1 files changed, 110 insertions, 0 deletions
diff --git a/lib/thread.rb b/lib/thread.rb
new file mode 100644
index 0000000000..4f294cc9a3
--- /dev/null
+++ b/lib/thread.rb
@@ -0,0 +1,110 @@
+#
+#		thread.rb - thread support classes
+#			$Date$
+#			by Yukihiro Matsumoto <matz@caelum.co.jp>
+#
+
+unless defined? Thread
+  fail "Thread not available for this ruby interpreter"
+end
+
+unless defined? ThreadError
+  class ThreadError<Exception
+  end
+end
+
+class Mutex
+  def initialize
+    @waiting = []
+    @locked = FALSE;
+  end
+
+  def locked?
+    @locked
+  end
+
+  def try_lock
+    result = FALSE
+    Thread.critical = TRUE
+    unless @locked
+      @locked = TRUE
+      result = TRUE
+    end
+    Thread.critical = FALSE
+    result
+  end
+
+  def lock
+    while (Thread.critical = TRUE; @locked)
+      @waiting.push Thread.current
+      Thread.stop
+    end
+    @locked = TRUE
+    Thread.critical = FALSE
+    self
+  end
+
+  def unlock
+    return unless @locked
+    Thread.critical = TRUE
+    wait = @waiting
+    @waiting = []
+    @locked = FALSE
+    Thread.critical = FALSE
+    for w in wait
+      w.run
+    end
+    self
+  end
+
+  def synchronize
+    begin
+      lock
+      yield
+    ensure
+      unlock
+    end
+  end
+end
+
+class Queue
+  def initialize
+    @que = []
+    @waiting = []
+  end
+
+  def push(obj)
+    Thread.critical = TRUE
+    @que.push obj
+    t = @waiting.shift
+    Thread.critical = FALSE
+    t.run if t
+  end
+
+  def pop non_block=FALSE
+    item = nil
+    until item
+      Thread.critical = TRUE
+      if @que.length == 0
+	if non_block
+	  Thread.critical = FALSE
+	  raise ThreadError, "queue empty"
+	end
+	@waiting.push Thread.current
+	Thread.stop
+      else
+	item = @que.shift
+      end
+    end
+    Thread.critical = FALSE
+    item
+  end
+
+  def empty?
+    @que.length == 0
+  end
+
+  def length
+    @que.length
+  end
+end