When setting current thread scheduler to nil, invoke `#close`.

2 files changed, 40 insertions, 0 deletions

diff --git a/test/fiber/scheduler.rb b/test/fiber/scheduler.rb
index 43edcb27ed..10854aac2c 100644
--- a/test/fiber/scheduler.rb
+++ b/test/fiber/scheduler.rb
@@ -19,6 +19,8 @@ class Scheduler
     @writable = {}
     @waiting = {}
 
+    @closed = false
+
     @lock = Mutex.new
     @locking = 0
     @ready = []
@@ -96,6 +98,19 @@ class Scheduler
     @urgent = nil
   end
 
+  def close
+    self.run
+  ensure
+    @closed = true
+    
+    # We freeze to detect any inadvertant modifications after the scheduler is closed:
+    self.freeze
+  end
+
+  def closed?
+    @closed
+  end
+
   def current_time
     Process.clock_gettime(Process::CLOCK_MONOTONIC)
   end
diff --git a/test/fiber/test_scheduler.rb b/test/fiber/test_scheduler.rb
index 7acf63d9b8..23fd8b4493 100644
--- a/test/fiber/test_scheduler.rb
+++ b/test/fiber/test_scheduler.rb
@@ -10,4 +10,29 @@ class TestFiberScheduler < Test::Unit::TestCase
       end
     end
   end
+  
+  def test_closed_at_thread_exit
+    scheduler = Scheduler.new
+
+    thread = Thread.new do
+      Thread.current.scheduler = scheduler
+    end
+
+    thread.join
+
+    assert scheduler.closed?
+  end
+
+  def test_closed_when_set_to_nil
+    scheduler = Scheduler.new
+
+    thread = Thread.new do
+      Thread.current.scheduler = scheduler
+      Thread.current.scheduler = nil
+
+      assert scheduler.closed?
+    end
+
+    thread.join
+  end
 end