2.5 broken on OS X: module 'socket' has no attribute 'TCP_DEFER_ACCEPT'

[zmwangx]

OS X 10.11.5, Python 3.5.1, googler 2.5:

> /usr/local/Cellar/googler/2.5/bin/googler --debug --noprompt Homebrew
[DEBUG] Connecting to new host www.google.com
Traceback (most recent call last):
  File "/usr/local/Cellar/googler/2.5/bin/googler", line 579, in new_connection
    self._conn.connect()
  File "/usr/local/Cellar/googler/2.5/bin/googler", line 122, in connect
    sock.setsockopt(socket.SOL_TCP, socket.TCP_DEFER_ACCEPT, 1)
AttributeError: module 'socket' has no attribute 'TCP_DEFER_ACCEPT'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/Cellar/googler/2.5/bin/googler", line 1908, in <module>
    main()
  File "/usr/local/Cellar/googler/2.5/bin/googler", line 1882, in main
    repl = GooglerCmd(opts)
  File "/usr/local/Cellar/googler/2.5/bin/googler", line 1471, in __init__
    self._conn = GoogleConnection(self._google_url.hostname, proxy=proxy)
  File "/usr/local/Cellar/googler/2.5/bin/googler", line 530, in __init__
    self.new_connection(host, port=port, timeout=timeout)
  File "/usr/local/Cellar/googler/2.5/bin/googler", line 582, in new_connection
    raise GoogleConnectionError(msg)
__main__.GoogleConnectionError: Failed to connect to www.google.com: module 'socket' has no attribute 'TCP_DEFER_ACCEPT'.

[zmwangx]

http://linux.die.net/man/7/tcp

Apparently TCP_DEFER_ACCEPT is not only not POSIX, but also not available in Linux before 2.4.

[jarun]

OK. I'll release 2.5.1 shortly.

[jarun]

Closed by mistake.

[jarun]

I think we can safely assume either none or very small section of our users are on Linux 2.4. So I'll make this change for OS X only.

I am seeing more that 100 ms gain with this option enabled.

Can you please check if 99c1336 works for you?

[zmwangx]

TCP_DEFER_ACCEPT isn't the only problem. TCP_QUICKACK is also not available, for instance.

I don't have time to read the code and figure out what each line does, but one should really stick to POSIX. If you want to have separate code for Linux then sure, it's your call; as I said I'll no longer work on new features and this is one, so it won't be my domain.

Here's tcp(4) for you: https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man4/tcp.4.html.

[jarun]

I don't have time to read the code

I wanted to know if the version is working for you. Not asking you to review the change.

it's your call

Yes, I intend to retain the optimizations for Linux given that both are available in the recent versions. Linux 2.4 was released in Jan 2001.

Commit 77fa658 has all these optimization options enabled only for Linux. Please confirm if this works on your system and I'll make the release.

[zmwangx]

I wanted to know if the version is working for you

As said, no. Now it appears to be working.

[zmwangx]

Linux 2.4 was released in Jan 2001.

Nowhere do we mention Linux before Jan 2001 is not supported. The usual way to feature test in python is try catch.

[jarun]

Nowhere do we mention Linux before Jan 2001 is not supported.

I think we can keep arguing on this but it doesn't make practical sense. If someone comes back with reports on kernel 2.4 we'll provide a patch.

The usual way to feature test in python is try catch.

I didn't want to make extra calls when it's known to fail. I'll re-look at it later.