Issue #21451 has been updated by Eregon (Benoit Daloze). tenderlovemaking (Aaron Patterson) wrote in #note-2:
AFAIK, procs fundamentally can't be shared because their environment is mutable.
Currently `Ractor.make_shareable(proc)` makes a shallow copy of the environment, inplace. I believe that's wrong for Ruby semantics because it "breaks" an existing Proc, that's the subject of #21039. But with `copy: true` it would at least not affect existing references to the Proc, which seems significantly better, and also it makes it clearer it takes a shallow copy of the Proc environment. tenderlovemaking (Aaron Patterson) wrote in #note-2:
I think we should just accept that `rb_obj_clone` can possibly raise an exception, and we should re-raise with a more helpful exception.
I see, makes sense, agreed it's a good way. I would suggest a different message and error class to improve clarity though: ``` -e:1:in 'Ractor.make_shareable': cannot copy #<Proc:0x000000011f311a80 -e:1 (lambda)> (Ractor::IsolationError) ``` => ``` -e:1:in 'Ractor.make_shareable': cannot make #<Proc:0x000000011f311a80 -e:1 (lambda)> shareable with copy (ArgumentError) OR -e:1:in 'Ractor.make_shareable': cannot make shareable with copy: #<Proc:0x000000011f311a80 -e:1 (lambda)> (ArgumentError) ``` `Ractor::IsolationError` seems a bit strange, so I think simply `ArgumentError`, or maybe something like `Ractor::CopyError` would be better. ---------------------------------------- Bug #21451: Ractor.make_shareable(->{}, copy: true) raises unhelpful error https://bugs.ruby-lang.org/issues/21451#change-113844 * Author: tenderlovemaking (Aaron Patterson) * Status: Open * Assignee: ractor * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ```
ruby -e'Ractor.make_shareable(->{}, copy:true)' <internal:ractor>:828:in 'Ractor.make_shareable': allocator undefined for Proc (TypeError) from -e:1:in '<main>'
This error isn't very helpful and I think we can improve it. The exception happens when we call `rb_obj_clone` on the lambda.
I've made a patch to improve the error message so it's like this:
./miniruby -e'Ractor.make_shareable(->{}, copy:true)' -e:1:in 'Ractor.make_shareable': cannot copy #<Proc:0x000000011f311a80 -e:1 (lambda)> (Ractor::IsolationError) from -e:1:in '<main>' -e:1:in 'Ractor.make_shareable': allocator undefined for Proc (TypeError) from -e:1:in '<main>'
The patch is here: https://github.com/ruby/ruby/pull/13703
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