namespace MyModule.object_id != namespace1::MyModule.object_id #=> true namespace1::MyModule.object_id != namespace2::MyModule.object_id ``` The required/loaded libraries will define different "instances" of modules/classes in those namespaces (just like the "wrapper" 2nd argument of `Kernel.load`). This doesn't introduce compatibility problems if all libraries use relative name resolution (without forced top-level reference like `::Name`). # "On read": optional, user-driven feature "On read" is a key thing of this feature. That means: * No changes are required in existing/new libraries (except for limited cases, described below) * No changes are required in applications if it doesn't need namespaces * Users can enable/use namespaces just for limited code in the whole library/application Users can start using this feature step by step (if they want it) without any big jumps. ## Motivation details This feature can solve multiple problems I have in writing/executing Ruby code. Those are from the 3 problems I mentioned above: name conflicts, globally shared modules, and library version conflicts between dependencies. I'll describe 4 scenarios about those problems. ### Running multiple applications on a Ruby process Modern computers have many CPU cores and large memory spaces. We sometimes want to have many separate applications (either micro-service architecture or modular monolith). Currently, running those applications require different processes. It requires additional computation costs (especially in developing those applications). If we have isolated namespaces and can load applications in those namespaces, we'll be able to run apps on a process, with less overhead. (I want to run many AWS Lambda applications on a process in isolated namespaces.) ### Running tests in isolated namespaces Tests that require external libraries need many hacks to: * require a library multiple times * require many different 3rd party libraries into isolated spaces (those may conflict with each other) Software with plugin systems (for example, Fluentd) will get benefit from namespaces. In addition to it, application tests can avoid unexpected side effects if tests are executed in isolated namespaces. ### Safely isolated library instances Libraries may have globally shared states. For example, [Oj](https://github.com/ohler55/oj) has a global `Obj.default_options` object to change the library behavior. Those options may be changed by any dependency libraries or applications, and it changes the behavior of `Oj` globally, unexpectedly. For such libraries, we'll be able to instantiate a safe library instance in an isolated namespace. ### Avoiding dependency hells Modern applications use many libraries, and those libraries require much more dependencies. Those dependencies will cause version conflicts very often. In such cases, application developers should resolve those by updating each libraries, or should just wait for the new release of libraries to conflict those libraries. Sometimes, library maintainers don't release updated versions, and application developers can do nothing. If namespaces can require/load a library multiple times, it also enables to require/load different versions of a library in a process. It requires the support of rubygems, but namespaces should be a good fundamental of it. ## Expected problems ### Use of top-level references In my expectation, `::Name` should refer the top-level `Name` in the global namespace. I expect that `::ENV` should contain the environment variables. But it may cause compatibility problems if library code uses `::MyLibrary` to refer themselves in their deeply nested library code. ### Additional memory consumption An extension library (dynamically linked library) may be loaded multiple times (by `dlopen` for temporarily copied dll files) to load isolated library "instances" if different namespaces require the same extension library. That consumes additional memory. In my opinion, additional memory consumption is a minimum cost to realize loading extension libraries multiple times without compatibility issues. This occurs only when programmers use namespaces. And it's only about libraries that are used in 2 or more namespaces. ### The change of `dlopen` flag about extension libraries To load an extension library multiple times without conflicting symbols, all extensions should stop sharing symbols globally. Libraries referring symbols from other extension libraries will have to change code & dependencies. (About the things about extension libraries, [Naruse also wrote an entry](https://naruse.hateblo.jp/entry/2023/05/22/193411).) # Misc The proof-of-concept branch is here: https://github.com/tagomoris/ruby/pull/1 It's still work-in-progress branch, especially for extension libraries. -- https://bugs.ruby-lang.org/

