Sync was extracted from std lib in ruby 2.7

[jrafanie]

Add the gem for forward compatibility.

Found in #19678

[miq-bot]

Checked commit jrafanie@84be676 with ruby 2.5.5, rubocop 0.69.0, haml-lint 0.20.0, and yamllint 1.10.0
1 file checked, 0 offenses detected
Everything looks fine. 🍰

[Fryguy]

My only concern, that I can't tell from this PR, is whether or not sync 0.5.0 is what is being used in Ruby 2.5 / 2.6. If we are supporting multiple Rubies, should this line be postfixed with if RUBY_VERSION >= "2.7" or something to that effect?

[jrafanie]

My only concern, that I can't tell from this PR, is whether or not sync 0.5.0 is what is being used in Ruby 2.5 / 2.6. If we are supporting multiple Rubies, should this line be postfixed with if RUBY_VERSION >= "2.7" or something to that effect?

Great question. I forgot to mention that sync hasn't been changed in years. It looks like they just bumped the version to 0.5.0 and extracted it to a gem at that version:

02:43:59 ~/Code/ruby ((650c45dcd7...)) (2.5.7) + git diff upstream/ruby_2_5 upstream/ruby_2_6 lib/sync.rb
diff --git a/lib/sync.rb b/lib/sync.rb
index 40a48ac985..998e2b7b92 100644
--- a/lib/sync.rb
+++ b/lib/sync.rb
@@ -38,10 +38,6 @@
 #
 #

-unless defined? Thread
-  raise "Thread not available for this ruby interpreter"
-end
-
 ##
 # A module that provides a two-phase lock with a counter.

@@ -320,6 +316,9 @@ def sync_try_lock_sub(m)
 # details.

 class Sync
+
+  VERSION = "0.5.0"
+
   include Sync_m
 end

[djberg96]

👍