1 files changed, 111 insertions, 20 deletions

diff --git a/lib/thread.rb b/lib/thread.rb
index 4f294cc9a3..91c588f603 100644
--- a/lib/thread.rb
+++ b/lib/thread.rb
@@ -13,10 +13,14 @@ unless defined? ThreadError
   end
 end
 
+if $DEBUG
+  Thread.abort_on_exception = true
+end
+
 class Mutex
   def initialize
     @waiting = []
-    @locked = FALSE;
+    @locked = false;
   end
 
   def locked?
@@ -24,36 +28,33 @@ class Mutex
   end
 
   def try_lock
-    result = FALSE
-    Thread.critical = TRUE
+    result = false
+    Thread.critical = true
     unless @locked
-      @locked = TRUE
-      result = TRUE
+      @locked = true
+      result = true
     end
-    Thread.critical = FALSE
+    Thread.critical = false
     result
   end
 
   def lock
-    while (Thread.critical = TRUE; @locked)
+    while (Thread.critical = true; @locked)
       @waiting.push Thread.current
       Thread.stop
     end
-    @locked = TRUE
-    Thread.critical = FALSE
+    @locked = true
+    Thread.critical = false
     self
   end
 
   def unlock
     return unless @locked
     Thread.critical = TRUE
-    wait = @waiting
-    @waiting = []
+    t = @waiting.shift
     @locked = FALSE
     Thread.critical = FALSE
-    for w in wait
-      w.run
-    end
+    t.run if t
     self
   end
 
@@ -67,6 +68,38 @@ class Mutex
   end
 end
 
+class ConditionVariable
+  def initialize
+    @waiters = []
+    @waiters_mutex = Mutex.new
+  end
+  
+  def wait(mutex)
+    mutex.unlock
+    @waiters_mutex.synchronize {
+      @waiters.push(Thread.current)
+    }
+    Thread.stop
+    mutex.lock
+  end
+  
+  def signal
+    @waiters_mutex.synchronize {
+      t = @waiters.shift
+      t.run if t
+    }
+  end
+    
+  def broadcast
+    @waiters_mutex.synchronize {
+      for t in @waiters
+	t.run
+      end
+      @waiters.clear
+    }
+  end
+end
+
 class Queue
   def initialize
     @que = []
@@ -74,20 +107,20 @@ class Queue
   end
 
   def push(obj)
-    Thread.critical = TRUE
+    Thread.critical = true
     @que.push obj
     t = @waiting.shift
-    Thread.critical = FALSE
+    Thread.critical = false
     t.run if t
   end
 
-  def pop non_block=FALSE
+  def pop non_block=false
     item = nil
     until item
-      Thread.critical = TRUE
+      Thread.critical = true
       if @que.length == 0
 	if non_block
-	  Thread.critical = FALSE
+	  Thread.critical = false
 	  raise ThreadError, "queue empty"
 	end
 	@waiting.push Thread.current
@@ -96,7 +129,7 @@ class Queue
 	item = @que.shift
       end
     end
-    Thread.critical = FALSE
+    Thread.critical = false
     item
   end
 
@@ -107,4 +140,62 @@ class Queue
   def length
     @que.length
   end
+  alias size length
+
+
+  def num_waiting
+    @waiting.size
+  end
+end
+
+class SizedQueue<Queue
+  def initialize(max)
+    @max = max
+    @queue_wait = []
+    super()
+  end
+
+  def max
+    @max
+  end
+
+  def max=(max)
+    Thread.critical = TRUE
+    if @max >= max
+      @max = max
+      Thread.critical = FALSE
+    else
+      diff = max - @max
+      @max = max
+      Thread.critical = FALSE
+      diff.times do
+	t = @queue_wait.shift
+	t.run if t
+      end
+    end
+    max
+  end
+
+  def push(obj)
+    Thread.critical = true
+    while @que.length >= @max
+      @queue_wait.push Thread.current
+      Thread.stop
+      Thread.critical = true
+    end
+    super
+  end
+
+  def pop(*args)
+    Thread.critical = true
+    if @que.length < @max
+      t = @queue_wait.shift
+      t.run if t
+    end
+    super
+  end
+
+  def num_waiting
+    @waiting.size + @queue_wait.size
+  end
 end