From: eregontp@... Date: 2017-10-26T12:41:43+00:00 Subject: [ruby-core:83578] [Ruby trunk Feature#14042] IO#puts: use writev if available Issue #14042 has been updated by Eregon (Benoit Daloze). Correction, it only breaks one spec, not mspec. The spec is "IO.popen raises IOError when writing a read-only pipe" in popen_spec.rb. I reduced the code and this behaves differently: ~~~ $ chruby trunk $ ruby -e 'IO.popen(["ruby", "-e", "sleep 1; puts :a"], "r").close' Traceback (most recent call last): 3: from -e:1:in `
' 2: from -e:1:in `puts' 1: from -e:1:in `puts' -e:1:in `write': Broken pipe @ io_writev - (Errno::EPIPE) $ chruby 2.4.2 $ ruby -e 'IO.popen(["ruby", "-e", "sleep 1; puts :a"], "r").close' ~~~ I don't understand why though. ---------------------------------------- Feature #14042: IO#puts: use writev if available https://bugs.ruby-lang.org/issues/14042#change-67606 * Author: rohitpaulk (Paul Kuruvilla) * Status: Closed * Priority: Normal * Assignee: * Target version: ---------------------------------------- Hi, I've attached a patch to make IO#puts use writev if available. Currently, IO#puts calls `write` twice: Once to write the string, and the second to write a newline (if the string doesn't end with one already). With this patch, those two calls are replaced with a single `writev` call. A test has been added that demonstrates the problem. For a bit of background: * A related issue: https://bugs.ruby-lang.org/issues/9420. (I couldn't figure out a way to 'attach' my patch to that issue, so I'm creating a new one) * A blog post I wrote a while back about this: https://hackernoon.com/rubys-puts-is-not-atomic-889c57fc9a28 Command I used to run the test I added: `make test-all TESTS='ruby/test_io.rb -n test_puts_parallel'` I'm a first time contributor, a bit confused as to where a changelog entry should be added. Is the `NEWS` file the right place? Regards, Paul ---Files-------------------------------- ruby-changes.patch (2.83 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: