.. _gsoc-ideas:

Project List
============


This is the project list for Google Summer of Code with Chapel. The list
is constantly growing and evolving, but it should remain relatively static
during the Google Summer of Code application phase.

.. note::
    If you are interested in applying for Chapel's Google Summer of Code 2017,
    please visit the application instructions page:

    - :ref:`gsoc-apply`


.. Suggested Format:
    .. topic:: <Project Title>

        :Description:
            <description>

        :Expected results:
            <what we expect as final product of 12 weeks>

        :Required knowledge:
            <language(s) and technology(s)>

            * C/C++

        :Optional knowledge:
            <language(s) and technology(s)>

            * Chapel
            * Familiarity with parallelism

        :Mentor(s):
            <Team member(s) ideal for mentoring this project>

            Brad Chamberlain

Student Submitted Projects
--------------------------
The project ideas in this list have been compiled by Chapel developers.
Students may submit proposals based on existing ideas here or new ideas
altogether.

.. _ideas-demos:

Libraries and Applications
--------------------------

.. topic:: Your favorite application or library in Chapel

    :Description:
        Build any application in Chapel that might show off its productivity,
        performance, and/or elegance. This could be anything from a port of an
        email client library to a standalone molecular dynamics engine. The
        world is your oyster, and we're excited to mentor you along the way to
        building your application in Chapel.

    :Expected results:
        Expectations will be tuned specifically to the project. In a general
        sense, the application or library should reach a state that is ready for
        public use.

    :Optional knowledge:

        * Chapel

    :Mentor(s):
         Andrea Francesco Iuorio, Ben Albrecht, Engin Kayraklioglu, Michael Ferguson


.. topic:: HDF5 Library

    :Description:
       HDF5 (note: not HDFS) is a common data interchange format for scientific
       applications.  Since Chapel is intended to work well for scientific
       programming, having HDF5 support is important.

    :Expected results:

        * a new HDF5 Chapel module that enables high-level access to HDF5 files
        * a Chapel application that demonstrates the use of the new module by
          reading some existing and freely available HDF5 files containing
          scientific data

    :Required knowledge:
        Some form of background in scientific computing.

    :Optional knowledge:
        Knowledge of HDF5 or Chapel would be a plus.

    :Mentor(s):
        Michael Ferguson


.. topic:: Cryptography Library

   :Description:
        Implement a library that provides common cryptographic algorithms and
        protocols, such as those provided in OpenSSL or libsodium.


   :Expected results:
        A new cryptography module in Chapel that provides an interface to
        common algorithms and protocols, such as in OpenSSL or
        libsodium.

        - https://www.openssl.org/
        - https://download.libsodium.org/doc/

   :Required knowledge:
       * Experience or knowledge with cryptography

   :Optional knowledge:
       * Chapel
       * C/C++

   :Mentor(s):
        Andrea Francesco Iuorio


.. topic:: Linear Algebra Library

   :Description:
        Chapel currently supports linear algebra through BLAS/LAPACK-wrappers.
        This project involves implementing a linear algebra library from the
        ground up, supporting distributed operations on dense and sparse
        matrices in native Chapel code.

   :Expected results:
        A new linear algebra module or extension to the existing linear algebra
        library, that supports some subset of the operations available in BLAS
        or LAPACK.

   :Required knowledge:

       * Strong in one or more programming languages

   :Optional knowledge:

       * Chapel
       * Familiarity with parallelism

   :Mentor(s):
       Engin Kayraklioglu, Ben Albrecht


.. topic:: Distributed Data Structures Library

   :Description:
        Build a library of distributed data structures such as stacks, queues,
        linked lists, etc., and optimize the performance of their operations.

   :Expected results:
        A new distributed data structures module.

   :Required knowledge:

       * Strong in one or more programming languages

   :Optional knowledge:

       * Chapel
       * Familiarity with parallelism

   :Mentor(s):
       Engin Kayraklioglu


Compatibility
-------------

.. topic:: Chapel Online

    :Description:
        Build a web service that compiles Chapel code online
        and returns the output. Alternatively, this could be done as a
        contribution to an existing website that supports other languages.

        Some examples of this are:

        * https://ideone.com/
        * https://www.remoteinterview.io/online-c-compiler
        * http://cpp.sh/

    :Expected results:
        A web service that compiles and runs Chapel code online.

