PERFORCE change 96081 for review

[John Baldwin]

http://perforce.freebsd.org/chv.cgi?CH=96081

Change 96081 by jhb at jhb_slimer on 2006/04/25 18:32:24

	Bring in up/downgrade tests from jhb_lock.

Affected files ...

.. //depot/projects/smpng/sys/modules/crash2/crash2.c#9 integrate

Differences ...

==== //depot/projects/smpng/sys/modules/crash2/crash2.c#9 (text+ko) ====

@@ -97,6 +97,59 @@
 /* Events. */
 
 static void
+foo_grades(void)
+{
+
+	switch (arc4random() % 10) {
+	case 0:
+		rw_wlock(&foo);
+		DELAY(30);
+		rw_wunlock(&foo);
+		break;
+	case 1:
+	case 2:
+		rw_rlock(&foo);
+		DELAY(40);
+		if (!rw_try_upgrade(&foo)) {
+			rw_runlock(&foo);
+			rw_wlock(&foo);
+			DELAY(40);
+		}
+		DELAY(10);
+		rw_wunlock(&foo);
+		break;
+	case 3:
+	case 4:
+	case 5:
+	case 6:
+		rw_wlock(&foo);
+		DELAY(30);
+		rw_downgrade(&foo);
+		DELAY(20);
+		rw_runlock(&foo);
+		break;
+	default:
+		rw_rlock(&foo);
+		DELAY(50);
+		rw_runlock(&foo);
+	}
+}
+
+static void
+foo_grades_lots(void)
+{
+	int i;
+
+	for (i = 0; i < 50000; i++)
+		foo_grades();
+}
+
+CRASH2_EVENT("lots of foo up/downgrades", foo_grades_lots, foo_grades_lots,
+    foo_grades_lots, foo_grades_lots);
+CRASH2_EVENT("foo up/downgrades", foo_grades, foo_grades, foo_grades,
+    foo_grades);
+
+static void
 bar_sleep(void)
 {