https://gitlab.synchro.net/main/sbbs/-/commit/031df44f62dd9ac0040a2a27
Added Files:
src/Directory.Build.props
Modified Files:
docs/v322_new.md
Log Message:
Windows: raise FD_SETSIZE to 1024 for all MSBuild projects

Winsock defaults FD_SETSIZE to 64, and nothing in the tree raised it.
FD_SET() silently discards every socket past the 64th, after which
select() can never report it ready.

The JS event loop reaches that ceiling: js_internal.cpp polls its event
list with select() on Windows (the poll() alternative is compiled only
where PREFER_POLL is defined, which src/build/Common.gmake does for
non-Win32 builds only, since 663ca552e6, 2021-03-31). Events are
inserted at the head of the list and the fill loop walks it forward, so
the oldest event is the first one dropped -- for a JS server that is the listening socket registered at startup. A Win32 JS server holding 64+
sockets therefore stops accepting new connections entirely while every established connection keeps working, and the kernel still completes the
TCP handshake from the listen backlog, so it presents as a network fault
rather than a server one.

Reachable since the socket-callback event loop landed in 1928973941 (2021-04-02); ircd.js moved its accept path into it in d7cb93923c
(2021-05-22), before which it polled its listeners directly each pass.
Observed on vert.synchro.net, a Win32 IRCd hub with 57 server links.

The value has to be identical in every translation unit -- fd_set is
{ u_int fd_count; SOCKET fd_array[FD_SETSIZE]; }, and sbbs.h exports js_socket_add()/js_socket_isset(), which take fd_set* across the
sbbs.dll boundary -- so it is set in src/Directory.Build.props, which
also covers xpdev for the solutions that build it outside sbbs3.sln.
Redefining FD_SETSIZE is explicitly supported by winsock2.h, and
ws2_32.dll tolerates the larger struct because select() and
__WSAFDIsSet() only walk fd_count entries.

Switching Windows to poll()/WSAPoll() instead is the other candidate
fix; see issue #1212 for what currently stands in the way.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

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