    :Required knowledge:

        * Bash
        * HTML
        * CSS
        * Javascript

    :Optional knowledge:

        * Chapel
        * Any libraries or frameworks that you might utilize, e.g. Node.js

    :Mentor(s):
        Ben Albrecht

.. topic:: Jupyter kernel for Chapel

    :Description:
        Currently, the Chapel interpreter is in its early infancy. We fully
        expect to contribute a Jupyter kernel with our interpreted version. In
        the meantime, we would like to contribute a Jupyter kernel for the
        compiled implementation, laying the groundwork for the future
        interpreted Chapel kernel.

        Some information and examples:

            * http://bollwyvl.github.io/jupyter.github.io/kernels/
            * https://github.com/brendan-rius/jupyter-c-kernel

    :Expected results:
        A functioning Jupyter kernel for Chapel

    :Required knowledge:

        * Experience with IPython Notebook / Jupyter
        * Python
        * Bash

    :Optional knowledge:

        * ZeroMQ
        * Chapel

    :Mentor(s):
        Ben Albrecht

Compiler
--------

.. topic:: Improve LLVM Support

    :Description:

        * Take steps to make the generated LLVM IR follow best practices
        * Add loop vectorization hints
        * Improve type-based alias analysis metadata
        * Annotate load instructions in LLVM to indicate when the load is from
          constant memory
        * Investigate integrating Chapel with the Polly polyhedral optimizer
        * Experiment with alternative alias analysis implementations, such as
          cfl-aa

    :Expected results:
        Improvements to the LLVM code generation capability of the Chapel
        compiler. Hopefully this also includes performance improvements for some
        Chapel programs compiled with ``--llvm``.

    :Required knowledge:

        * C++
        * LLVM

    :Mentor(s):
        Michael Ferguson

Runtime
-------

.. topic:: RCU Runtime Support

   :Description:
       RCU (read-copy update) is a strategy for managing a data structure in a
       multithreaded environment. RCU has a long history of use in the linux
       kernel and is applicable to data structures that don't need strong
       consistency guarantees. See
       `this article <https://lwn.net/Articles/262464/>`_ for more information.

       This project involves using RCU in the runtime. It can be broken
       into two components:

       1. Closing memory leaks in privatized arrays. The Chapel implementation
       creates local copies of certain objects in order to optimize
       communication. These local copies are assigned integer values and stored
       in an array managed by the C runtime. Due to the potential for data
       races, this array is never freed, even if it is re-allocated when it
       needs to be larger.

       2. Investigating whether or not RCU can be applied to the cache for
       remote data runtime component. The cache for remote data is a software
       cache in the Chapel runtime that caches data stored on remote locales.
       In some ways it is similar to the page cache in linux, which is
       implemented with RCU.

    :Expected results:
        Demonstrate how RCU can be applied to the Chapel runtime. Implement
        improvements to privatized arrays so that they no longer leak memory.
        Investigate whether or not RCU is a good fit for the cache for remote
        data, and if it is, begin effort to adjust the implementation.


    :Required knowledge:
        Familiarity with multi-threaded programming with RCU, either in the
        Linux kernel or in user-space, is required.

    :Mentor(s):
        Michael Ferguson

Infrastructure
--------------

.. topic:: Improving Testing Framework

    :Description:
        The Chapel testing system is a key piece of technology for the Chapel
        developer. We use it as a harness for doing test-driven development,
        for performing sanity checks on code before committing it, for bug and
        issue tracking, and for nightly correctness and performance regression
        testing. This testing system is described in detail
        `here <https://github.com/chapel-lang/chapel/blob/master/doc/rst/developer/bestPractices/TestSystem.rst>`_.
        This project involves implementing a variety of improvements in the
        testing framework. Some examples include:

        - Using a single test configuration file (yaml) instead of one file per
          configuration field.
        - Deprecating ``util/test/sub_test``, merging its functionality into
          ``util/start_test``.
        - Python3 support in the test framework.
        - Adding a suite of unit tests for the test framework (yes, writing
          tests for tests).

    :Expected results:
        An improvement in the usability, maintenance, and functionality of the
        Chapel testing framework.

    :Required knowledge:
        * Python
        * Bash

    :Optional knowledge:
        * Familiarity with other testing frameworks
        * Perl

    :Mentor(s):
        Ben Albrecht



..  Tools
    -----

    .. topic:: chplvis