MemoryManager plugin for Eclipse

MemoryManager plugin for Eclipse

这个插件不错，可以监视JVM的内存使用情况，并且可以强制GC工作。


Current Version 1.0.0. Released Feb 1st 2004

Description

Cloudgarden's MemoryManager is a small plugin for IBM's Eclipse Java I DE, which displays the current memory usage of Eclipse (letting you know when Eclipse is close to using up all it's memory allowance), and automatically invokes garbage collection when deemed necessary by a simple but effective algorithm (see below), thus preventing or reducing times of forced inactivity while the Eclipse JVM cleans up it's virtual memory space.

The plugin takes up little screen real estate, and provides a visual and numerical display of the free, total and maximum memory allocations, as well as indicating when it forced a garbage collection (it also has a button to manually force garbage collection). In the screen shot, the green region represents the free memory, the red region the used memory (which is equal to the total memory minus the free memory) and the black region represents space for expansion. The blue lines indicate when a garbage-collection happened. Scrolling of the display can be paused and re-started, and past values can be stepped through as a simple tool for analysing memory usage by applications in the workbench.

The plugin is Open Source, (the source is here) and should work on most platforms (it has been tested on Windows, Linux and Mac).


Download

The plugin is contained in this file. Simply extract and install in your eclipse folder, then start eclipse.


Usage

Show the plugin by choosing "Windows->Views->Other->MemoryManager->Memory" in the eclipse main menu. The plugin will immediately start displaying memory usage and collecting garbage when necessary. Note: If total usage is less than half of the maximum allowed space, the display will be scaled vertically by a factor of two (ie, the height of the display represents only half of the maximum memory), but once the total memory excedes half of the maximum, the height represents the maximum allowed memory usage.


Requirements

Eclipse version 2.1.2 or 3M6. If run under a 1.3 JVM, the maximum memory cannot be calculated (since there is no such method in the 1.3 API), and the display will have no black area.


Garbage collection algorithm

1) At startup, or immediately after garbage-collection, find the free memory.
2) Keep checking free memory every second or two.
3) When the free memory drops below 75% of the free memory after the last garbage collection (or at startup), do another garbage-collection.

That's it - simple, but apparently effective.