This is a debug heap useful when trying to track down memory errors (especially on Windows, where there's no Valgrind.) It is written in C, and works on Mac, Linux and Windows.

This package provides the following features:

• Array indexing errors (positive) trigger crashes, because allocations are aligned as closely as possible up to an inaccessible virtual memory page.

• Using memory after freeing it triggers a crash most of the time.

• Double frees are detected most of the time.

• Unsynchronized multi-threaded access is detected.

To improve the chances of crashing on use-after-free or double frees, increase the size of the heap. Freed blocks are kept on an "observation list" for as long as possible to flush out these error classes, but it will eventually be reused.

This heap is terribly slow, and wastes tons of memory. You only want to use it to track down memory errors. One neat way of doing that is to provide a heap interface that can dynamically switch to this heap, maybe with a configuration option. You can then hunt for memory errors without recompiling.

Copyright (c) 2014, Insomniac Games All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.