Why timeout param doesn't work in GetAddrInfoExW()? - winapi

Question

When I try to call:
timeval timeout{ 0, 999 };
::GetAddrInfoExW(L"my_name", L"", NS_DNS, nullptr, nullptr, &pResult, &timeout, nullptr, nullptr, nullptr);
I got 10022 "Invalid params".
However, if I replace "&timeout" with "nullptr", I got 0 (OK).
Why the timeout causes EINVAL error?
UNICODE macro is defined, my system is Windows 10.

Answer 1

if timeout not 0, the lpOverlapped must be also not 0. the code can be next
#include <ws2tcpip.h>
struct QUERY_CONTEXT : OVERLAPPED
{
PADDRINFOEX _pResult;
ULONG _dwThreadId = GetCurrentThreadId();
~QUERY_CONTEXT()
{
if (PADDRINFOEX pResult = _pResult)
{
FreeAddrInfoEx(_pResult);
}
}
static void CALLBACK QueryCompleteCallback(
_In_ ULONG dwError,
_In_ ULONG /*dwBytes*/,
_In_ OVERLAPPED* lpOverlapped
)
{
static_cast<QUERY_CONTEXT*>(lpOverlapped)->OnComplete(dwError);
}
void OnComplete(_In_ ULONG dwError)
{
DbgPrint("OnComplete(%u)\n");
if (PADDRINFOEX pResult = _pResult)
{
do
{
WCHAR buf[64];
ULONG len = _countof(buf);
if (!WSAAddressToStringW(pResult->ai_addr, (ULONG)pResult->ai_addrlen, 0, buf, &len))
{
DbgPrint("%S\n", buf);
}
} while (pResult = pResult->ai_next);
}
PostThreadMessageW(_dwThreadId, WM_QUIT, dwError, 0);
delete this;
}
ULONG Query(_In_ PCWSTR pName, _In_opt_ timeval *timeout)
{
ULONG dwError = GetAddrInfoExW(pName, 0, NS_DNS, 0, 0,
&_pResult, timeout, this, QueryCompleteCallback, 0);
//
// If GetAddrInfoExW() returns WSA_IO_PENDING, GetAddrInfoExW will invoke
// the completion routine. If GetAddrInfoExW returned anything else we must
// invoke the completion directly.
//
if (dwError != WSA_IO_PENDING)
{
QueryCompleteCallback(dwError, 0, this);
}
return dwError;
}
};
///////////////////////////////////////
WSADATA wd;
if (NOERROR == WSAStartup(WINSOCK_VERSION, &wd))
{
if (QUERY_CONTEXT* pqc = new QUERY_CONTEXT {})
{
timeval timeout{ 1 };
pqc->Query(L"stackoverflow.com", &timeout);
}
MessageBoxW(0, 0, 0, 0);
WSACleanup();
}
also for dns query more efficient direct use DnsQueryEx function (GetAddrInfoExW internally call DnsQueryEx, but before this - alot of another code executed)