garbage collection - Java heap terminology: young, old and permanent generations? -

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I am trying to understand that the young , the old and Java Hip terminology in lasting generations , and more specifically the interaction between three generations.

My questions are:

  • What is the younger generation?
  • What is the old generation?
  • What is a permanent generation?
  • How do three generations interact with each other?

It seems like a general misconception in Oracle's JVM, part of a permanent generation pile is not. It is a separate place for classroom definitions and related data, in Java 6 and earlier versions, the interning string was also stored in a permanent generation. In Java 7, the interning strings are stored in the main object heap.

This is one.

I like the details given for each location of the oracle:

For the hotspot Java VM, the memory pool for serial waste collection is as follows.

  • Eden Space: The pool that initially has allocated memory for most objects.
  • Survivor Space (Pile): Objects with pool that have escaped the Eden Space trash collection.
  • TenorAir Generation (heap): Survivorous space with objects with pool which are present for some time.
  • Permanent generation (non-stack): The pool in which the virtual machine has all the reflected data, such as class and method objects. Java VM, which use class data sharing, this generation is divided into read-only and read-write areas.
  • Code cache (non-stack): Hotspot Java VM includes a code cache, which contains memory, is used to compile and archive the original code. Java uses the generational waste collection, which means that if you have an object FU (which is an example of some class), then it is more garbage collection incidents. If left (if there is still reference about it), then it will be pushed forward. This young generation (which itself is divided in many places - starts in Eden and Survivor) and eventually ends in the ending generation, if it survives for a long time.


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