JVM may get upgrade to support today’s multicore processors

Posted on 20-06-2017 , by: admin , in , 0 Comments

Oracle is proposing an update to the Java Virtual Machine to allow for direct-value class types, a modernization required by the advent of multicore processors. There is no schedule for when the changes might appear in the JVM.

The changes to the JVM specification would support a prototype of value classes—classes for which primitive-like non-reference value instances can be created and acted upon. “The proposals for value types in Java are about giving developers the alternative to give up identity and polymorphism so that the runtime can represent the underlying data in a way which is both far more compact and much better suited for processing in bulk operations,” said Georges Saab, Oracle’s vice president of software development in the Java platform group.

In explaining the plan, Saab said when Java was created in 1995, memory access and CPU instructions took about the same amount of time. Since then, the introduction of multicore processors has increased the speed of CPU instructions but made memory locality a challenge. 

For Java primitives, this time mismatch is not an issue. But it is an issue for objects, because of inherent assumptions about identity and polymorphism, Saab said.