5 months, 3 weeks

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[ruby-core:111074] [Ruby master Bug#19160] cmp_clamp arguments

by kaiquekandykoga

Issue #19160 has been reported by kaiquekandykoga (Kaíque Koga). ---------------------------------------- Bug #19160: cmp_clamp arguments https://bugs.ruby-lang.org/issues/19160 * Author: kaiquekandykoga (Kaíque Koga) * Status: Open * Priority: Normal * ruby -v: ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-freebsd13.1] * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN ---------------------------------------- If clamp receives min higher than max, it will raise an exception. The message says *min argument must be smaller than max argument* , but min can actually be equal to max too. Patch https://github.com/ruby/ruby/pull/6802. -- https://bugs.ruby-lang.org/

5 months, 3 weeks

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[ruby-core:113107] [Ruby master Bug#19576] Backport request: Gemfile.lock resolving is broken with bundler shipped with Ruby 3.1.4

by jprokop (Jarek Prokop)

Issue #19576 has been reported by jprokop (Jarek Prokop). ---------------------------------------- Bug #19576: Backport request: Gemfile.lock resolving is broken with bundler shipped with Ruby 3.1.4 https://bugs.ruby-lang.org/issues/19576 * Author: jprokop (Jarek Prokop) * Status: Open * Priority: Normal * ruby -v: ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux] * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- This is a backport request for bundler, that regressed in 2.3.36 in a specific situation. Newer and older bundler versions that ship with Ruby are not problematic, only the version that ships with Ruby version >= 3.1.3. A few weeks ago, we discovered a bug in resolving in bundler shipped with Ruby 3.1.3 and 3.1.4: Bundler version: ``` $ bundler --version Bundler version 2.3.26 ``` Affected rubies `ruby -v`: First: ``` $ ruby -v ruby 3.1.4p223 (2023-03-30 revision 957bb7cb81) [x86_64-linux] ``` Second: ``` $ruby -v ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux] ``` Initial bug report with reproducer and more in-depth description can be found here: https://github.com/sclorg/s2i-ruby-container/issues/469 Using the following Gemfile for a rails app: https://github.com/sclorg/rails-ex/blob/67b7a61eae9efa1088ff3f634ae316e1022… bundler locks up in trying to resolve Nokogiri for Ruby 3.1, but keeps failing because it keeps using incompatible built binary gem instead of falling back to installing and building the binary extension of Nokogiri locally. We craft this Gemfile to be usable from Ruby 2.5 up to Ruby 3.1, as the app is used mainly for testing. I have created a patch to fix the situation, see the attached files. There are 2 of them, one contains the fix and the other one contains the test from the rubygems repo PR#6225. full commit available here: https://src.fedoraproject.org/fork/jackorp/rpms/ruby/c/5ef600a8f40b76de5636… The patches are created from the following upstream changes in bundler: https://github.com/rubygems/rubygems/pull/6225 and adapted: https://github.com/rubygems/rubygems/commit/7b64c64262a7a980c0eb23b96ea56cf… for the PR#6225. With the fix applied I no longer have issues doing `bundle install` with our Gemfile.lock. ---Files-------------------------------- rubygem-bundler-2.3.26-Tests-from-bundler-PR-6225.patch (1.82 KB) rubygem-bundler-2.3.26-Provide-fix-for-bundler-Gemfile-resolving-regression.patch (5.21 KB) -- https://bugs.ruby-lang.org/

6 months

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[ruby-core:114072] [Ruby master Bug#19754] `IO::Buffer#get_string` raises unsuitable exception for too large offset

by nobu (Nobuyoshi Nakada)

Issue #19754 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #19754: `IO::Buffer#get_string` raises unsuitable exception for too large offset https://bugs.ruby-lang.org/issues/19754 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Priority: Normal * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- The message seems suitable when both of `offset` and `length` are given. ```ruby IO::Buffer.for("test").get_string(5, 0) #=> Specified offset+length exceeds buffer size! (ArgumentError) ``` But without `length`, it doesn't seem to check `offset` properly. ```ruby IO::Buffer.for("test").get_string(5) #=> negative string size (or size too big) (ArgumentError) ``` -- https://bugs.ruby-lang.org/

