This week's book giveaway is in the OCAJP forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide 1Z0-808 and have Jeanne Boyarsky & Scott Selikoff on-line! See this thread for details.
Hi Thank you for reading my post. 1-Are static methods thread safe ? I mean if i declare a method to be static , will it run in guarded mode ? 2-if static methods are thread safe , does JVM run them internally in Synchronized mode?
Static-ness and thread safety are unrelated concepts. The JVM runs them in synchronized mode only if they're declared to be synchronized, or part of a synchronized block. So a static method needs to take the same precautions a non-static method would take against concurrent access problems.
In general what makes something unsafe is two threads locking or modifying a shared resource like an object, file, database or partner system. Your method didn't do that, so it's ok for now.
You could have a shared resource as a static varible, a parameter, a member variable on a singleton, anything you get from another method, anything you give to another method or something external to your code. I bet there are more ways I didn't think of just now. All this can make maintaining thread safety kind of tricky!
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi