cpp-channel

Go-style concurrency for C++11

Getting started

To use the library, #include <channel>. Here's an example:

void thread_a(cpp::channel<char> c) {
  c.send('A');
  char r = c.recv();

  assert('B' == r);
}

void thread_b(cpp::channel<char> c) {
  char r = c.recv();
  c.send('B');

  assert('A' == r);
}

int main() {
  cpp::channel<char> c;

  std::thread a(thread_a, c);
  std::thread b(thread_b, c);

  a.join();
  b.join();

  return EXIT_SUCCESS;
}

As in Go, cpp::channel<T, N> are first-class values. In particular, channel c in the example is passed by value to the newly created threads.

The source code repository contains several more examples including the most standard one of them all, Dijkstra's dining philosophers. In fact, it also shows the use of std::ref for a dining_table struct as these are typically not passed by value.

Documentation

A cpp::channel<T, N> is like a Go channel created with make(chan T, N). If N is zero, the channel is synchronous; otherwise, it is asynchronous, as documented in the Go language specification:

• http://golang.org/ref/spec#Channel_types
• http://golang.org/ref/spec#Send_statements
• http://golang.org/ref/spec#Receive_operator

But to simplify the library usage, cpp::channel cannot be nil nor closed.

Similar to Go, there are cpp::ichannel<T, N> and cpp::ochannel<T, N> that can only receive and send elements of type T, respectively.

Noteworthy, channels are first-class values. Consequently, we can have channels of channels.

Installation

You only need a C++11-compliant compiler. There are no other external dependencies.

To build the library on a (mostly) POSIX-compliant operating system, execute the following commands from the cpp-channel directory:

$ ./autogen.sh
$ ./configure
$ make
$ make test
$ make install

If make test fails, you can still install, but it is likely that some features of this library will not work correctly on your system. Proceed at your own risk.

Note that make install may require superuser privileges.

The troubleshooting section below has a few additional tips. For advanced configuration options refer to the Autoconf documentation.

Troubleshooting

If make test fails with an error that indicates that libstdc++.so.6 or a specific version of GLIBCXX cannot be found, then check out GCC's FAQ.

Bug Reports

You are warmly invited to submit patches as Github pull request, formatted according to the existing coding style.