97     static Preferences userRoot = null;

    97     private static volatile Preferences userRoot;

    98 

    98 

    99     static synchronized Preferences getUserRoot() {

    99     static Preferences getUserRoot() {

   100         if (userRoot == null) {

   100         Preferences root = userRoot;

   101             setupUserRoot();

   101         if (root == null) {

   102             userRoot = new FileSystemPreferences(true);

   102             synchronized (FileSystemPreferences.class) {

   103         }

   103                 root = userRoot;

   104         return userRoot;

   104                 if (root == null) {

   105                     setupUserRoot();

   106                     userRoot = root = new FileSystemPreferences(true);

   107                 }

   108             }

   109         }

   110         return root;

   158     static Preferences systemRoot;

   164     private static volatile Preferences systemRoot;

   159 

   165 

   160     static synchronized Preferences getSystemRoot() {

   166     static Preferences getSystemRoot() {

   161         if (systemRoot == null) {

   167         Preferences root = systemRoot;

   162             setupSystemRoot();

   168         if (root == null) {

   163             systemRoot = new FileSystemPreferences(false);

   169             synchronized (FileSystemPreferences.class) {

   164         }

   170                 root = systemRoot;

   165         return systemRoot;

   171                 if (root == null) {

   172                     setupSystemRoot();

   173                     systemRoot = root = new FileSystemPreferences(false);

   174                 }

   175             }

   176         }

   177         return root;