Bug #15856: Idempotent performance of Kernel.require with many activated gems is slow - Ruby master - Ruby Issue Tracking System

Bug #15856

Idempotent performance of Kernel.require with many activated gems is slow

Added by lamont (Lamont Granquist) 3 months ago. Updated 3 months ago.

Status:

Assigned

Priority:

Normal

Assignee:

hsbt (Hiroshi SHIBATA)

Target version:

ruby -v:

ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-linux]

Backport:

2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN

[ruby-core:92686]

Description

With many activated gems the performance of Kernel.require (aka Kernel.gem_original_require after rubygems is loaded) is very slow, even in the case where the require has already been loaded (the idempotent case).

What it looks like is happening is every time it needs to resolve the string argument to a pathname in order to compare against a cache of already loaded paths. Since require and require_relative need to be able to share state this makes sense to do, but this becomes very expensive with lots of activated gems, particularly on windows (where open/stat on windows is 10x more expensive than on linux).

What probably needs to happen is that for require (but not require_relative which is already fairly fast) there needs to a be another layer of idempotency checking that happens which compares only the string argument in a Hash to see if the key exists or not (which I believe is likely the old way that require used to work before require_relative was introduced). That means that on the second time a require line was processed it would find that value was true and would short circuit without doing any File I/O to resolve the filename. Of course the first time it still would need to do the check resolve to the full path and still maintain that cache so that require and require_relative were still idempotent between them.

After doing some testing I don't think this would introduce any user-visible behavior changes, since requires lines should always be idempotent. I thought it would fix some actual bugs in behavior but I was unable to "trick" the existing loader into double-loading a requires line even though I tried installing and activating gems after having already required system libs. Since I couldn't find any bugs, though, that also means that this should be backwards compatible with existing behavior.

An strace of the process of a single require "openssl", after it has been already required looks like this:

open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/uuidtools-2.1.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/chef-bin-15.0.276/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/public_suffix-3.0.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/addressable-2.6.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/mixlib-shellout-2.4.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/mixlib-cli-2.0.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/appbundler-0.12.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/bcrypt_pbkdf-1.0.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/bcrypt_pbkdf-1.0.1/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/debug_inspector-0.0.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/debug_inspector-0.0.3/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/binding_of_caller-0.8.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/binding_of_caller-0.8.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/builder-3.2.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/byebug-11.0.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/byebug-11.0.1/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tomlrb-1.2.8/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/mixlib-config-3.0.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/fuzzyurl-0.9.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/chef-config-15.0.276/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/net-ssh-5.2.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/net-scp-2.0.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/erubis-2.7.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ffi-1.10.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/ffi-1.10.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/gssapi-1.3.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/gyoku-1.3.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/httpclient-2.8.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/little-plugger-1.1.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/multi_json-1.13.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/logging-2.2.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/nori-2.6.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rubyntlm-0.6.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/winrm-2.3.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rubyzip-1.2.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/winrm-fs-1.3.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/train-core-2.1.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/equatable-0.5.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tty-color-0.4.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/pastel-0.7.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tty-cursor-0.6.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/strings-ansi-0.1.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/unicode_utils-1.4.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/unicode-display_width-1.4.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/strings-0.1.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tty-box-0.3.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/necromancer-0.4.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/timers-4.3.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/wisper-2.0.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tty-screen-0.6.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tty-reader-0.5.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tty-prompt-0.18.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/license-acceptance-1.0.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/mixlib-log-3.0.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/mixlib-authentication-2.1.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/mixlib-archive-1.0.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/systemu-2.6.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/libyajl2-1.2.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/libyajl2-1.2.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ffi-yajl-2.3.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/ffi-yajl-2.3.1/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/plist-3.5.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ipaddress-0.8.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/wmi-lite-1.0.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ohai-15.0.34/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/net-ssh-gateway-2.0.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/net-ssh-multi-1.2.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/net-sftp-2.1.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ed25519-1.2.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/ed25519-1.2.4/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/highline-1.7.10/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/diff-lcs-1.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ffi-libarchive-0.4.6/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/hashie-3.6.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/uuidtools-2.1.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/chef-zero-14.0.12/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/iniparse-1.4.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/syslog-logger-1.6.8/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/proxifier-1.0.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/chef-15.0.276/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/chef-bin-15.0.276/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/chef-vault-3.4.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/cheffish-14.0.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/coderay-1.1.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/safe_yaml-1.0.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/crack-0.4.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/docile-1.3.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/multipart-post-2.0.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/faraday-0.15.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/faraday_middleware-0.12.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/hashdiff-0.3.9/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/htmlentities-4.3.4/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/thor-0.20.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/method_source-0.9.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rspec-support-3.8.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rspec-core-3.8.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rspec-expectations-3.8.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rspec-mocks-3.8.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rspec-3.8.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rspec-its-1.3.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/pry-0.12.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/sslshake-1.3.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/parallel-1.17.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/parslet-1.8.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/semverse-3.0.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tty-table-0.10.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/tins-1.20.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/term-ansicolor-1.7.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/inspec-core-4.3.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/json-2.2.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/json-2.2.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/pry-byebug-3.7.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/slop-3.6.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/pry-remote-0.1.8/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/pry-stack_explorer-0.4.9.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rake-12.3.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rb-readline-0.5.5/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/rspec_junit_formatter-0.2.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ruby-prof-0.17.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/ruby-prof-0.17.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/ruby-shadow-2.5.0/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/extensions/x86_64-linux/2.6.0/ruby-shadow-2.5.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/simplecov-html-0.10.2/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/simplecov-0.16.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/webmock-3.5.1/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/gems/2.6.0/gems/bundler-1.17.3/lib/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/site_ruby/2.6.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/site_ruby/2.6.0/x86_64-linux/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/site_ruby/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/vendor_ruby/2.6.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/vendor_ruby/2.6.0/x86_64-linux/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/vendor_ruby/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/opt/chef/embedded/lib/ruby/2.6.0/openssl.rb", O_RDONLY|O_NONBLOCK|O_CLOEXEC) = 7

