[PATCH] wineserver: avoid spurious FD_WRITE on repeated calls to WSAEventSelect()

[Damjan Jovanovic]

Repeated calls to WSAEventSelect() with FD_WRITE deliver
spurious FD_WRITE events, as the flag isn't held, resulting
in us unnecessarily polling the socket for writability,
despite the fact FD_WRITE should only be delivered (1) initially
on socket creation, and (2) after send[to]() fails with
EWOULDBLOCK and buffer space becomes available.

This breaks some applications (possibly #10204 and #24946).

This patch prevents the spurious FD_WRITE by always holding FD_WRITE in
WSAEventSelect()/set_socket_event(). It will be cleared from hmask in
enable_socket_event() when a real FD_WRITE needs to be delivered.

Signed-off-by: Damjan Jovanovic <damjan.jov(a)gmail.com>
---
 dlls/ws2_32/tests/sock.c | 5 ++---
 server/sock.c            | 2 +-
 2 files changed, 3 insertions(+), 4 deletions(-)

[Marvin]

Hi,

While running your changed tests, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?

Full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=62386

Your paranoid android.


=== debian10 (32 bit French report) ===

ws2_32:
sock.c:3056: Test failed: Test[1]: expected 0, got 2
sock.c:3056: Test failed: Test[2]: expected 0, got 2
sock.c:3056: Test failed: Test[1]: expected 0, got 2
sock.c:3056: Test failed: Test[2]: expected 0, got 2

=== debian10 (32 bit Japanese:Japan report) ===

ws2_32:
sock.c:3051: Test failed: Test[1]: expected 2, got 0
sock.c:3056: Test failed: Test[1]: expected 0, got 2
sock.c:3051: Test failed: Test[2]: expected 2, got 0
sock.c:3056: Test failed: Test[2]: expected 0, got 2
sock.c:3051: Test failed: Test[1]: expected 2, got 0
sock.c:3056: Test failed: Test[1]: expected 0, got 2
sock.c:3051: Test failed: Test[2]: expected 2, got 0
sock.c:3056: Test failed: Test[2]: expected 0, got 2