memtailor

Memtailor is a C++ library of special purpose memory allocators. It currently offers an arena allocator and a memory pool.

The main motivation to use a memtailor allocator is better and more predictable performance than you get with new/delete. Sometimes a memtailor allocator can also be more convenient due to the ability to free many allocations at one time.

The Memtailor memory pool is useful if you need to do many allocations of a fixed size. For example a memory pool is well suited to allocate the nodes in a linked list.

You can think of the Memtailor arena allocator as being similar to stack allocation. Both kinds of allocation are very fast and require you to allocate/deallocate memory in last-in-first-out order. Arena allocation has the further benefits that it stays within the C++ standard, it will not cause a stack overflow, you can have multiple arena allocators at the same time and allocation is not tied to a function invocation.

Requirements

Memtailor requires C++17 or later.

Building and using with CMake

cmake -S . -B build-dir -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=ON
cmake --build build-dir
ctest --test-dir build-dir --output-on-failure
cmake --install build-dir --prefix /your/install/prefix

Use -DBUILD_TESTING=OFF to omit unit tests and their GoogleTest dependency. Install directories follow GNUInstallDirs; for example, -DCMAKE_INSTALL_LIBDIR=lib64 selects a 64-bit library directory. The default library type remains static; BUILD_SHARED_LIBS=ON selects shared.

Consumers can use the installed package:

find_package(memtailor 1.4 CONFIG REQUIRED)
target_link_libraries(my_program PRIVATE memtailor::memtailor)

Set CMAKE_PREFIX_PATH to the installation prefix if it is outside the normal system search paths. The exported target carries include directories, C++17, the Threads dependency, and the ABI-affecting MEMT_DEBUG definition when applicable. The installation also provides memtailor.pc for pkg-config users; configure CMAKE_INSTALL_PREFIX to the final prefix when using that file.

Debugging

Defining MEMT_DEBUG turns on memtailor's internal consistency checks. Pass --enable-debug to configure, or build with cmake and -DCMAKE_BUILD_TYPE=Debug.

Be aware that MEMT_DEBUG adds a member to memt::Arena, so it changes the size of that class and hence the ABI of the library. It must match between the library and every translation unit that includes these headers. Mixing the two compiles and links without complaint, but the two sides then disagree about the layout of memt::Arena and the result is undefined behavior.

Both builds record the debug setting in the Cflags of memtailor.pc. Use those Cflags in full: pkg-config --cflags-only-I drops the definition, as does any build system that keeps just the include directories. CMake consumers linking memtailor::memtailor inherit the setting automatically, even when the consumer and library use different build configurations.

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The following copyright and license notice applies to all of the files in memtailor.

Copyright 2013 Bjarke Hammersholt Roune (http://www.broune.com) and Cornell University. MemTailor is distributed under the Modified BSD License. See license.txt.