don't run thread specs as part of the CI build.

Rakefile

@@ -16,7 +16,7 @@ end
 
 require 'rspec/core/rake_task'
 RSpec::Core::RakeTask.new(:spec) do |task|
-  task.rspec_opts = '--tag ~memory'
+  task.rspec_opts = '--tag ~memory --tag ~threads'
 end
 
 task :sanity => [:clean, :compile] do

spec/threading_spec.rb

@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe "using v8 from multiple threads" do
+describe "using v8 from multiple threads", :threads => true do
 
   it "creates contexts from within threads" do
     10.times.collect do
@@ -21,4 +21,32 @@ describe "using v8 from multiple threads" do
       end
     end.each {|t| t.join}
   end
+
+  it "can access the current thread id" do
+    V8::C::Locker() do
+      V8::C::V8::GetCurrentThreadId().should_not be_nil
+    end
+  end
+
+  it "can pre-empt a running JavaScript thread" do
+    pending "need to release the GIL while executing V8 code"
+    begin
+      V8::C::Locker::StartPreemption(2)
+      thread_id = nil
+      Thread.new do
+        loop until thread_id
+        puts "thread id: #{thread_id}"
+        V8::C::V8::TerminateExecution(thread_id)
+      end
+      Thread.new do
+        V8::C::Locker() do
+          thread_id = V8::C::V8::GetCurrentThreadId()
+          V8::Context.new {|cxt| cxt.eval('while (true) {}')}
+        end
+      end
+      V8::C::V8::TerminateExecution(thread_id)
+    ensure
+      V8::C::Locker::StopPreemption()
+    end
+  end
 end