internal/socket: support MSG_DONTWAIT

Explicitly handle MSG_DONTWAIT in read and send calls on platforms where this is defined, to get the per-call non-blocking behavior as would be expected when calling readmsg/sendmsg in C.
When MSG_DONTWAIT is set, we always return true from the function passed to syscall.RawConn.Read/Write, to avoid entering the polling state.

Fixes golang/go#46891

Change-Id: I4809577477554db1c45b6f4825a03d98208199d7
GitHub-Last-Rev: 4022e9b52c4375536e23162a88e5aa4d5637f134
GitHub-Pull-Request: golang/net#108
Reviewed-on: https://go-review.googlesource.com/c/net/+/333469
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Trust: Damien Neil <dneil@google.com>
5 files changed
tree: 0fc98c127a5ee3acb007b13ed1687cbcf37e19aa
  1. bpf/
  2. context/
  3. dict/
  4. dns/
  5. html/
  6. http/
  7. http2/
  8. icmp/
  9. idna/
  10. internal/
  11. ipv4/
  12. ipv6/
  13. lif/
  14. nettest/
  15. netutil/
  16. proxy/
  17. publicsuffix/
  18. route/
  19. trace/
  20. webdav/
  21. websocket/
  22. xsrftoken/
  23. .gitattributes
  24. .gitignore
  25. AUTHORS
  26. codereview.cfg
  27. CONTRIBUTING.md
  28. CONTRIBUTORS
  29. go.mod
  30. go.sum
  31. LICENSE
  32. PATENTS
  33. README.md
README.md

Go Networking

Go Reference

This repository holds supplementary Go networking libraries.

Download/Install

The easiest way to install is to run go get -u golang.org/x/net. You can also manually git clone the repository to $GOPATH/src/golang.org/x/net.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html. The main issue tracker for the net repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/net:” in the subject line, so it is easy to find.