1 files changed, 31 insertions, 11 deletions
diff --git a/test/fiber/test_mutex.rb b/test/fiber/test_mutex.rb
index 0842427760..2cee2cc235 100644
--- a/test/fiber/test_mutex.rb
+++ b/test/fiber/test_mutex.rb
@@ -4,7 +4,7 @@ require_relative 'scheduler'
 
 class TestFiberMutex < Test::Unit::TestCase
   def test_mutex_synchronize
-    mutex = Mutex.new
+    mutex = Thread::Mutex.new
 
     thread = Thread.new do
       scheduler = Scheduler.new
@@ -23,7 +23,7 @@ class TestFiberMutex < Test::Unit::TestCase
   end
 
   def test_mutex_interleaved_locking
-    mutex = Mutex.new
+    mutex = Thread::Mutex.new
 
     thread = Thread.new do
       scheduler = Scheduler.new
@@ -48,7 +48,7 @@ class TestFiberMutex < Test::Unit::TestCase
   end
 
   def test_mutex_thread
-    mutex = Mutex.new
+    mutex = Thread::Mutex.new
     mutex.lock
 
     thread = Thread.new do
@@ -71,7 +71,7 @@ class TestFiberMutex < Test::Unit::TestCase
   end
 
   def test_mutex_fiber_raise
-    mutex = Mutex.new
+    mutex = Thread::Mutex.new
     ran = false
 
     main = Thread.new do
@@ -103,8 +103,8 @@ class TestFiberMutex < Test::Unit::TestCase
   end
 
   def test_condition_variable
-    mutex = Mutex.new
-    condition = ConditionVariable.new
+    mutex = Thread::Mutex.new
+    condition = Thread::ConditionVariable.new
 
     signalled = 0
 
@@ -138,7 +138,7 @@ class TestFiberMutex < Test::Unit::TestCase
   end
 
   def test_queue
-    queue = Queue.new
+    queue = Thread::Queue.new
     processed = 0
 
     thread = Thread.new do
@@ -169,7 +169,7 @@ class TestFiberMutex < Test::Unit::TestCase
   end
 
   def test_queue_pop_waits
-    queue = Queue.new
+    queue = Thread::Queue.new
     running = false
 
     thread = Thread.new do
@@ -194,11 +194,11 @@ class TestFiberMutex < Test::Unit::TestCase
   end
 
   def test_mutex_deadlock
-    error_pattern = /No live threads left. Deadlock\?/
+    error_pattern = /lock already owned by another fiber/
 
     assert_in_out_err %W[-I#{__dir__} -], <<-RUBY, ['in synchronize'], error_pattern, success: false
     require 'scheduler'
-    mutex = Mutex.new
+    mutex = Thread::Mutex.new
 
     thread = Thread.new do
       scheduler = Scheduler.new
@@ -207,7 +207,7 @@ class TestFiberMutex < Test::Unit::TestCase
       Fiber.schedule do
         mutex.synchronize do
           puts 'in synchronize'
-          Fiber.yield
+          scheduler.transfer
         end
       end
 
@@ -217,4 +217,24 @@ class TestFiberMutex < Test::Unit::TestCase
     thread.join
     RUBY
   end
+
+  def test_mutex_fiber_deadlock_no_scheduler
+    thr = Thread.new do
+      loop do
+        sleep 1
+      end
+    end
+
+    mutex = Mutex.new
+    mutex.synchronize do
+      error = assert_raise ThreadError do
+        Fiber.new do
+          mutex.lock
+        end.resume
+      end
+      assert_includes error.message, "deadlock; lock already owned by another fiber belonging to the same thread"
+    end
+  ensure
+    thr&.kill&.join
+  end
 end