Users using the jvmstat API might register a VmListener in order to get notified on monitor updates (fireMonitorsUpdatedEvents() in LocalMonitoredVm.java).

Internally a Timer is used to notify listeners on a given interval. However, when a NotifierTask throws an unchecked exception, the Timer dies, preventing any further updates for any monitors.

One such instance where a runtime exception might occur in NotifierTask is when a JVM is currently active waiting for a debugger to attach.

This could be a potential fix:
diff --git a/src/share/classes/sun/jvmstat/perfdata/monitor/protocol/local/LocalMonitoredVm.java b/src/share/classes/sun/jvmstat/perfdata/monitor/protocol/local/LocalMonitoredVm.java
--- a/src/share/classes/sun/jvmstat/perfdata/monitor/protocol/local/LocalMonitoredVm.java
+++ b/src/share/classes/sun/jvmstat/perfdata/monitor/protocol/local/LocalMonitoredVm.java
@@ -202,6 +202,11 @@
                 System.err.println("Exception updating monitors for "
                                    + getVmIdentifier());
                 e.printStackTrace();
+ } catch (Throwable e) {
+ // XXX: use logging api
+ System.err.println("Exception updating monitors for "
+ + getVmIdentifier());
+ e.printStackTrace();
             }
         }
     }