src/share/classes/sun/nio/cs/AbstractCharsetProvider.java

*** 177,188 ****
--- 177,190 ----
                      return i.hasNext();
                  }
  
                  public Charset next() {
                      String csn = i.next();
+                     synchronized (AbstractCharsetProvider.this) {
                          return lookup(csn);
                      }
+                 }
  
                  public void remove() {
                      throw new UnsupportedOperationException();
                  }
              };