Download Enhanced Heap Visualization with GCspy

The GCspy framework
3
Chapter 2
The GCspy framework
2.1 Overview
GCspy is an architectural framework for collection, transmission, storage and visualization of heap information. It is not specific to any particular application or runtime
environment and can easily be adapted for use with any memory management system.
[Printezis02]
This chapter analyzes the architecture of GCspy and how the individual components
communicate with it each other. It then goes on to illustrate how the layout of heaps
is abstracted using general, non-specific data structures in GCspy. Finally, GCspy is
compared to other tools for visualizing runtime heap information.
2.2 GCspy architecture
GCspy is designed and implemented as a client-server architecture.
The server component runs within the observed application or its virtual machine. The
GCspy client connects to the server via a TCP/IP socket connection. Triggered by
certain events such as a garbage collector run, the server sends a snapshot of the heap to
the client. The client then interprets and visualizes the received data. It also maintains
an index with a history of received snapshots to allow viewing the state of the heap at
previous points in time.
The GCspy framework provides the server infrastructure as libraries for C, C++ and
Java. The client (also called visualizer) is a Java application with a Swing user interface.
Developers only need to implement data collection in their memory management system
and provide a driver that interprets and preprocesses the collected data for use with
GCspy. Due to the representation of the heap layout in abstract structures, the client
does not require any modifications for supporting new memory management systems.