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ALPINiSM

ALPINiSM (Abstraction Layer for Programming Persistent Shared Memory) provides a low-level abstraction layer that reliefs the user from the details of mapping, addressing, and allocating persistent shared memory (also known as fabric-attached memory). This layer can be used as a building block for building higher level abstractions and data structures such as heaps, logs, etc.

Building ALPINiSM

$ cd $ALPS
$ mkdir build
$ cd build

For Debug build type (default):

$ cmake .. -DTARGET_ARCH_MEM=NV-NCC-FAM -DCMAKE_BUILD_TYPE=Debug

For Release build type:

$ cmake .. -DTARGET_ARCH_MEM=NV-NCC-FAM -DCMAKE_BUILD_TYPE=Release

Installing Dependencies

L4TM

apt-get install vim git apt-get install cmake apt-get install libnuma apt-get install libnuma-dev

apt-get install libconfig++-dev

sudo apt-get install libboost-all-dev

OR

sudo apt-get install libboost-dev sudo apt-get install libboost-serialization-dev

sudo apt-get install libattr1-dev sudo apt-get install libyaml-cpp-dev

sudo apt-get install python3

RedHat

sudo yum install attr1

Example Programs

ALPINiSM comes with several samples in the examples directory.

Running Tests

Style Guide

We follow the Google C++ style guide available here:

https://google.github.io/styleguide/cppguide.html

Frequently Asked Questions

Why yet another persistent memory allocator?

Several persistent memory allocators already exist. For example, libpmemobj is an industrial-strength library developed by Intel that provides a transactional object store, including a persistent memory allocator. Although, it was likely developed before our allocator, to the best of our knowledge, the first stable implementation and public description appeared later in mid-June 2015 (http://pmem.io/2015/06/11/type-safety-macros.html), about the time when we started work on our own memory allocator.

We considered leveraging libpmemobj for building our allocator given its maturity but we eventually decided in favor of building our own. In general, libpmemobj makes different design assumptions about the underlying hardware that would make such a porting exercise a challenging task. In particular:

• libpmemobj has no support for multiple process. Extending it to multiple processes would require introducing inter-process synchronization, extend the code to deal with in-coherent accesses to allocator metadata between multiple processes, and reorganize the heap layout (e.g. shard the heap) to reduce expensive fabric synchronization between multiple processes.
• libpmemobj's allocator appears to be coupled with the transactional object store.
• libpmemobj's type-safe pointer addressing scheme is implemented in C. This is a heroic attempt to introduce type-safety to a language that is not type safe, and not surprisingly the end result suffers from a lot of ugliness. Instead, we choose to implement smart pointers in C++ and benefit from C++ type system.
• libpmemobj supports only mirroring and provides no flexibility in replication.
• We would have less flexibility and control over the design and implementation of the allocator.