On 5/16/11 7:00 PM, David Holmes wrote:
Dan,
I'm sorry this didn't come through in time ...
Mandy Chung said the following on 05/17/11 05:22:
Logger.java
Looks good. The removal of the synchronization required by
Logger.getLogger fixes the deadlock issue.
But this method now has a race condition:
372 // Synchronization is not required here. All synchronization for
373 // adding a new Logger object is handled by
LogManager.addLogger().
374 public static Logger getLogger(String name, String
resourceBundleName) {
375 LogManager manager = LogManager.getLogManager();
376 Logger result = manager.demandLogger(name);
377 if (result.resourceBundleName == null) {
378 // Note: we may get a MissingResourceException here.
379 result.setupResourceInfo(resourceBundleName);
380 } else if
(!result.resourceBundleName.equals(resourceBundleName)) {
381 throw new
IllegalArgumentException(result.resourceBundleName +
382 " != " + resourceBundleName);
383 }
384 return result;
385 }
Two threads calling this method with the same name but different
resource bundle names can both see null at line 377 and install their
different resource bundles. That section needs to be atomic.
My bad - missed this race condition.
The setupResourceInfo method synchronizes on this Logger instance. The
resourceBundleName should only be set up to once or same resource bundle
name. I think it should check if this.resourceBundleName is null or
same as the given resourceBundleName; if not, throw IAE. The
if-then-else in L377-383 above is no longer needed and can simply call
result.setupResourceInfo(resourceBundleName).
Mandy
