Changes between Version 7 and Version 8 of SoC2015

Timestamp:

Jan 30, 2015, 1:08:54 AM (8 years ago)

Author:

Niall Douglas

Comment:

Added AFIO project ideas.

SoC2015

@@ -102 +102 @@
 Submission of the programming test should be via copying and pasting the parts you wrote into the end of the proposal you submit to Google Melange. Do NOT copy and paste the entire class or whole files! 
 
+
+=== 2. Asynchronous file i/o backend for Linux, FreeBSD, Mac OS X or WinRT ===
+Potential mentors: Niall Douglas
+
+==== Background ====
+A library called Boost.AFIO implementing portable asynchronous file i/o was ported to Boost during GSoC 2013 ([https://boostgsoc13.github.io/boost.afio/ documentation], [https://github.com/BoostGSoC13/boost.afio github]). It provides a fully asynchronous backend for the NT kernel directly using the NT kernel API, plus a generic POSIX backend which generates concurrency in the filing system using a thread pool of workers. It does not yet provide native asynchronous backends for Linux (KAIO), FreeBSD (POSIX AIO + kqueues), Mac OS X (unsure if this is technically feasible) nor WinRT.
+
+==== GSoC project proposal ====
+1. For a Linux backend: To draw up a design document describing how the afio::async_file_io_dispatcher_base interface should be implemented using a Linux KAIO API. [https://raw.githubusercontent.com/BoostGSoC13/boost.afio/master/reference/Linux%20KAIO/linux-kaio.txt You can find more information about the Linux KAIO API here]. Note that the Linux KAIO API is only partially asynchronous, and therefore will need to still be combined with a thread pool - therefore some elements of afio::async_file_io_dispatcher_compat ought to be reused, perhaps even subclassed.
+
+ For a FreeBSD backend: To draw up a design document describing how the afio::async_file_io_dispatcher_base interface should be implemented using a combination of the [https://www.freebsd.org/cgi/man.cgi?query=lio_listio&sektion=2&apropos=0&manpath=FreeBSD+10.1-RELEASE POSIX AIO API] and the [https://www.freebsd.org/cgi/man.cgi?query=kqueue kqueue EVFILT_AIO] event watcher via which completions of asynchronous file operations are notified back to AFIO. As the POSIX AIO API only covers reading and writing, it will almost certainly subclass afio::async_file_io_dispatcher_compat.
+
+ For a Mac OS X backend: OS X lacks the kqueue EVFILT_AIO interface, and therefore requires POSIX AIO clients to be notified of completions via signals. This probably makes a native backend for OS X technically infeasible, but feel free to submit a proposal proving me wrong!
+
+ For a WinRT backend: To draw up a design document describing how the afio::async_file_io_dispatcher_base interface should be implemented using the WinRT API. WinRT provides a rich suite of fully asynchronous file i/o APIs ([https://msdn.microsoft.com/en-us/library/windows/apps/xaml/windows.storage.fileio.aspx see Windows.Storage]), and when combined with [http://blogs.msdn.com/b/vcblog/archive/2014/11/12/resumable-functions-in-c.aspx the experimental C++ 17 resumable functions support in Visual Studio 2015] it should make the implementation of this backend quite straightforward. 
+
+2. To implement one of the above designs.
+
+3. To write unit, functional and performance regression testing for all of the above, including exception safety testing and multi threaded testing, to a 100% code coverage level (excluding fatal abort handling code).
+
+4. To write documentation to Boost quality levels for the new backend, including benchmarking the new backend against the compatibility backend under cold, warm and semi-warm file cache conditions on magnetic and solid state storage devices.
+
+==== Potential project extension funded by Boost ====
+1. Fast, scalable portable directory contents change monitoring.
+
+2. Extended attributes support.
+
+3. ACL support.
+
+4. A Filesystem TS and iostreams wrapper for AFIO.
+
+==== Programming competency test ====
+Using [http://www.boost.org/doc/libs/1_57_0/doc/html/boost_asio.html Boost.ASIO] (not AFIO!), write a program which registers a Linux KAIO, FreeBSD POSIX AIO + kqueues or WinRT asynchronous file i/o operation with ASIO (either a file read or a file write). ASIO should invoke a handler which prints to stdout "Hello file i/o completion" when the asynchronous file i/o operation completes.
+
+
 == Self-contained standalone GSoC Projects (no competency test) ==
 The following projects have been suggested by potential mentors. Selecting one of these, in consultation with the [http://www.boost.org/community/groups.html#main Boost developers mailing list], provides the highest chance that a mentor can be found for your GSoC project proposal. You should only choose one of these proposals if you already have at least 1,000 lines of C++ library code out there we can examine for your programming competency, otherwise your proposal cannot be preferentially ranked (see above). Make SURE you provide a link to your existing C++ code base in the proposal you submit to Melange. A template for the proposal can be found [wiki:SoCSubmissionTemplate here].
-
 
 === 1. Boost.odeint Implicit Routines ===