Where Storage Lives

tags

Programming Language Concept

source

DT-On Java 8

Registers

• fastest: inside CPU
• limited Numbers
• typically no direct control over register allocation

Stack

• lives in genral random-access memory (RAM)
• direct support from the processor via stack pointer
• fast and efficient way to allocate storage

Heap

• pool of memory, also lives in RAM
• technically slower than stack when allocating and releasing memory
  • overheads
    • find unused chunks with required space
    • bookkeeping mappings of chunks and addresses passed to caller

Constant storage

• placed directly in the program code -> safe
• in some special cases, some constants can be placed in other special locations
  • string literals in Java

Non-RAM storage

Turn objects into something exist on the other medium, and yet be resurrected into a regular RAM-based object when necessary.

• serialized objects #serialization turn objects intio streams of bytes, usually used when sending objects to another machine

• persistent objects place objects on disk