* lib/sync.rb (Sync_m#sync_lock): Fixed wakeup/raise unsafe code.

Patched by Masaki Matsushita. [Bug #5355] [ruby-dev:44521]

* test/thread/test_sync.rb (test_sync_lock_and_wakeup,
  test_sync_upgrade_and_wakeup, test_sync_lock_and_raise):
  new test.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36936 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,12 @@
+Sun Sep  9 20:20:31 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* lib/sync.rb (Sync_m#sync_lock): Fixed wakeup/raise unsafe code.
+	  Patched by Masaki Matsushita. [Bug #5355] [ruby-dev:44521]
+
+	* test/thread/test_sync.rb (test_sync_lock_and_wakeup,
+	  test_sync_upgrade_and_wakeup, test_sync_lock_and_raise):
+	  new test.
+
 Sun Sep  9 18:39:46 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* include/ruby/intern.h (rb_thread_blocking_region): Added

lib/sync.rb

@@ -138,16 +138,22 @@ module Sync_m
 
     while true
       @sync_mutex.synchronize do
-        if sync_try_lock_sub(m)
-          return self
-        else
-          if sync_sh_locker[Thread.current]
-            sync_upgrade_waiting.push [Thread.current, sync_sh_locker[Thread.current]]
-            sync_sh_locker.delete(Thread.current)
+        begin
+          if sync_try_lock_sub(m)
+            return self
           else
-            sync_waiting.push Thread.current
+            if sync_sh_locker[Thread.current]
+              sync_upgrade_waiting.push [Thread.current, sync_sh_locker[Thread.current]]
+              sync_sh_locker.delete(Thread.current)
+            else
+              unless sync_waiting.include?(Thread.current) || sync_upgrade_waiting.reverse_each.any?{|w| w.first == Thread.current }
+                sync_waiting.push Thread.current
+              end
+            end
+            @sync_mutex.sleep
           end
-          @sync_mutex.sleep
+        ensure
+          sync_waiting.delete(Thread.current)
         end
       end
     end

test/thread/test_sync.rb

@@ -0,0 +1,57 @@
+require 'test/unit'
+require 'sync'
+require 'timeout'
+
+class SyncTest < Test::Unit::TestCase
+  class Tester
+    include Sync_m
+  end
+
+  def test_sync_lock_and_wakeup
+    tester = Tester.new
+
+    tester.sync_lock(:EX)
+
+    t = Thread.new { tester.sync_lock(:EX) }
+
+    sleep 0.1 until t.stop?
+    t.wakeup
+    sleep 0.1 until t.stop?
+
+    assert_equal(tester.sync_waiting.uniq, tester.sync_waiting)
+  end
+
+  def test_sync_upgrade_and_wakeup
+    tester = Tester.new
+    tester.sync_lock(:SH)
+
+    t = Thread.new do
+      tester.sync_lock(:SH)
+      tester.sync_lock(:EX)
+    end
+
+    sleep 0.1 until t.stop?
+    t.wakeup
+    sleep 0.1 until t.stop?
+
+    tester.sync_upgrade_waiting.each { |ary|
+      assert(!tester.sync_waiting.include?(ary[0]))
+    }
+    assert_equal(tester.sync_waiting.uniq, tester.sync_waiting)
+    assert_equal(tester.sync_waiting, [])
+  end
+
+  def test_sync_lock_and_raise
+    tester= Tester.new
+    tester.sync_lock(:EX)
+
+    t = Thread.new { tester.sync_lock(:EX) }
+
+    sleep 0.1 until t.stop?
+    t.raise
+    sleep 0.1 while t.alive?
+
+    assert_equal(tester.sync_waiting.uniq, tester.sync_waiting)
+    assert_equal(tester.sync_waiting, [])
+  end
+end