[MESOS-8676] Fix os::read and os::write to use HANDLES

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.6.0
• Labels: stout windows
• Target Version/s: 1.6.0
• Epic Link: libprocess-iocp
• Assignee: Andrew Schwartzmeyer
• Reporter: Andrew Schwartzmeyer
• Shepherd: Andrew Schwartzmeyer
• Created: 14/Mar/18 20:50
• Updated: 02/May/18 02:31
• Resolved: 02/May/18 02:31

Description

When fixing os::open to open real Windows HANDLE s to files in a default overlapped mode, we'll need to fix os::read and os::write to work with these. Since these functions are inherently synchronous, we'll just use overlapped I/O but wait for completion, making the action synchronous.

Caveat: when files on Windows are opened in overlapped mode, they no longer retain state about the offset. Because these functions currently use the CRT APIs _read and _write, they act like POSIX file descriptors which are advanced by N bytes per read and write. We can mimic this behavior by saving the offset state in the WindowsFD abstraction.

Also fix use of WSAGetLastError since not all reads/writes are on sockets. See MESOS-8861

Issue Links

• blocks: MESOS-8670 Implement `process::io::read/write` using Thread Pool API
• blocks: MESOS-8675 Remove FD_CRT from WindowsFD
• is related to: MESOS-8682 Remove remaining CRT functions stout on Windows