Is it possible to document in that header the properties of int_fd that we can rely on?
For example, it has a hash defined for use in unordered map, set, etc. It's a POD type, etc. On Wed, Nov 29, 2017 at 10:17 PM, Andrew Schwartzmeyer < and...@schwartzmeyer.com> wrote: > Hello everyone! > > I've realized that a lot of developers working in libprocess (and > elsewhere) may not know about how to handle file descriptors in a > cross-platform way for Mesos. > > IMPORTANT: You cannot just use `int`. File descriptors on Windows are > various types of handles, but not just an `int`. > > The abstraction we use in Mesos is `int_fd`, found here: > https://github.com/apache/mesos/blob/master/3rdparty/stout/ > include/stout/os/int_fd.hpp > > On non-Windows platforms, it's just an `int`. But on Windows, it's a > `WindowsFD` which can be an `int` (from the Windows CRT which we're > deprecating), a `HANDLE` (the Windows 32 API), and a `SOCKET` (from the > WinSock library). If you're curious, the implementation is here: > https://github.com/apache/mesos/blob/master/3rdparty/stout/ > include/stout/os/windows/fd.hpp > > I just want you to be aware that if you're writing code and need an `int` > file descriptor, please use `int_fd` (and include the appropriate header) > instead of `int`, as otherwise you break the Windows build. > > Thank you, > > Andy >
