SocketServer should set SO_REUSEPORT along with SO_REUSEADDR when present

[AndyZeldis]

BPO	16594
Nosy	@gvanrossum, @asvetlov, @aisk
PRs	bpo-16594: Add allow_reuse_port on socketserver #30072
Files	osc-broadcast-rcv.py: SocketServer broadcast receive workaround

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2021-12-13.13:33:49.165>
created_at = <Date 2012-12-02.09:07:29.427>
labels = ['type-bug', 'library', '3.11']
title = 'SocketServer should set SO_REUSEPORT along with SO_REUSEADDR when present'
updated_at = <Date 2021-12-13.13:33:49.164>
user = 'https://bugs.python.org/AndyZeldis'

bugs.python.org fields:

activity = <Date 2021-12-13.13:33:49.164>
actor = 'asvetlov'
assignee = 'none'
closed = True
closed_date = <Date 2021-12-13.13:33:49.165>
closer = 'asvetlov'
components = ['Library (Lib)']
creation = <Date 2012-12-02.09:07:29.427>
creator = 'Andy.Zeldis'
dependencies = []
files = ['28183']
hgrepos = []
issue_num = 16594
keywords = ['patch']
message_count = 3.0
messages = ['176777', '205125', '408447']
nosy_count = 4.0
nosy_names = ['gvanrossum', 'asvetlov', 'Andy.Zeldis', 'asaka']
pr_nums = ['30072']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue16594'
versions = ['Python 3.11']

[AndyZeldis]

On BSD (including Mac OS X) SO_REUSEPORT should be specified along with SO_REUSEADDR to match behavior on Linux (and possible Windows). This is needed to have multiple listeners to a UDP broadcast.

I discovered this when using PyOSC. Attached is an example modified to subclass SocketServer with a workaround. It should be possible to start multiple instances of this program, all of which will receive messages to a broadcast address (eg 255.255.255.255:7110).

This test uses Python 2.7 on OS X (despite the "python3" shebang line from the example)

[gvanrossum]

Note: it is possible that SO_REUSEPORT is defined yet not implemented (and you'll get an OSError when using it).

[asvetlov]

New changeset b56774b by AN Long in branch 'main':
bpo-16594: Add allow_reuse_port on socketserver (GH-30072)
b56774b