flloc: A dynamic memory debugger

Introduction

Flloc is a simple dynamic memory checker whose job is to check for memory leaks (in addition, it checks for memory corruptions around allocated memory blocks). Flloc works with multi-threaded executables.

Flloc is dual-licensed under the GPLv3 and a commercial license. If you require the commercial license, please contact me: "Fabrice Triboix" .

This project has been created because I couldn't find a simple, thread-aware memory debugger that would minimise its impact on the running of the software.

Getting started

Follow the steps:

$ $EDITOR Makefile  # Edit to suit your environment
$ make test         # Compile & run unit tests
$ make install      # Install

How to use flloc

In your source files, include flloc.h. Add -lflloc to the list of libraries you link against. Then run your executable. Flloc will print memory corruptions in the guard buffers (see below), and any detected memory leak when the executable exits.

You can tune flloc behaviour by setting the FLLOC_CONFIG environment variable prior to running your executable thus:

$ export FLLOC_CONFIG="FILE=/path/to/flloc.log;GUARD=10000"

Where FILE is the path to a file where flloc will write its output (default is to print to stderr), and GUARD is the size of the guard buffers (in bytes). Guard buffers are padding before and after each dynamically allocated block of memory; they are used to detect corruptions, where the code writes into memory outside what has been allocated. You can set it to 0 to disable this feature (default is 1024).

Flloc uses macros to redefine malloc() & co. There are multiple reasons for doing this instead of using hooks or overriding weak malloc() & co symbols:

To keep it simple
To check flloc itself for memory leaks
To ignore memory leaks occuring outside your code, or even to pinpoint accurately which part of your code should be checked

No warranties

I wrote these pieces of code on my spare time in the hope that they will be useful. I make no warranty at all on their suitability for use in any type of software application.

Copyright

This software is dual-license under the GPLv3 and a commercial license. The text of the GPLv3 is available in the LICENSE file.

A commercial license can be provided if you do not wish to be bound by the terms of the GPLv3, or for other reasons. Please contact me for more details.