On windows, taking this much I/O on every single require line, can quickly add up to 100,000s of open calls, which takes several seconds on an SSD and can take upwards of a minute on a spinning drive just to evaluate the requires of an application that does no work (i.e. command line tooling).

History

#1 [ruby-core:92690]

Updated by hsbt (Hiroshi SHIBATA) 3 months ago

Assignee set to hsbt (Hiroshi SHIBATA)
Status changed from Open to Assigned

ref. https://github.com/rubygems/rubygems/issues/2762

#2 [ruby-core:92730]

Updated by deivid (David Rodríguez) 3 months ago

I had a look at this. I manage to reproduce the issue only when requiring openssl. In general, I think it can be reproduced when a ruby feature requires an dynamic library of the same name. In this case, require "openssl" resolves to requiring openssl.rb, which internally requires (among other stuff) openssl.so.

To reproduce, I required openssl a lot of times, expecting that after the first time the require would have no overhead. However,

$ time ruby --disable-gems -e '100000.times { require "openssl" }'

real    0m3,075s
user    0m1,732s
sys     0m1,301s

The problem can be workaround by explicitly specifying the file extension

$ time ruby --disable-gems -e '100000.times { require "openssl.rb" }'

real    0m0,137s
user    0m0,113s
sys     0m0,029s

I took a lot at fixing it and came up with this patch

diff --git a/load.c b/load.c
index 576464fb68..ae89f63820 100644
--- a/load.c
+++ b/load.c
@@ -908,6 +908,11 @@ search_required(VALUE fname, volatile VALUE *path, int safe_level, feature_func
        if (loading) *path = rb_filesystem_str_new_cstr(loading);
        return 'r';
     }
+    else if ((ft = rb_feature_p(ftptr, 0, FALSE, FALSE, &loading)) == 's') {
+       if (loading) *path = rb_filesystem_str_new_cstr(loading);
+       return 's';
+    }
+
     tmp = fname;
     type = rb_find_file_ext_safe(&tmp, loadable_ext, safe_level);
     switch (type) {

However, that breaks the following spec:

it "loads a .rb extensioned file when a C-extension file of the same name is loaded" do
  $LOADED_FEATURES << File.expand_path("load_fixture.bundle", CODE_LOADING_DIR)
  $LOADED_FEATURES << File.expand_path("load_fixture.dylib", CODE_LOADING_DIR)
  $LOADED_FEATURES << File.expand_path("load_fixture.so", CODE_LOADING_DIR)
  $LOADED_FEATURES << File.expand_path("load_fixture.dll", CODE_LOADING_DIR)
  path = File.expand_path "load_fixture", CODE_LOADING_DIR
  @object.require(path).should be_true
  ScratchPad.recorded.should == [:loaded]
end

I'm not sure that spec is expected behavior, though. It was introduced during this refactoring, but I think the refactoring changed the expectations, because the previous spec I think this spec comes from reads like this:

it "will load file.rb when given 'file' if it exists even if file.<ext> is loaded" do
  $LOADED_FEATURES << "require_spec_3.#{Config::CONFIG['DLEXT']}"
  require('require_spec_3.rb').should be_true
  $LOADED_FEATURES.grep(/require_spec_3\.rb/).should_not == []
end

and while the description is what the spec tests nowadays, the implementation explictly included a file extension (require_spec_3.rb), while the current spec does not (load_fixture).

Essentially I think it comes down to whether the correct behavior is the current one:

$ ruby --disable-gems -e 'puts require "openssl.so"; puts require "openssl"'
true
true

or the one after my patch:

$ ruby --disable-gems -e 'puts require "openssl.so"; puts require "openssl"'
true
false

If the expected behavior is the current one, then obviously my patch doesn't work.

#3 [ruby-core:92749]

Updated by lamont (Lamont Granquist) 3 months ago

Okay that explains what I was seeing, I just didn't realize that it was that subtle around .so loading, but I think I've verified that this is for those native libraries only.

I'd argue that your patch results in more correct and less surprising behavior, but I have no idea who is bug dependent upon it.

I'm going to wind up doing a large amount of work to bypass this problem, though, and decorating all our code with require "openssl" unless defined?(OpenSSL) old-school tactics from 8+ years ago as a workaround. I would definitely vote to change this behavior in core.

And I've already had users reading my code patches and I'm worried about I'm about to start a cargo cult of how to make ruby go fast.

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