6 months

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[ruby-core:111953] [Ruby master Bug#19362] #dup on Proc doesn't call initialize_dup

by zverok (Victor Shepelev)

Issue #19362 has been reported by zverok (Victor Shepelev). ---------------------------------------- Bug #19362: #dup on Proc doesn't call initialize_dup https://bugs.ruby-lang.org/issues/19362 * Author: zverok (Victor Shepelev) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- In #17545, `#dup` had changed to create an instance of the subclass. It, though, doesn't invoke `initialize_dup` of the subclass, unlike other standard classes. ```ruby class MyAry < Array def initialize_dup(...) p(self.class, ...) super end end class MyString < String def initialize_dup(...) p(self.class, ...) super end end class MyProc < Proc def initialize_dup(...) p(self.class, ...) super end end MyString.new('test').dup # prints MyString, "test" MyAry.new(['test']).dup # prints MyAry, ["test"] MyProc.new { 'test' }.dup # doesn't print anything ``` This makes the change in #17545 useless: while inheriting from core classes is indeed marginal, one of author's intention might be carrying additional information with the Proc instance, and bypassing `#initialize_dup` makes it impossible to maintain this information. It seems that actually `#initialize_dup` is also invoked on the core classes themselves, but ignored on `Proc`. ```ruby class Array def initialize_dup(...) p(self.class, ...) super end end class String def initialize_dup(...) p(self.class, ...) super end end class Proc def initialize_dup(...) p(self.class, ...) super end end 'test'.dup # prints String, "test" ['test'].dup # prints Array, ["test"] Proc.new { 'test' }.dup # doesn't print anything ``` Which is an even more marginal problem but still an inconsistency. -- https://bugs.ruby-lang.org/

6 months, 2 weeks

3
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[ruby-core:114070] [Ruby master Bug#19753] IO::Buffer#get_string can't handle negative offset

by noteflakes (Sharon Rosner)

Issue #19753 has been reported by noteflakes (Sharon Rosner). ---------------------------------------- Bug #19753: IO::Buffer#get_string can't handle negative offset https://bugs.ruby-lang.org/issues/19753 * Author: noteflakes (Sharon Rosner) * Status: Open * Priority: Normal * ruby -v: 3.2 * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- ```ruby irb(main):001:0> b = IO::Buffer.for('abc') => #<IO::Buffer 0x00007f858f5450c0+3 EXTERNAL READONLY SLICE> ... irb(main):002:0> b.get_string(-1) => "\x00abc" irb(main):003:0> b.get_string(-1000, 3) (irb):3:in `get_string': Specified offset+length exceeds data size! (ArgumentError) from (irb):3:in `<main>' from /home/sharon/.rbenv/versions/3.2.0/lib/ruby/gems/3.2.0/gems/irb-1.7.1/exe/irb:9:in `<top (required)>' from /home/sharon/.rbenv/versions/3.2.0/bin/irb:25:in `load' from /home/sharon/.rbenv/versions/3.2.0/bin/irb:25:in `<main>' ``` Using a negative offset returns garbage in the string but it also might segfault: ```ruby irb(main):003:0> b = IO::Buffer.map(File.open('sgt-nodes.sql', 'r+')) => #<IO::Buffer 0x00007f189de14000+2008858 EXTERNAL MAPPED SHARED> irb(main):004:0> b.get_string(-1000) (irb):4: [BUG] Segmentation fault at 0x00007f189de13c18 ruby 3.2.0 (2022-12-25 revision a528908271) [x86_64-linux] -- Control frame information ----------------------------------------------- c:0021 p:---- s:0109 e:000108 CFUNC :get_string ... ``` ## Expected behaviour I think it might be nice to have `#get_string` behave like other methods taking an offset, like `String#[]`. For example: ```ruby irb(main):001:0> b = IO::Buffer.for('abc') => #<IO::Buffer 0x00007f858f5450c0+3 EXTERNAL READONLY SLICE> ... irb(main):002:0> b.get_string(-1) => "c" irb(main):003:0> b.get_string(-2) => "bc" irb(main):003:0> b.get_string(-1000) => "abc" irb(main):003:0> b.get_string(-1000, 2) => "ab" ``` -- https://bugs.ruby-lang.org/

