From: eregontp@... Date: 2020-10-07T16:02:08+00:00 Subject: [ruby-core:100331] [Ruby master Bug#17188] Freeze Encoding objects for Ractor Issue #17188 has been updated by Eregon (Benoit Daloze). Backport set to 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ruby -v set to ruby 3.0.0preview1 (2020-09-25 master 0096d2b895) [x86_64-linux] Assignee set to ko1 (Koichi Sasada) Tracker changed from Feature to Bug Changing this to a bug, because it can cause unsafe sharing: ```ruby irb(main):003:0> Encoding::UTF_8.instance_variable_set(:@foo, Object.new) => #<Object:0x00005596506b8a28> irb(main):004:0> Ractor.new { p "b".encoding.instance_variable_get("@foo") } #<Object:0x00005596506b8a28> ``` ---------------------------------------- Bug #17188: Freeze Encoding objects for Ractor https://bugs.ruby-lang.org/issues/17188#change-87907 * Author: Eregon (Benoit Daloze) * Status: Open * Priority: Normal * Assignee: ko1 (Koichi Sasada) * Target version: 3.0 * ruby -v: ruby 3.0.0preview1 (2020-09-25 master 0096d2b895) [x86_64-linux] * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- Currently Encoding objects are not frozen: ``` $ ruby -ve 'p Encoding::US_ASCII.frozen?' ruby 3.0.0dev (2020-09-25T08:28:42Z master 81dc37b1b4) [x86_64-linux] false ``` That means they cannot be accessed in a Ractor: ```ruby irb(main):001:0> Encoding::US_ASCII => #<Encoding:US-ASCII> irb(main):002:0> Ractor.new { Encoding::US_ASCII } <internal:ractor>:38: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. => #<Ractor:#2 (irb):2 running> #<Thread:0x00005567521d81e8 run> terminated with exception (report_on_exception is true): (irb):2:in `block in irb_binding': can not access non-sharable objects in constant Encoding::US_ASCII by non-main Ractor. (NameError) ``` And `Ractor.new { p "".encoding }` is likely violating the Ractor guarantees. I think we can make all Encoding instances frozen. Making them frozen is also useful for code sharing, which TruffleRuby aims to support via the GraalVM Engine/Context API. cc @ko1 -- https://bugs.ruby-lang.org/ Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>