IOCP WSARecv always return error 10022

Question

I'm using IOCP on Windows. Previously I used method GetQueuedCompletionStatus to poll the queue and everything was fine. But when I decided to refactor the logic in the way to utilize completion routine with WSARecv call it always fails with the error WSAEINVAL (10022). This code is in thread created with CreateTread

int flags = 0;
m_iocport = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, NULL, 0);
handle = CreateIoCompletionPort(clientSocket, m_iocport, 0, 0);
OVERLAPPED_EX *over = new OVERLAPPED_EX();
result = WSARecv(clientSocket, &over->m_wsabuf, 1, NULL, &flags, over, WorkerRoutine);

And the worker routine is empty and has following definition:

void static CALLBACK WorkerRoutine(DWORD Error, DWORD BytesTransferred, LPWSAOVERLAPPED Overlapped, DWORD InFlags) {}

When I pass NULL instead of WorkerRoutine to the WSARecv method everything works fine. But when I pass completion routine to the call it fails with the error 10022. I tried to use WorkerRoutine and &WorkerRoutine nothing helps.

the hEvent property is set to NULL in the OVERLAPPED_EX object.

RbMm · Accepted Answer · 2017-10-23T19:05:20.490

4

the I/O completion port associated with file and lpCompletionRoutine this is mutually exclusive parameters. you can not use it both at once. when you do this - kernel return STATUS_INVALID_PARAMETER which is translated to WSAEINVAL. so you and must got exactly this error.

the IOCP and ApcRoutine 2 different ways for notify you about operation complete. when you use IOCP - system send packet to IOCP on complete. you need use GetQueuedCompletionStatus or NtRemoveIoCompletion to extract this packet later. and this is not "poll". from another side if you use ApcRoutine system insert apc to your thread. use two ways for notify at once and in concurrent - this is logic error and kernel correct doing when return to you STATUS_INVALID_PARAMETER in this case.

unfortunately this is not clear stated in MSDN or how minimum i can not fount this. but some research + WRK source code help understand this situation:

WSARecv internally call ZwDeviceIoControlFile and as result in kernel called IopXxxControlFile. when lpCompletionRoutine != 0 the ApcRoutine parameter for IopXxxControlFile is present and you fail exactly at this point:

    //
    // If this file has an I/O completion port associated w/it, then ensure
    // that the caller did not supply an APC routine, as the two are mutually
    // exclusive methods for I/O completion notification.
    //

    if (fileObject->CompletionContext && IopApcRoutinePresent( ApcRoutine )) {
        ObDereferenceObject( fileObject );
        return STATUS_INVALID_PARAMETER;
}

also you can allocate m_wsabuf in stack. valid must be only buffer to which point WSABUF

If this function is completed in an overlapped manner, it is the Winsock service provider's responsibility to capture the WSABUF structures before returning from this call. This enables applications to build stack-based WSABUF arrays pointed to by the lpBuffers parameter.

so you can place to OVERLAPPED_EX only buffer to which point WSABUF.buf but not whole WSABUF. but this already not related to your error

edited Oct 23 '17 at 19:05

answered Oct 23 '17 at 18:39

RbMm

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This is not about the files, `clientSocket` tells about sockets. Also here I found example http://www.winsocketdotnetworkprogramming.com/winsock2programming/winsock2advancediomethod5g.html which shows how to use WorkerRoutine with Events and it works. From other side MSDN disagree with them https://msdn.microsoft.com/en-us/library/windows/desktop/ms741688(v=vs.85).aspx So I confused – htonus Oct 23 '17 at 20:20
@htonus - socket is file. and i nothing wrote about events. i wrote that iocp and `WorkerRoutine` is mutually exclusive. remove `WorkerRoutine` (set it to 0) if you want use iocp on socket. or not bind socket to iocp if you want use `WorkerRoutine`. all what i wrote is 100% true – RbMm Oct 23 '17 at 20:25
@htonus - simply try think yourself - if you want use `WorkerRoutine` - for what you associated IO completion port with file ? you not need this. from another side - if you have IOCP on file - for what you need `WorkerRoutine` ? remove any of this 2 objects – RbMm Oct 23 '17 at 20:29
@htonus - and i look fast your example - here big logic problem. it use asynchronous `WSARecv` - this is ok. but before this it use synchronous call `accept` (which is wait) which is kill all logic. if you need asynchronous io - use only `AcceptEx` here – RbMm Oct 23 '17 at 20:37
Yes I know that. In my application I use accept on non blocking socket. So It doesn't block execution. Either way, thanks for you comments. – htonus Oct 23 '17 at 20:49
@htonus - `accept` is block execution or fail. this is visible simply from it signature. it return `SOCKET`. and no way return it in asynchronous. only `AcceptEx` or synchronous call – RbMm Oct 23 '17 at 20:52
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/157315/discussion-between-htonus-and-rbmm). – htonus Oct 23 '17 at 21:02

IOCP WSARecv always return error 10022

1 Answers1