6 months, 2 weeks

4
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[ruby-core:112944] [Ruby master Feature#19541] Proposal: Generate frame unwinding info for YJIT code

by kjtsanaktsidis (KJ Tsanaktsidis)

Issue #19541 has been reported by kjtsanaktsidis (KJ Tsanaktsidis). ---------------------------------------- Feature #19541: Proposal: Generate frame unwinding info for YJIT code https://bugs.ruby-lang.org/issues/19541 * Author: kjtsanaktsidis (KJ Tsanaktsidis) * Status: Open * Priority: Normal ---------------------------------------- ## What is being propsed? Currently, Ruby crashes with yjit generated code on the stack, `rb_print_backtrace()` is unable to actually show any frames underneath the yjit code. For example, if you send SIGSEGV to a Ruby process running yjit, this is what you see: ``` /ruby/miniruby(rb_print_backtrace+0xc) [0xaaaad0276884] /ruby/vm_dump.c:785 /ruby/miniruby(rb_vm_bugreport) /ruby/vm_dump.c:1093 /ruby/miniruby(rb_bug_for_fatal_signal+0xd0) [0xaaaad0075580] /ruby/error.c:813 /ruby/miniruby(sigsegv+0x5c) [0xaaaad01bedac] /ruby/signal.c:919 linux-vdso.so.1(__kernel_rt_sigreturn+0x0) [0xffff91a3e8bc] /ruby/miniruby(map<(usize, yjit::backend::ir::Insn), (usize, yjit::backend::ir::Insn), yjit::backend::ir::{impl#17}::next_mapped::{closure_env#0}>+0x8c) [0xaaaad03b8b00] /rustc/897e37553bba8b42751c67658967889d11ecd120/library/core/src/option.rs:929 /ruby/miniruby(next_mapped+0x3c) [0xaaaad0291dc0] src/backend/ir.rs:1225 /ruby/miniruby(arm64_split+0x114) [0xaaaad0287744] src/backend/arm64/mod.rs:359 /ruby/miniruby(compile_with_regs+0x80) [0xaaaad028bf84] src/backend/arm64/mod.rs:1106 /ruby/miniruby(compile+0xc4) [0xaaaad0291ae0] src/backend/ir.rs:1158 /ruby/miniruby(gen_single_block+0xe44) [0xaaaad02b1f88] src/codegen.rs:854 /ruby/miniruby(gen_block_series_body+0x9c) [0xaaaad03b0250] src/core.rs:1698 /ruby/miniruby(gen_block_series+0x50) [0xaaaad03b0100] src/core.rs:1676 /ruby/miniruby(branch_stub_hit_body+0x80c) [0xaaaad03b1f68] src/core.rs:2021 /ruby/miniruby({closure#0}+0x28) [0xaaaad02eb86c] src/core.rs:1924 /ruby/miniruby(do_call<yjit::core::branch_stub_hit::{closure_env#0}, *const u8>+0x98) [0xaaaad035ba3c] /rustc/897e37553bba8b42751c67658967889d11ecd120/library/std/src/panicking.rs:492 [0xaaaad035c9b4] ``` (n.b. - I compiled Ruby with `-fasynchronous-unwind-tables –rdynamic –g` in cflags to make sure gcc generates appropriate unwind info & keeps the symbol tables). Likewise, if you attach gdb to a Ruby process with yjit enabled, gdb can't show thread backtraces through yjit-generated code either. My proposal is that YJIT generate sufficient unwinding and debug information on all platforms to allow both `rb_print_backtrace()` and the platform's debugger (gdb/lldb/WinDbg) to show: * Full stack traces all the way back to `main`. That is, it should be possible to see frames _underneath_ `[0xaaaad035c9b4]` from the backtrace above. * Names for the dynamically generated yjit blocks (e.g. instead of `[0xaaaad035c9b4]`, we should see something like `yjit$$name_of_ruby_method`, where `name_of_ruby_method` is the `label` for the iseq this is JIT'd code for). ## Motivation I have a few motivations for wanting this. Firstly, I feel this functionality is independently useful. When Ruby crashes, the more information we can get, the more likely we are to find the root cause. Likewise, the same principle applies to debugging with gdb - you can get a fuller understanding of what the process is doing if you see the