计算机专业外文翻译(Java垃圾收集器)

本科生毕业设计（论文） 第 1 页

How a garbage collector works of Java Language

If you come from a programming language where allocating objects on the heap is

expensive, you may naturally assume that Java’s scheme of allocating everything

(except primitives) on the heap is also expensive. However, it turns out that the

garbage collector can have a significant impact on increasing the speed of object

creation. This might sound a bit odd at first—that storage release affects storage

allocation—but it’s the way some JVMs work, and it means that allocating storage for

that object storage allocation is remarkably rapid. The “heap pointer” is simply moved

forward into virgin territory, so it’s effectively the same as C++’s stack allocation. (Of

course, there’s a little extra overhead for bookkeeping, but it’s nothing like searching

for storage.)

You might observe that the heap isn’t in fact a conveyor belt, and if you treat it that

way, you’ll start paging memory—moving it on and off disk, so that you can appear to

have more memory than you actually do. Paging significantly impacts performance.

Eventually, after you create enough objects, you’ll run out of memory. The trick is

that the garbage collector steps in, and while it collects the garbage it compacts all the

objects in the heap so that you’ve effectively moved the “heap pointer” closer to the