6 files changed, 40 insertions, 45 deletions
diff --git a/spec/ruby/core/threadgroup/add_spec.rb b/spec/ruby/core/threadgroup/add_spec.rb
index 4320f7ba30..2921c1ab22 100644
--- a/spec/ruby/core/threadgroup/add_spec.rb
+++ b/spec/ruby/core/threadgroup/add_spec.rb
@@ -1,36 +1,39 @@
 require_relative '../../spec_helper'
-require_relative 'fixtures/classes'
 
 describe "ThreadGroup#add" do
   before :each do
-    @chan1,@chan2 = Channel.new,Channel.new
-    @thread = Thread.new { @chan1 << :go; @chan2.receive }
-    @chan1.receive
+    @q1, @q2 = Queue.new, Queue.new
+    @thread = Thread.new { @q1 << :go; @q2.pop }
+    @q1.pop
   end
 
   after :each do
-    @chan2 << :done
+    @q2 << :done
     @thread.join
   end
 
-  it "adds the given thread to a group and returns self" do
-    @thread.group.should_not == nil
+  # This spec randomly kills mspec worker like: https://ci.appveyor.com/project/ruby/ruby/build/9806/job/37tx2atojy96227m
+  # TODO: Investigate the cause or at least print helpful logs, and remove this `platform_is_not` guard.
+  platform_is_not :mingw do
+    it "adds the given thread to a group and returns self" do
+      @thread.group.should_not == nil
 
-    tg = ThreadGroup.new
-    tg.add(@thread).should == tg
-    @thread.group.should == tg
-    tg.list.include?(@thread).should == true
-  end
+      tg = ThreadGroup.new
+      tg.add(@thread).should == tg
+      @thread.group.should == tg
+      tg.list.include?(@thread).should == true
+    end
 
-  it "removes itself from any other threadgroup" do
-    tg1 = ThreadGroup.new
-    tg2 = ThreadGroup.new
+    it "removes itself from any other threadgroup" do
+      tg1 = ThreadGroup.new
+      tg2 = ThreadGroup.new
 
-    tg1.add(@thread)
-    @thread.group.should == tg1
-    tg2.add(@thread)
-    @thread.group.should == tg2
-    tg2.list.include?(@thread).should == true
-    tg1.list.include?(@thread).should == false
+      tg1.add(@thread)
+      @thread.group.should == tg1
+      tg2.add(@thread)
+      @thread.group.should == tg2
+      tg2.list.include?(@thread).should == true
+      tg1.list.include?(@thread).should == false
+    end
   end
 end
diff --git a/spec/ruby/core/threadgroup/default_spec.rb b/spec/ruby/core/threadgroup/default_spec.rb
index d7d4726cc2..4f57508abf 100644
--- a/spec/ruby/core/threadgroup/default_spec.rb
+++ b/spec/ruby/core/threadgroup/default_spec.rb
@@ -2,7 +2,7 @@ require_relative '../../spec_helper'
 
 describe "ThreadGroup::Default" do
   it "is a ThreadGroup instance" do
-    ThreadGroup::Default.should be_kind_of(ThreadGroup)
+    ThreadGroup::Default.should.is_a?(ThreadGroup)
   end
 
   it "is the ThreadGroup of the main thread" do
diff --git a/spec/ruby/core/threadgroup/enclose_spec.rb b/spec/ruby/core/threadgroup/enclose_spec.rb
index d4a4359c66..6f703d4ce2 100644
--- a/spec/ruby/core/threadgroup/enclose_spec.rb
+++ b/spec/ruby/core/threadgroup/enclose_spec.rb
@@ -1,15 +1,14 @@
 require_relative '../../spec_helper'
-require_relative 'fixtures/classes'
 
 describe "ThreadGroup#enclose" do
   before :each do
-    @chan1,@chan2 = Channel.new,Channel.new
-    @thread = Thread.new { @chan1 << :go; @chan2.receive }
-    @chan1.receive
+    @q1, @q2 = Queue.new, Queue.new
+    @thread = Thread.new { @q1 << :go; @q2.pop }
+    @q1.pop
   end
 
   after :each do
-    @chan2 << :done
+    @q2 << :done
     @thread.join
   end
 
@@ -18,8 +17,8 @@ describe "ThreadGroup#enclose" do
     default_group = @thread.group
     thread_group.add(@thread)
     thread_group.enclose
-    lambda do
+    -> do
       default_group.add(@thread)
-    end.should raise_error(ThreadError)
+    end.should.raise(ThreadError)
   end
 end
diff --git a/spec/ruby/core/threadgroup/enclosed_spec.rb b/spec/ruby/core/threadgroup/enclosed_spec.rb
index a734256a64..cf8a5bb4c6 100644
--- a/spec/ruby/core/threadgroup/enclosed_spec.rb
+++ b/spec/ruby/core/threadgroup/enclosed_spec.rb
@@ -3,12 +3,12 @@ require_relative '../../spec_helper'
 describe "ThreadGroup#enclosed?" do
   it "returns false when a ThreadGroup has not been enclosed (default state)" do
     thread_group = ThreadGroup.new
-    thread_group.enclosed?.should be_false
+    thread_group.enclosed?.should == false
   end
 
   it "returns true when a ThreadGroup is enclosed" do
     thread_group = ThreadGroup.new
     thread_group.enclose
-    thread_group.enclosed?.should be_true
+    thread_group.enclosed?.should == true
   end
 end
diff --git a/spec/ruby/core/threadgroup/fixtures/classes.rb b/spec/ruby/core/threadgroup/fixtures/classes.rb
deleted file mode 100644
index 7dfe5e92d1..0000000000
--- a/spec/ruby/core/threadgroup/fixtures/classes.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-unless defined? Channel
-  require 'thread'
-  class Channel < Queue
-    alias receive shift
-  end
-end
diff --git a/spec/ruby/core/threadgroup/list_spec.rb b/spec/ruby/core/threadgroup/list_spec.rb
index 5f2281af8d..ef601d75ea 100644
--- a/spec/ruby/core/threadgroup/list_spec.rb
+++ b/spec/ruby/core/threadgroup/list_spec.rb
@@ -1,20 +1,19 @@
 require_relative '../../spec_helper'
-require_relative 'fixtures/classes'
 
 describe "ThreadGroup#list" do
   it "returns the list of threads in the group" do
-    chan = Channel.new
-    th1 = Thread.new { chan << :go; sleep }
-    chan.receive.should == :go
+    q = Queue.new
+    th1 = Thread.new { q << :go; sleep }
+    q.pop.should == :go
     tg = ThreadGroup.new
     tg.add(th1)
-    tg.list.should include(th1)
+    tg.list.should.include?(th1)
 
-    th2 = Thread.new { chan << :go; sleep }
-    chan.receive.should == :go
+    th2 = Thread.new { q << :go; sleep }
+    q.pop.should == :go
 
     tg.add(th2)
-    (tg.list & [th1, th2]).should include(th1, th2)
+    (tg.list & [th1, th2]).to_set.should == Set[th1, th2]
 
     Thread.pass while th1.status and th1.status != 'sleep'
     Thread.pass while th2.status and th2.status != 'sleep'