whole stack. I have often found attaching gdb to the Ruby interpreter helps in understanding problems in Ruby code or C extensions and is something I do relatively frequently; yjit breaking that will definitely be inconvenient for me! ## Implementation I have a draft implementation here on how I'd implement this: . It's currently missing tests & platform support (it only works on Linux aarch64). Also, it implements unwind info generation, so unwinding can work _through_ yjit code, but it does not currently emit symbols to give _names_ to those yjit frames. My PR contains a document which explains how the Linux interfaces for registering unwind info for JIT'd code work, so I won't duplicate that information here. The biggest implementation question I had is around the use of Rust crates. Currently, I prototyped my implementation using the gimli & object crates, for generating DWARF info and ELF binaries. However, the yjit build does purposefully does not use cargo & external crates for release builds. There are a few different ways we could go here: * Don't use the gimli & object crates; instead, re-implement all debug info & object file generation code in yjit. * Don't use the crates; instead, link againt C libraries to provide this functionality & call them from Rust (perhaps some combination of libelf, libdw, libbfd, or llvm might do what we need) * Use cargo after all for the release build & download the crates at build-time * Use cargo for the release build, but vendor everything, so the build doesn't need to download anything * Only make unwind info generation available in dev mode where cargo is used, and so mark the gimli/object dependencies as optional in Cargo.toml. We'd need to decide on one of these approaches for this proposal to work. I don't really have a strong sense of the pros/cons of each. (Side note - my PR actually depends on a _fork_ of gimli - I've been discussing adding the needed interfaces upstream here: https://github.com/gimli-rs/gimli/issues/648). ## Benchmarks I ran the yit-bench suite on my branch and compared it to Ruby master: * My branch: https://gist.github.com/KJTsanaktsidis/5741a9f64e5cd75cdf5fedd846091a4f * Ruby master: https://gist.github.com/KJTsanaktsidis/592d3ebcf98f6745dfa3efbd30a25acf This is a (very simple) comparison: ``` -------------- ------------ ------------ --------------- bench yjit (ms) branch (ms) branch/yjit (%) activerecord 97.5 98.5 101.03% hexapdf 2415.3 2458.2 101.78% liquid-c 61.9 63.1 101.94% liquid-render 135.3 135.0 99.78% mail 104.6 105.5 100.86% psych-load 1887.1 1922.0 101.85% railsbench 1544.4 1556.0 100.75% ruby-lsp 88.4 89.5 101.24% sequel 147.5 151.1 102.44% binarytrees 303 305.6 100.86% chunky_png 1075.8 1079.4 100.33% erubi 392.9 392.3 99.85% erubi_rails 14.7 14.7 100.00% etanni 792.3 791.4 99.89% fannkuchredux 3815.9 3813.6 99.94% lee 1030.2 1039.2 100.87% nbody 49.2 49.3 100.20% optcarrot 4142 4143.3 100.03% ruby-json 2860.7 2874.0 100.46% rubykon 7906.6 7904.2 99.97% 30k_ifelse 348.7 345.4 99.05% 30k_methods 828.6 831.8 100.39% cfunc_itself 28.8 28.9 100.35% fib 34.4 34.5 100.29% getivar 115.5 109.7 94.98% keyword_args 37.7 38.0 100.80% respond_to 26 26.1 100.38% setivar 33.8 33.5 99.11% setivar_object 208.7 194.3 93.10% str_concat 52.6 52.2 99.24% throw 23.8 24.1 101.26% -------------- ------------ ------------ --------------- ``` It seems like the performance impact of generating and registering the debug info is marginal. -- https://bugs.ruby-lang.org/

