Java Preferences deadlock

Issue

• We see a deadlock like the following when using a custom Preferences implementation:

"MSC service thread 1-1":
    at java.util.prefs.AbstractPreferences.node(AbstractPreferences.java:827)
    - waiting to lock <0x00000000c90f6b90> (a java.lang.Object)
    at java.util.prefs.AbstractPreferences.node(AbstractPreferences.java:843)
    - locked <0x00000000c8339610> (a java.lang.Object)
    at java.util.prefs.AbstractPreferences.node(AbstractPreferences.java:843)
    - locked <0x00000000c8339640> (a java.lang.Object)
    at java.util.prefs.AbstractPreferences.node(AbstractPreferences.java:843)
    - locked <0x00000000c83548b0> (a java.lang.Object)
    at java.util.prefs.AbstractPreferences.node(AbstractPreferences.java:817)
    at java.util.prefs.Preferences.systemNodeForPackage(Preferences.java:412)
...
"MSC service thread 1-3":
    at java.util.prefs.AbstractPreferences.get(AbstractPreferences.java:281)
    - waiting to lock <0x00000000c8339610> (a java.lang.Object)
    at com.source.CustomPreferences.getSpi(CustomPreferences.java:100)
    at java.util.prefs.AbstractPreferences.get(AbstractPreferences.java:287)
    - locked <0x00000000c90f6b90> (a java.lang.Object)