Improve the event_catcher_spec by using a Latch

spec/event_catcher_spec.rb

@@ -4,21 +4,22 @@
 describe EventCatcher do
   subject { EventCatcher.new }
 
+  let!(:latch) { Latch.new }
+
   describe :wait_for do
     it %[should wake when an event is delivered] do
-      pending "this has a pretty awful race in it"
 
       th = Thread.new do
         subject.synchronize do
           logger.debug { "about to wait for created" }
+          latch.release
           subject.wait_for_created
           logger.debug { "woke up, created must have been delivered" }
         end
         true
       end
 
-      th.run
-      Thread.pass until th.status == 'sleep'
+      latch.await
 
       logger.debug { "th.status: #{th.status}" }
 

spec/support/event_catcher.rb

@@ -64,15 +64,15 @@ def cond_#{name}
 
       # waits for an event group to not be empty (up to timeout sec)
       def wait_for_#{name}(timeout=5)
-        cond(:#{name}).wait(timeout)
+        wait_for(:#{name}, timeout)
       end
 
-      def wait_while_#{name}
-        cond(:#{name}).wait_while { yield __send__(:#{name}) }
+      def wait_while_#{name}(&blk)
+        wait_while(:#{name}, &blk)
       end
 
-      def wait_until_#{name}
-        cond(:#{name}).wait_until { yield __send__(:#{name}) }
+      def wait_until_#{name}(&blk)
+        wait_until(:#{name}, &blk)
       end
     EOS
   end

spec/support/latch.rb

@@ -0,0 +1,23 @@
+# the much fabled 'latch' that tenderlove and nahi were on about
+
+class Latch
+  def initialize(count = 1)
+    @count = count
+    @mutex = Monitor.new
+    @cond = @mutex.new_cond
+  end
+
+  def release
+    @mutex.synchronize {
+      @count -= 1 if @count > 0
+      @cond.broadcast if @count.zero?
+    }
+  end
+
+  def await
+    @mutex.synchronize {
+      @cond.wait_while { @count > 0 }
+    }
+  end
+end
+