static int
WaitForConnect(
    TcpState *statePtr,		/* State of the socket. */
    int *errorCodePtr)		/* Where to store errors? A passed
				 * null-pointer activates background mode. */
{
    int result;
    int oldMode;

    /*
     * Check if an async connect failed already and error reporting is
     * demanded, return the error ENOTCONN.
     */

    if (errorCodePtr != NULL && GOT_BITS(statePtr->flags, TCP_ASYNC_FAILED)) {
	*errorCodePtr = ENOTCONN;

	return -1;
    }

    /*
     * Be sure to disable event servicing so we are truly modal.
     */

    oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE);
    int oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE);

    /*
     * Loop in the blocking case until the connect signal is present
     */

    while (1) {
	/*

	    SetEvent(tsdPtr->socketListLock);

	    /*
	     * Continue connect. If switched to synchronous connect, the
	     * connect is terminated.
	     */

	    result = TcpConnect(NULL, statePtr);
	    int result = TcpConnect(NULL, statePtr);

	    /*
	     * Restore event service mode.
	     */

	    (void) Tcl_SetServiceMode(oldMode);

    void *instanceData,		/* Socket state. */
    char *buf,			/* Where to store data read. */
    int bufSize,		/* How much space is available in the
				 * buffer? */
    int *errorCodePtr)		/* Where to store error code. */
{
    TcpState *statePtr = (TcpState *)instanceData;
    int bytesRead;
    DWORD error;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    TclThreadDataKeyGet(&dataKey);

    *errorCodePtr = 0;

    /*
     * First check to see if EOF was already detected, to prevent calling the

     * No EOF, and it is connected, so try to read more from the socket. Note
     * that we clear the FD_READ bit because read events are level triggered
     * so a new event will be generated if there is still data available to be
     * read. We have to simulate blocking behavior here since we are always
     * using non-blocking sockets.
     */

    int bytesRead;
    while (1) {
	SendSelectMessage(tsdPtr, UNSELECT, statePtr);

	/*
	 * Single fd operation: this proc is only called for a connected
	 * socket.
	 */

	if (GOT_BITS(statePtr->readyEvents, FD_CLOSE)) {
	    SET_BITS(statePtr->flags, SOCKET_EOF);
	    bytesRead = 0;
	    break;
	}

	error = WSAGetLastError();
	DWORD error = WSAGetLastError();

	/*
	 * If an RST comes, then ignore the error and report an EOF just like
	 * on Unix.
	 */

	if (error == WSAECONNRESET) {

TcpOutputProc(
    void *instanceData,		/* Socket state. */
    const char *buf,		/* The data buffer. */
    int toWrite,		/* How many bytes to write? */
    int *errorCodePtr)		/* Where to store error code. */
{
    TcpState *statePtr = (TcpState *)instanceData;
    int written;
    DWORD error;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
	    TclThreadDataKeyGet(&dataKey);

    *errorCodePtr = 0;

    /*
     * Check if there is an async connect running.
     * For blocking sockets terminate connect, otherwise do one step.
     * For a non blocking socket return EWOULDBLOCK if connect not terminated
     */

    if (WaitForConnect(statePtr, errorCodePtr) != 0) {
	return -1;
    }

    int written;
    while (1) {
	SendSelectMessage(tsdPtr, UNSELECT, statePtr);

	/*
	 * Single fd operation: this proc is only called for a connected
	 * socket.
	 */

	/*
	 * Check for error condition or overflow. In the event of overflow, we
	 * need to clear the FD_WRITE flag so we can detect the next writable
	 * event. Note that Windows only sends a new writable event after a
	 * send fails with WSAEWOULDBLOCK.
	 */

	error = WSAGetLastError();
	DWORD error = WSAGetLastError();
	if (error == WSAEWOULDBLOCK) {
	    CLEAR_BITS(statePtr->readyEvents, FD_WRITE);
	    if (GOT_BITS(statePtr->flags, TCP_NONBLOCKING)) {
		*errorCodePtr = EWOULDBLOCK;
		written = -1;
		break;
	    }

