1 files changed, 49 insertions, 0 deletions
diff --git a/test/ruby/lbtest.rb b/test/ruby/lbtest.rb
new file mode 100644
index 0000000000..c7822c9e9a
--- /dev/null
+++ b/test/ruby/lbtest.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: false
+
+class LocalBarrier
+  def initialize(n)
+    @wait = Thread::Queue.new
+    @done = Thread::Queue.new
+    @keeper = begin_keeper(n)
+  end
+
+  def sync
+    @done.push(true)
+    @wait.pop
+  end
+
+  def join
+    @keeper.join
+  end
+
+  private
+  def begin_keeper(n)
+    Thread.start do
+      n.times do
+        @done.pop
+      end
+      n.times do
+        @wait.push(true)
+      end
+    end
+  end
+end
+
+n = 10
+
+lb = LocalBarrier.new(n)
+
+(n - 1).times do |i|
+  Thread.start do
+    sleep((rand(n) + 1) / 100.0)
+    print "#{i}: done\n"
+    lb.sync
+    print "#{i}: cont\n"
+  end
+end
+
+lb.sync
+print "#{n-1}: cont\n"
+# lb.join # [ruby-dev:30653]
+
+print "exit.\n"