--- jsr166/src/test/tck/PhaserTest.java	2011/06/22 07:46:57	1.33
+++ jsr166/src/test/tck/PhaserTest.java	2011/11/18 20:11:17	1.36
@@ -165,8 +165,8 @@ public class PhaserTest extends JSR166Te
     }
 
     /**
-     * register() correctly returns the current barrier phase number when
-     * invoked
+     * register() correctly returns the current barrier phase number
+     * when invoked
      */
     public void testRegister3() {
         Phaser phaser = new Phaser();
@@ -177,8 +177,8 @@ public class PhaserTest extends JSR166Te
     }
 
     /**
-     * register causes the next arrive to not increment the phase rather retain
-     * the phase number
+     * register causes the next arrive to not increment the phase
+     * rather retain the phase number
      */
     public void testRegister4() {
         Phaser phaser = new Phaser(1);
@@ -189,6 +189,33 @@ public class PhaserTest extends JSR166Te
     }
 
     /**
+     * register on a subphaser that is currently empty succeeds, even
+     * in the presence of another non-empty subphaser
+     */
+    public void testRegisterEmptySubPhaser() {
+        Phaser root = new Phaser();
+        Phaser child1 = new Phaser(root, 1);
+        Phaser child2 = new Phaser(root, 0);
+        assertEquals(0, child2.register());
+        assertState(root, 0, 2, 2);
+        assertState(child1, 0, 1, 1);
+        assertState(child2, 0, 1, 1);
+        assertEquals(0, child2.arriveAndDeregister());
+        assertState(root, 0, 1, 1);
+        assertState(child1, 0, 1, 1);
+        assertState(child2, 0, 0, 0);
+        assertEquals(0, child2.register());
+        assertEquals(0, child2.arriveAndDeregister());
+        assertState(root, 0, 1, 1);
+        assertState(child1, 0, 1, 1);
+        assertState(child2, 0, 0, 0);
+        assertEquals(0, child1.arriveAndDeregister());
+        assertTerminated(root, 1);
+        assertTerminated(child1, 1);
+        assertTerminated(child2, 1);
+    }
+
+    /**
      * Invoking bulkRegister with a negative parameter throws an
      * IllegalArgumentException
      */
@@ -200,8 +227,8 @@ public class PhaserTest extends JSR166Te
     }
 
     /**
-     * bulkRegister should correctly record the number of unarrived parties with
-     * the number of parties being registered
+     * bulkRegister should correctly record the number of unarrived
+     * parties with the number of parties being registered
      */
     public void testBulkRegister2() {
         Phaser phaser = new Phaser();