Add comments about possible lock contention

Bug: 149308087
Test: TreeHugger
Change-Id: I06f03e48945d725d4722c297dba200361fd9dce2
diff --git a/test/1932-monitor-events-misc/src/art/Test1932.java b/test/1932-monitor-events-misc/src/art/Test1932.java
index 7f66884..aee811a 100644
--- a/test/1932-monitor-events-misc/src/art/Test1932.java
+++ b/test/1932-monitor-events-misc/src/art/Test1932.java
@@ -222,6 +222,7 @@
     controller2.DoLock();
     controller2.waitForLockToBeHeld();
     controller2.DoNotifyAll();
+    // See comment in testWaitMonitorEnter.
     controller2.DoUnlock();
     controller1.waitForLockToBeHeld();
     controller1.DoUnlock();
@@ -249,6 +250,10 @@
     controller2.DoLock();
     controller2.waitForLockToBeHeld();
     controller2.DoNotifyAll();
+    // We've seen extra messages about contended locking here. They're OK if e.g. controller1
+    // wakes up spuriously before the notification, which is allowed. But in the normal case,
+    // we should not see contended locking here. And the extra messages seem rare enough that
+    // we can tolerate the spurious failures to catch more bugs. See b/149308087.
     controller2.DoUnlock();
     controller1.waitForLockToBeHeld();
     controller1.DoUnlock();
@@ -275,6 +280,7 @@
     controller1.DoLock();
     controller1.waitForLockToBeHeld();
     controller1.DoNotifyAll();
+    // See comment in testWaitMonitorEnter.
     controller2.waitForLockToBeHeld();
     controller2.DoUnlock();
   }
@@ -307,6 +313,7 @@
     controller1.DoLock();
     controller1.waitForLockToBeHeld();
     controller1.DoNotifyAll();
+    // See comment in testWaitMonitorEnter.
     controller1.DoUnlock();
     // Wait for controller3 to have locked.
     // We cannot use waitForLockToBeHeld since we could race with the HANDLER waitForLockToBeHeld
@@ -349,6 +356,7 @@
     controller1.DoLock();
     controller1.waitForLockToBeHeld();
     controller1.DoNotifyAll();
+    // See comment in testWaitMonitorEnter.
     controller1.DoUnlock();
     controller2.waitForLockToBeHeld();
     controller2.DoUnlock();
@@ -418,6 +426,7 @@
     controller2.DoLock();
     controller2.waitForLockToBeHeld();
     controller2.DoNotifyAll();
+    // See comment in testWaitMonitorEnter.
     controller2.DoUnlock();
     try {
       controller1.waitForLockToBeHeld();