On Fri, Jun 3, 2011 at 12:24 PM, Chris <[email protected]> wrote: > Read "Double-Checked Locking; Clever but Broken" > > http://www.javaworld.com/javaworld/jw-02-2001/jw-0209-double.html > > The pattern, while common, was broken prior to Java 5 and was fixed after > but only if mySingleton is declared volatile.
More on this here: http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html The above article is what reminded me that I had forgotten about the volatile keyword in my original WakefulIntentService. See the "Fixing Double-Checked Locking using Volatile" section. The "static helper inner-class" and similar static initialization approaches work well when there's no configuration necessary, and I use those in many places for managing API level-dependent stuff in Android. In my WakefulIntentService case, though, I am initializing a WakeLock, and so I need a Context to get the PowerManager system service. Hence, double-checked locking with volatile is, AFAIK, as good as it gets for that scenario, modulo perhaps using synchronized() per Ms. Hackborn. -- Mark Murphy (a Commons Guy) http://commonsware.com | http://github.com/commonsguy http://commonsware.com/blog | http://twitter.com/commonsguy Android 3.0 Programming Books: http://commonsware.com/books -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
