[Mingw-w64-public] Missing: Ideal send backlog (ISB) control codes for WSAIoctl

[Sharadh R. <sh...@pe...>]

Hi, MinGW-w64 developers;

Two control codes for the WSAIoctl function, 
SIO_IDEAL_SEND_BACKLOG_QUERY and 
SIO_IDEAL_SEND_BACKLOG_CHANGE 
are not implemented in MinGW-w64. 

These are available in <ws2ipdef.h> from the Windows SDK.

Additionally, there are two wrapper functions, 
int idealsendbacklogquery(_In_ SOCKET, _OUT ULONG*) and
int idealsendbacklognotify(_In_ SOCKET, _In_opt_ LPWSAOVERLAPPED, _In_opt_ LPWSAOVERLAPPED_COMPLETION_ROUTINE)

These are available in <WS2tcpip.h> from the Windows SDK. 

All of the above are detailedin the Microsoft documentation below:
https://learn.microsoft.com/en-gb/windows/win32/winsock/sio-ideal-send-backlog-query and
https://learn.microsoft.com/en-gb/windows/win32/winsock/sio-ideal-send-backlog-change

We’ve been working with Microsoft’s Azure SDK for C++ (https://github.com/Azure/azure-sdk-for-cpp), 
which uses QUERY here: 
https://github.com/Azure/azure-sdk-for-cpp/blob/55c241902d6897f9c8b9aee2668c76c5d0723ba4/sdk/core/azure-core/src/http/curl/curl.cpp#L192
This fails to compile under MinGW-w64.

There appears to be a work-around in libcurl here: https://github.com/curl/curl/blob/ff92e3b13ce34f8c00410eea0ffbba4d7c20e679/lib/cf-socket.c#L1478

It would be good to have all these macros and functions available in MinGW-w64. 

Thanks!

Regards
Sharadh Rajaraman