--- old/src/share/classes/sun/management/Agent.java	2012-04-11 14:48:00.217790277 +0800
+++ new/src/share/classes/sun/management/Agent.java	2012-04-11 14:48:00.045789432 +0800
@@ -264,8 +264,12 @@
 
         // management properties can be overridden by system properties
         // which take precedence
-        props.putAll(System.getProperties());
-
+        // putAll will fail if system properties are modified
+        // while copying them, so we need synchronize the system properties
+        Properties sysProps = System.getProperties();
+        synchronized (sysProps) {
+            props.putAll(sysProps);
+        }
         return props;
    }