6 months, 3 weeks

7
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[ruby-core:112326] [Ruby master Feature#19430] Contribution wanted: DNS lookup by c-ares library

by mame (Yusuke Endoh)

Issue #19430 has been reported by mame (Yusuke Endoh). ---------------------------------------- Feature #19430: Contribution wanted: DNS lookup by c-ares library https://bugs.ruby-lang.org/issues/19430 * Author: mame (Yusuke Endoh) * Status: Open * Priority: Normal ---------------------------------------- ## Problem At the present time, Ruby uses `getaddrinfo(3)` to resolve names. Because this function is synchronous, we cannot interrupt the thread performing name resolution until the DNS server returns a response. We can see this behavior by setting blackhole.webpagetest.org (72.66.115.13) as a DNS server, which swallows all packets, and resolving any name: ``` # cat /etc/resolv.conf nameserver 72.66.115.13 # ./local/bin/ruby -rsocket -e 'Addrinfo.getaddrinfo("www.ruby-lang.org", 80)' ^C^C^C^C ``` As we see, Ctrl+C does not stop ruby. The current workaround that users can take is to do name resolution in a Ruby thread. ```ruby Thread.new { Addrinfo.getaddrinfo("www.ruby-lang.org", 80) }.value ``` The thread that calls this code is interruptible. (Note that the newly created thread itself will be stuck until the DNS lookup exceeds the time out.) ## Proposal We can solve this problem by using c-ares, which is an asynchronous name resolver, as a backend of `Addrinfo.getaddrinfo`, etc. (@sorah told me about this library, thanks!) https://c-ares.org/ I have created a PoC patch. https://github.com/mame/ruby/commit/547806146993bbc25984011d423dcc0f913b211c By applying this patch, we can interrupt `Addrinfo.getaddrinfo` by Ctrl+C. ``` # cat /etc/resolv.conf nameserver 72.66.115.13 # ./local/bin/ruby -rsocket -e 'Addrinfo.getaddrinfo("www.ruby-lang.org", 80)' ^C-e:1:in `getaddrinfo': Interrupt from -e:1:in `<main>' ``` ## Discussion ### About c-ares According to the site of c-ares, some major tools including libcurl, Wireshark, and Apache Arrow are already using c-ares. In the language interpreter, node.js seems to be using c-ares. I am honestly not sure about the compatibility of c-ares with `getaddrinfo(3)`. I guess there is no major incompatibility because I have not experienced any name resolution problem of curl. @akr (who is the author and maintainer of Ruby's socket library) suggested to check if OS-specific name resolution, e.g., WINS on Windows, NIS on Solaris, etc., is supported. He also said that it may be acceptable even if they are not supported. Whether to bundle c-ares source code with ruby would require further discussion. If this proposal is accepted, then c-ares will become a de facto essential dependency for practical use, like gmp, in my opinion. Incidentally, node.js bundles c-ares: https://github.com/nodejs/node/tree/main/deps/cares ### Alternative approaches Recent glibc provides `getaddrinfo_a(3)` which performs asynchronous name resolution. However, this function has a fatal problem of being incompatible with `fork(2)`, which is heavily used in the Ruby ecosystem. In fact, the attempt to use `getaddrinfo_a(3)` (#17134) has been revert because it fails rails tests. (#17220) Another alternative is to have a worker pthread inside Ruby that calls getaddrinfo(3). Instead of calling getaddrinfo(3) directly, `Addrinfo.getaddrinfo` would ask the worker to resolve a name and wait for a response. This method should be able to implement cancellation. (Simply put, this means reimplementation of getaddrinfo_a(3) on our own, taking into account of `fork(2).) This has the advantages: not adding dependencies on external libraries and not having compatibility issues with `getaddrinfo(3)`. However, it is considerably more difficult to implement and maintain. An internal pthread may have a non-trivial impact on the execution efficiency and memory usage. Also, we may need to implement a mechanism to dynamically change the number of workers depending on the load. It would be ideal if we could try and evaluate both approaches. But my current impression is that using c-ares is the quickest and best compromise. ## Contribution wanted I have made it up to the PoC, but don't have much time to complete this. @naruse suggested me to create a ticket asking for contributions. Is anyone interested in this? * This patch changes `rsock_getaddrinfo` to accept a timeout argument. There are several places where Qnil is passed as a timeout (where I add `// TODO` in the PoC). We need to consider what timeout we should pass. * This cares only `getaddrinfo`, but we also need to care `getnameinfo` (and something else if any). There may be some issues I'm not aware of. * I have not yet tested this PoC seriously. It would be great if we could evaluate it with some real apps. Also, it would be great to hear from someone who knows more about c-ares. -- https://bugs.ruby-lang.org/

