1 files changed, 153 insertions, 0 deletions
diff --git a/lib/thread.rb b/lib/thread.rb
new file mode 100644
index 0000000000..c3347b60b4
--- /dev/null
+++ b/lib/thread.rb
@@ -0,0 +1,153 @@
+#
+#		thread.rb - thread support classes
+#			$Date: 1996/05/21 09:29:21 $
+#			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
+    Thread.exclusive do
+      if not @locked
+	@locked=TRUE
+	return TRUE
+      end
+    end
+    FALSE
+  end
+
+  def lock
+    while not try_lock
+      @waiting.push Thread.current
+      Thread.stop
+    end
+  end
+
+  def unlock
+    @locked = FALSE
+    if w = @waiting.shift
+      w.run
+    end
+  end
+
+  def synchronize
+    begin
+      lock
+      yield
+    ensure
+      unlock
+    end
+  end
+end
+
+class SharedMutex<Mutex
+  def initialize
+    @locking = nil
+    @num_locks = 0;
+    super
+  end
+  def try_lock
+    if @locking == Thread.current
+      @num_locks += 1
+      return TRUE
+    end
+    if super
+      @num_locks = 1
+      @locking = Thread.current
+      TRUE
+    else
+      FALSE
+    end
+  end
+  def unlock
+    unless @locking == Thread.current
+      raise ThreadError, "cannot release shared mutex"
+    end
+    @num_locks -= 1
+    if @num_locks == 0
+      @locking = nil
+      super
+    end
+  end
+end
+
+class Queue
+  def initialize
+    @que = []
+    @waiting = []
+  end
+
+  def push(obj)
+    @que.push obj
+    if t = @waiting.shift
+      t.run
+    end
+  end
+
+  def pop non_block=FALSE
+    if @que.length == 0
+      raise ThreadError, "queue empty" if non_block
+      @waiting.push Thread.current
+      Thread.stop
+    end
+    @que.shift
+  end
+
+  def empty?
+    @que.length == 0
+  end
+
+  def length
+    @que.length
+  end
+end
+
+class Condition
+  def initialize
+    @waiting = []
+  end
+
+  def wait(mut)
+    Thread.exclusive do
+      mut.unlock
+      @waiting.push Thread.current
+    end
+    Thread.sleep
+    mut.lock
+  end
+
+  def signal
+    th = nil
+    Thread.exclusive do
+      th = @waiting.pop
+    end
+    th.run
+  end
+
+  def broadcast
+    w = @waiting
+    Thread.exclusive do
+      th = []
+    end
+    for th in w
+      th.run
+    end
+  end
+end