the Garbage Collection Page

Richard Jones

Richard Jones's Garbage Collection page - last updated 12 July 2011
Richard Jones

the Contents

the Garbage Collection page is a comprehensive resource for automatic dynamic memory management a.k.a garbage collection. As well as links to my book on garbage collection and my online, searchable memory management bibliography (over 1,900 entries), it includes links to other garbage collection resources such as software and conference proceedings.

I would also welcome any other suggestions for material or links to include on this page.

Richard Jones

the Books

the Bibliography

the FAQ

the Mailing List

the Software

the Rest

  the News

GCspy logo
GGspy is a novel framework and tool for heap visualisation. The visualiser has been refactored to allow plugin views.
*Memory management benchmarks
Links to repositories of Java, C# and C++ benchmarks designed/used for evaluating memory managers.


the Books

There is an abundant but disparate literature on the subject of garbage collection, most of which is confined to research papers. I have tried to pool this experience into an accessible and unified framework, starting with my first book, Garbage Collection: algorithms for automatic dynamic memory management . My new book, The Garbage Collection Handbook: the art of automatic memory management , addresses new challenges to garbage collection made by recent advances in hardware and software. It explores the consequences of these changes for designers and implementers of high performance garbage collectors.
GC Handbook

The Garbage Collection Handbook, 2011

Along with simple and traditional algorithms, the book covers state-of-the-art parallel, incremental, concurrent, and real-time garbage collection. Algorithms and concepts are often described with pseudocode and illustrations.

"The Garbage Collection Handbook is the most up to date, detailed, and exhaustive collation and description of the current state of the art of the Garbage Collection and Automatic Memory Management available today. Each of our GC engineers has a copy on their desk."
Gil Tene, Chief Technical Officer and co-founder of Azul Systems, 2011.

" Anyone developing software built upon a garbage collector would do well to brush up on the theory that underlies this core subject and there is no better way than to read this excellent book!"
Dr Jon Harrop, Flying Frog Consultancy Ltd, 2011

GC book
logoGC book

Garbage Collection, 1996

Garbage Collection: algorithms for automatic dynamic memory management sets out to pool this experience in a single accessible and unified framework.

"The sort of comprehensive engineering manual that is so rare in computing."
Gregory V. Wilson, Dr. Dobb's Journal, September, 1997.

"I like the book because of its high standards of scholarship. I put it alongside Knuth's series."
Mario Wolzko, Distinguished Engineer, Sun Microsystems Laboratories.

The 1999 printing has an improved index. It also incorporates the corrections from the errata. Confusingly, this printing has the same ISBN as the 1996 one (the modifications were insufficient to warrant a new edition) and online booksellers typically cite it as 1996.

the Bibliography

The bibliography currently contains over 1875 references to papers on
  • garbage collection
including some papers on
  • explicit heap management
  • cache performance
  • program analysis
It is available in HTML, compressed BibTeX and compressed PostScript formats.

I would be very grateful for additions, corrections and more URL's for the bibliography. Broken links are a menace: if you move things, please let me know.

The tools that I use to maintain the bibliography are freely available. If you use them please let me know; an acknowledgement would also be nice.

the FAQ

David Chase maintains a GC-faq for Garbage Collection. It contains answers to common questions, folk myths and truths as well as material on garbage collection for C and C++, language interfaces, basic algorithms and more advanced material.

the Mailing List

John Levine looks after a garbage collection mailing list. To subscribe, send
sub gclistor
sub gclist-digest

The mailing list has a home page (mostly empty) containing a FAQ and an archive with messages grouped by month in the usual Unix format mailboxes.

To send mail to the list,


the Software

Open source garbage collectors
The MMTk Memory Manager Toolkit
MMTk is a toolkit for constructing garbage collectors, written in Java. It is used in the Jikes RVM Java virtual machine and other systems.
Apple's Autozone collector
Apple's GC is a mostly-exact conservative, generational, mostly-concurrent open source collector. This page describes an older version (pre Snow Leopard).
Benchmarks for GC, etc

The UK Memory Management Network (coordinated by Richard Jones) maintains a list of benchmarks for Java, C# and C++ programs (see the Resources page). These benchmarks are intended, or have been used, for evaluating memory managers.

Garbage collectors for C and C++ are available from

The Boehm-Weiser Conservative Collector
A mark-sweep collector that can be used with C and C++. There's also a mailing list for questions specific to this collector: subscribe by email to
The following are older implementations, which may or may not still be supported
Yonezawa Laboratory's parallel collector
A parallel extension to the Boehm-Weiser collector.
Debugging tools Below debugging tools for dynamic memory management (amongst other things), mostly commercial.
GGspy is a novel framework and tool for heap visualisation. [report] [screenshots]
Memory Scape from Totalview
leak detection, memory event tracking etc on a wide variety of platforms.
Parallel Inspector XE, part of Intel's Parallel Studio.
Performs heap analysis and other stuff (detects loads of uninitialized data, for instance).
Purify from IBM Rational
Widely used run-time and memory error detection tool for Unix and WindowsNT.
Insure++ from ParaSoft
Compile-time and memory error detection tool for C and C++ running on a variety of platforms.
ElectricFence uses virtual memory hardware to detect when software overruns malloc() buffer boundaries, and/or to detect any accesses of memory released by free().
Profiler and memory debugger for Java (versions for Solaris and Windows 95/98/NT).
Valgrind is an open-source memory debugger for x86-GNU/Linux. When a program is run under Valgrind's supervision, all reads and writes of memory are checked, and calls to malloc/new/free/delete are intercepted.
Memory Analyzer
The SAP Memory Analyzer is a fast and feature-rich heap analyser that helps find big chunks of memory and identify who is keeping these objects alive. It was developed to analyse productive heap dumps with hundreds of millions of objects. Once the heap dump is parsed, you can re-open it, get the retained size of single objects and approximate the retained size of a set of objects.
TuningFork is a system for the visualisation, analysis, and control of real-time systems. It provides both on-line and off-line visualisation of real-time events, with capabilities to play, rewind, zoom and pause the execution. [report]
Other products
NewMonics Inc's Java Virtual Machine for embedded real-time systems.

the Rest

I will also try to maintain a list of links to other GC-related places.
Conference and Workshop Proceedings
  • MetaTF program traces. MetaTF is proposed as a standard for publishing and exchanging representative allocation workloads. The repository contains a definition of MetaTF, tools, traces and trace specifications.
  • The Ravenbrook Memory Management Reference page includes a comprehensive glossary, a FAQ, articles, links and a bibliography as well as news of memory management related events. (Ravenbrook acquired the Reference from Global Graphics, who took over Harlequin, in 2001.)

Tutorials and talks


Garbage : the band
A garbage-collecting wrist watch

GC book logo Richard Jones' home page
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