From f2caa2d1ef10a79f755a511be3bcfcfed992a21b Mon Sep 17 00:00:00 2001
From: knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 11 Sep 2002 07:29:56 +0000
Subject: [PATCH] * lib/thread.rb: Merge from 1.7: Get rid of race condition in
   Queue#pop().

* lib/thread.rb: Merge from 1.7: SizedQueue: new(max) should not
  accept a value <= 0.

* lib/thread.rb: Merge from 1.7: SizedQueue: Properly override
  enq(), shift() and deq().


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_6@2846 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog     | 11 +++++++++++
 lib/thread.rb | 26 +++++++++++---------------
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0029915552..f2549a182a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+Wed Sep 11 16:24:22 2002  Akinori MUSHA  <knu@iDaemons.org>
+
+	* lib/thread.rb: Merge from 1.7: Get rid of race condition in
+	  Queue#pop().
+
+	* lib/thread.rb: Merge from 1.7: SizedQueue: new(max) should not
+	  accept a value <= 0.
+
+	* lib/thread.rb: Merge from 1.7: SizedQueue: Properly override
+	  enq(), shift() and deq().
+
 Wed Sep 11 16:15:06 2002  Akinori MUSHA  <knu@iDaemons.org>
 
 	* lib/tempfile.rb: Merge from 1.7: Add Tempfile#size.
diff --git a/lib/thread.rb b/lib/thread.rb
index 34db9c3d46..1a08aa7761 100644
--- a/lib/thread.rb
+++ b/lib/thread.rb
@@ -173,22 +173,14 @@ class Queue
   alias enq push
 
   def pop(non_block=false)
-    Thread.critical = true
-    begin
-      loop do
-       if @que.empty?
-	  if non_block
-	    raise ThreadError, "queue empty"
-	  end
-	  @waiting.push Thread.current
-	  Thread.stop
-	else
-	  return @que.shift
-	end
-      end
-    ensure
-      Thread.critical = false
+    while (Thread.critical = true; @que.empty?)
+      raise ThreadError, "queue empty" if non_block
+      @waiting.push Thread.current
+      Thread.stop
     end
+    @que.shift
+  ensure
+    Thread.critical = false
   end
   alias shift pop
   alias deq pop
@@ -215,6 +207,7 @@ end
 
 class SizedQueue<Queue
   def initialize(max)
+    raise ArgumentError, "queue size must be positive" unless max > 0
     @max = max
     @queue_wait = []
     @queue_wait.taint		# enable tainted comunication
@@ -256,6 +249,7 @@ class SizedQueue<Queue
     super
   end
   alias << push
+  alias enq push
 
   def pop(*args)
     retval = super
@@ -276,6 +270,8 @@ class SizedQueue<Queue
     end
     retval
   end
+  alias shift pop
+  alias deq pop
 
   def num_waiting
     @waiting.size + @queue_wait.size