merge revision(s) a8c2d5e7bee5fad0965baeb58d312ddc5932ec26: [Backport #20907]

	Ensure fiber scheduler re-acquires mutex when interrupted from sleep. (#12158)

	[Bug #20907]

1 files changed, 28 insertions, 0 deletions

diff --git a/test/fiber/test_scheduler.rb b/test/fiber/test_scheduler.rb
index f8993bb18f..98f20e1c58 100644
--- a/test/fiber/test_scheduler.rb
+++ b/test/fiber/test_scheduler.rb
@@ -182,4 +182,32 @@ class TestFiberScheduler < Test::Unit::TestCase
     thread.join
     signaller.join
   end
+
+  def test_condition_variable
+    condition_variable = ::Thread::ConditionVariable.new
+    mutex = ::Thread::Mutex.new
+
+    error = nil
+
+    thread = Thread.new do
+      Thread.current.report_on_exception = false
+
+      scheduler = Scheduler.new
+      Fiber.set_scheduler scheduler
+
+      fiber = Fiber.schedule do
+        begin
+          mutex.synchronize do
+            condition_variable.wait(mutex)
+          end
+        rescue => error
+        end
+      end
+
+      fiber.raise(RuntimeError)
+    end
+
+    thread.join
+    assert_kind_of RuntimeError, error
+  end
 end