[ruby/spec] Don't care about return values

RDoc says nothing about them.  Added an example that
ConditionVariable#wait can be woken up by
ConditionVariable#signal, instead.

spec/ruby/library/conditionvariable/broadcast_spec.rb

@@ -2,33 +2,6 @@ require_relative '../../spec_helper'
 require 'thread'
 
 describe "ConditionVariable#broadcast" do
-  it "returns self if nothing to broadcast to" do
-    cv = ConditionVariable.new
-    cv.broadcast.should == cv
-  end
-
-  it "returns self if something is waiting for a broadcast" do
-    m = Mutex.new
-    cv = ConditionVariable.new
-    in_synchronize = false
-
-    th = Thread.new do
-      m.synchronize do
-        in_synchronize = true
-        cv.wait(m)
-      end
-    end
-
-    # wait for m to acquire the mutex
-    Thread.pass until in_synchronize
-    # wait until th is sleeping (ie waiting)
-    Thread.pass until th.stop?
-
-    m.synchronize { cv.broadcast }.should == cv
-
-    th.join
-  end
-
   it "releases all threads waiting in line for this resource" do
     m = Mutex.new
     cv = ConditionVariable.new

spec/ruby/library/conditionvariable/signal_spec.rb

@@ -2,33 +2,6 @@ require_relative '../../spec_helper'
 require 'thread'
 
 describe "ConditionVariable#signal" do
-  it "returns self if nothing to signal" do
-    cv = ConditionVariable.new
-    cv.signal.should == cv
-  end
-
-  it "returns self if something is waiting for a signal" do
-    m = Mutex.new
-    cv = ConditionVariable.new
-    in_synchronize = false
-
-    th = Thread.new do
-      m.synchronize do
-        in_synchronize = true
-        cv.wait(m)
-      end
-    end
-
-    # wait for m to acquire the mutex
-    Thread.pass until in_synchronize
-    # wait until th is sleeping (ie waiting)
-    Thread.pass until th.stop?
-
-    m.synchronize { cv.signal }.should == cv
-
-    th.join
-  end
-
   it "releases the first thread waiting in line for this resource" do
     m = Mutex.new
     cv = ConditionVariable.new

spec/ruby/library/conditionvariable/wait_spec.rb

@@ -11,7 +11,7 @@ describe "ConditionVariable#wait" do
     cv.wait(o, 1234)
   end
 
-  it "returns self" do
+  it "can be woken up by ConditionVariable#signal" do
     m = Mutex.new
     cv = ConditionVariable.new
     in_synchronize = false
@@ -19,8 +19,9 @@ describe "ConditionVariable#wait" do
     th = Thread.new do
       m.synchronize do
         in_synchronize = true
-        cv.wait(m).should == cv
+        cv.wait(m)
       end
+      :success
     end
 
     # wait for m to acquire the mutex
@@ -29,7 +30,7 @@ describe "ConditionVariable#wait" do
     Thread.pass until th.stop?
 
     m.synchronize { cv.signal }
-    th.join
+    th.value.should == :success
   end
 
   it "can be interrupted by Thread#run" do