EVALUATION

http://hg.openjdk.java.net/jdk7/build/jdk/rev/01b6d147db50
                                     

SUGGESTED FIX

Of course, my previous comment is completely wrong,
because initialization of "bugLevel" has to be delayed until after
System property infrastructure has been set up.

I agree with the suggested fix.... except that....

I think we can get away without a "volatile" on this variable.
This is skating on thin ice, but appears to be safe here because:
- redundant initialization of "bugLevel" is harmless
- String is one of the very few classes that is race-safe.  That is,
  if multiple threads access a String, even in the presence of a data race,
  they are guaranteed to see the same value.
                                     

SUGGESTED FIX

I suggest using 

private static final String bugLevel = ...

to ensure static initialization.  There is no point to lazy initialization;
it seems that atBugLevel will certainly be called in every Java program.

Martin
                                     

SUGGESTED FIX

------- Charset.java -------
*** /tmp/sccs.FhaqDt	Thu Feb 22 17:51:08 2007
--- Charset.java	Thu Feb 22 17:40:52 2007
***************
*** 243,249 ****
  
      /* -- Static methods -- */
  
!     private static String bugLevel = null;
  
      static boolean atBugLevel(String bl) {		// package-private
  	if (bugLevel == null) {
--- 243,249 ----
  
      /* -- Static methods -- */
  
!     private static volatile String bugLevel = null;
  
      static boolean atBugLevel(String bl) {		// package-private
  	if (bugLevel == null) {
***************
*** 251,261 ****
  		return false;
  	    java.security.PrivilegedAction pa =
  		new GetPropertyAction("sun.nio.cs.bugLevel");
! 	    bugLevel = (String)AccessController.doPrivileged(pa);
! 	    if (bugLevel == null)
! 		bugLevel = "";
  	}
! 	return (bugLevel != null) && bugLevel.equals(bl);
      }
  
      /**
--- 251,260 ----
  		return false;
  	    java.security.PrivilegedAction pa =
  		new GetPropertyAction("sun.nio.cs.bugLevel");
! 	    String value = (String)AccessController.doPrivileged(pa);
! 	    bugLevel = (value != null) ? value : "";
  	}
! 	return bugLevel.equals(bl);
      }
  
      /**
                                     

EVALUATION

Race condition and a data race in Charset's atBugLevel method.