Set TCP listener created sockets to non blocking

[ThadHouse]

Description

TCP listener sockets on linux were not set to non-blocking. So they'd block on read 😱

Built on top of #4537 as I'm interacting at the exact same point. See the fcntl call.

Testing

I'm trying to figure out how to write a test for this. I have an idea, but not sure the right variables are exposed to the test framework.

Documentation

N/A

[nibanks]

There are conflicts that must be resolved, AND these build errors:

/__w/msquic/msquic/src/platform/datapath_epoll.c: In function 'CxPlatSocketContextAcceptCompletion':
/__w/msquic/msquic/src/platform/datapath_epoll.c:1582:9: error: implicit declaration of function 'fcntl' [-Werror=implicit-function-declaration]
 1582 |         fcntl(
      |         ^~~~~
/__w/msquic/msquic/src/platform/datapath_epoll.c:1584:13: error: 'F_SETFL' undeclared (first use in this function)
 1584 |             F_SETFL, fcntl(SocketContext->AcceptSocket->SocketContexts[0].SocketFd, F_GETFL, 0) | O_NONBLOCK);
      |             ^~~~~~~
/__w/msquic/msquic/src/platform/datapath_epoll.c:1584:13: note: each undeclared identifier is reported only once for each function it appears in
/__w/msquic/msquic/src/platform/datapath_epoll.c:1584:85: error: 'F_GETFL' undeclared (first use in this function)
 1584 |             F_SETFL, fcntl(SocketContext->AcceptSocket->SocketContexts[0].SocketFd, F_GETFL, 0) | O_NONBLOCK);
      |                                                                                     ^~~~~~~
/__w/msquic/msquic/src/platform/datapath_epoll.c:1584:99: error: 'O_NONBLOCK' undeclared (first use in this function); did you mean 'EFD_NONBLOCK'?
 1584 |             F_SETFL, fcntl(SocketContext->AcceptSocket->SocketContexts[0].SocketFd, F_GETFL, 0) | O_NONBLOCK);
      |                                                                                                   ^~~~~~~~~~
      |                                                                                                   EFD_NONBLOCK

[ThadHouse]

Merged and fixed.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.83%. Comparing base (376265a) to head (863573d).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4541      +/-   ##
==========================================
+ Coverage   85.08%   85.83%   +0.74%     
==========================================
  Files          56       56              
  Lines       15537    15537              
==========================================
+ Hits        13220    13336     +116     
+ Misses       2317     2201     -116     

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[nibanks]

More build failures:

/home/runner/work/msquic/msquic/src/platform/datapath_epoll.c: In function ‘CxPlatSocketContextAcceptCompletion’:
/home/runner/work/msquic/msquic/src/platform/datapath_epoll.c:1585:5: error: ‘Flags’ undeclared (first use in this function)
 1585 |     Flags =
      |     ^~~~~
/home/runner/work/msquic/msquic/src/platform/datapath_epoll.c:1585:5: note: each undeclared identifier is reported only once for each function it appears in
/home/runner/work/msquic/msquic/src/platform/datapath_epoll.c:1615:9: error: label ‘Exit’ used but not defined
 1615 |         goto Exit;
      |         ^~~~

[ThadHouse]

Ill fix the break tonight.