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[ruby-core:114250] [Ruby master Bug#19778] mkmf.rb pkg_config() interaction with RbConfig::CONFIG["cflags"]

by rhenium (Kazuki Yamaguchi)

Issue #19778 has been reported by rhenium (Kazuki Yamaguchi). ---------------------------------------- Bug #19778: mkmf.rb pkg_config() interaction with RbConfig::CONFIG["cflags"] https://bugs.ruby-lang.org/issues/19778 * Author: rhenium (Kazuki Yamaguchi) * Status: Open * Priority: Normal * ruby -v: ruby 3.3.0dev (2023-07-21T09:38:29Z master 22f9735587) [x86_64-linux] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- (This was first reported at https://github.com/ruby/openssl/issues/650: The extension's build breaks in a strange way if `RbConfig::CONFIG["*flags"]` contains the path of an OpenSSL installation but `pkg-config` returns the path of a different OpenSSL installation) Commit commit:097c3e9cbbf23718371f08c24b2d2297b039f63f ("mkmf.rb: -I flags to $INCFLAGS", Ruby 2.2) changed how mkmf's `pkg_config()` handles the result of the `pkg-config` command. It now stores the `-I` flags in $INCFLAGS and others in $CFLAGS. mkmf generates a Makefile that compiles source files with: $(CC) $(INCFLAGS) $(CPPFLAGS) $(CFLAGS) and link the final library with: $(LDSHARED) -o $@ $(OBJS) $(LIBPATH) $(DLDFLAGS) $(LOCAL_LIBS) $(LIBS) This "new" behavior of `pkg_config()` is problematic when `RbConfig::CONFIG["{C,CPP}FLAGS"]` also provide `-I` flags and `RbConfig::CONFIG["LDFLAGS"]` provides the matching `-L` flags -- for example, if Ruby is compiled with `./configure --with-opt-dir=<dir>`. This would end up with compiling sources with [...] -I<from pkg-config> -I<from RbConfig> [...] and then linking with [...] -L<from RbConfig> -L<from pkg-config> [...] This doesn't seem right. I don't know which should come earlier, but the order should be consistent. The commit in question clearly describes the change in the commit message, but it doesn't have a linked issue. What is it intended for? Also, what is $INCFLAGS? On the other hand, `dir_config()` would prepend `-I` flags to $CPPFLAGS and `-L` flags to $LIBPATH, so it doesn't have issues with flags from `RbConfig`, albeit in a differently way. -- https://bugs.ruby-lang.org/

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ruby-core July 2023