From: merch-redmine@... Date: 2021-07-27T21:48:15+00:00 Subject: [ruby-core:104713] [Ruby master Bug#10902] require("enumerator") scans LOAD_PATH 2x on every invocation Issue #10902 has been updated by jeremyevans0 (Jeremy Evans). If we want to allow loading an `enumerator.rb` library, then we cannot avoid the scan of the load path for *.rb files. However, we can avoid scanning the load path twice, once for `enumerator.rb` and once for `enumerator.so`, since we already know we loaded `enumerator.so`. I've submitted a pull request to do that: https://github.com/ruby/ruby/pull/4687 ---------------------------------------- Bug #10902: require("enumerator") scans LOAD_PATH 2x on every invocation https://bugs.ruby-lang.org/issues/10902#change-93040 * Author: tmm1 (Aman Gupta) * Status: Open * Priority: Normal * ruby -v: ruby 2.1.5 * Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN ---------------------------------------- On every invocation of `require "enumerator"` (for example during boot when many gems require it), the VM will scan the load path twice: once for enumerator.rb and again for enumerator.so. Of course, no file is found because enumerator is now shipped within the VM by default. ~~~ $ ruby -e' p $LOADED_FEATURES[0] ' "enumerator.so" $ ruby -e' p $LOAD_PATH.size ' 8 $ strace -e trace=open ruby -e' 1.times{ require "enumerator" } ' 2>&1 | grep enumerator.rb | wc -l 8 $ strace -e trace=open ruby -e' 1.times{ require "enumerator" } ' 2>&1 | grep enumerator.so | wc -l 8 $ strace -e trace=open ruby -e' 10.times{ require "enumerator" } ' 2>&1 | grep enumerator.so | wc -l 80 $ strace -e trace=open ruby -e' 100.times{ require "enumerator" } ' 2>&1 | grep enumerator.so | wc -l 800 ~~~ In enumerator.c, we call `rb_provide("enumerator.so")` which adds it to $LOADED_FEATURES. This means `require "enumerator.so"` can be optimized, but most libraries do not include the .so extension when requiring enumerator. -- https://bugs.ruby-lang.org/ Unsubscribe: