concurrencyts

C++ Concurrency TS minimal implementation.

This is a bare-bones implementation of the Concurrency TS. A simple if terse documentation is available here.

This implementation provides the following abstractions.

1. future with then continuations, corresponding promise (concurrencyts::future in future.h).
2. An implementation of async that returns futures of the above kind (concurrencyts::async in future.h).
3. when_all for waiting on multiple futures till all are set (concurrencyts::when_all in future.h).
4. when_any akin to when_all but signaled as soon as any one future is ready.
5. latch for waiting till N threads have signaled the latch object (concurrencyts::latch in latch.h).
6. barrier and flex_barrier for upto N threads to block till all N have arrived (concurrencyts::barrier and concurrencyts::flex_barrier in barrier.h). Only arrive_and_wait is implemented, while arrive_and_drop is missing.

The rest of the abstractions are absent. While I intend to add them, I don't have a fixed schedule for doing so.

Compatibility

You can use this library with a compiler that supports C++14 or later. It will possibly work with C++11 with minor modifications (change the std::result_of_t<...>s to std::result_of<...>::type. We don't use any mostrosity beyond simple GNUMake for building. It has been tested with g++/libstdc++ as well as clang++/libc++ on Linux. It works unchanged with C++17 and C++20.

Building

The library is entirely header-only, and doesn't use any virtual functions, etc. Thus in order to use the future-related functionality, you just include the header future.h, and get all symbols from the namespace concurrencyts. Likewise with the other headers.

If you would rather use the std::experimental namespace, just #include "concurrencyts.h". Don't include any other header individually.

You can check example usages of the abstractions by looking at the corresponding .cc files. You can also build and run them using:

make bin/future
make bin/latch
make bin/barrier

There are no formal unit tests, but I intend to add them soon.