TcpSetOptionProc(
    void *instanceData,		/* Socket state. */
    Tcl_Interp *interp,		/* For error reporting - can be NULL. */
    const char *optionName,	/* Name of the option to set. */
    const char *value)		/* New value for option. */
{
    TcpState *statePtr = (TcpState *)instanceData;
    SOCKET sock;
    size_t len = 0;

    if (optionName != NULL) {
	len = strlen(optionName);
    }

    sock = statePtr->sockets->fd;
    SOCKET sock = statePtr->sockets->fd;

    if ((len > 1) && (optionName[1] == 'k') &&
	    (strncmp(optionName, "-keepalive", len) == 0)) {
	BOOL boolVar;
	int rtn;

	if (Tcl_GetBoolean(interp, value, &boolVar) != TCL_OK) {
	    return TCL_ERROR;
	}
	rtn = setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
	int rtn = setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
		(const char *) &boolVar, sizeof(boolVar));
	if (rtn != 0) {
	    Tcl_WinConvertError(WSAGetLastError());
	    if (interp) {
		TclPrintfResult(interp, "couldn't set socket option: %s",
			Tcl_PosixError(interp));
	    }
	    return TCL_ERROR;
	}
	return TCL_OK;
    }
    if ((len > 1) && (optionName[1] == 'n') &&
	    (strncmp(optionName, "-nodelay", len) == 0)) {
	BOOL boolVar;
	int rtn;

	if (Tcl_GetBoolean(interp, value, &boolVar) != TCL_OK) {
	    return TCL_ERROR;
	}
	rtn = setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
	int rtn = setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
		(const char *) &boolVar, sizeof(boolVar));
	if (rtn != 0) {
	    Tcl_WinConvertError(WSAGetLastError());
	    if (interp) {
		TclPrintfResult(interp, "couldn't set socket option: %s",
			Tcl_PosixError(interp));
	    }

				 * for, or NULL to get all options and their
				 * values. */
    Tcl_DString *dsPtr)		/* Where to store the computed value;
				 * initialized by caller. */
{
    TcpState *statePtr = (TcpState *)instanceData;
    char host[NI_MAXHOST], port[NI_MAXSERV];
    SOCKET sock;
    size_t len = 0;
    int reverseDNS = 0;
#define SUPPRESS_RDNS_VAR "::tcl::unsupported::noReverseDNS"
#define HAVE_OPTION(option) \
	((len > 1) && (optionName[1] == option[1]) && \
	    (strncmp(optionName, option, len) == 0))

    /*
     * Go one step in async connect
     *
     * If any error is thrown save it as background error to report eventually
     * below.
     */

    if (!GOT_BITS(statePtr->flags, TCP_ASYNC_TEST_MODE)) {
	WaitForConnect(statePtr, NULL);
    }

    sock = statePtr->sockets->fd;
    SOCKET sock = statePtr->sockets->fd;
    if (optionName != NULL) {
	len = strlen(optionName);
    }

    if (HAVE_OPTION("-error")) {
	/*
	 * Do not return any errors if async connect is running.

		    statePtr->connectError = 0;
		}
	    } else {
		/*
		 * Report an eventual last error of the socket system.
		 */

		int optlen;
		int ret;
		DWORD err;

		/*
		 * Populate the err variable with a POSIX error
		 */

		optlen = sizeof(int);
		ret = getsockopt(sock, SOL_SOCKET, SO_ERROR,
		int optlen = sizeof(int);
		int ret = getsockopt(sock, SOL_SOCKET, SO_ERROR,
			(char *)&err, &optlen);

		/*
		 * The error was not returned directly but should be taken
		 * from WSA.
		 */

		}
		return TCL_ERROR;
	    }
	}
    }

    if ((len == 0) || HAVE_OPTION("-sockname")) {
	TcpFdList *fds;
	address sockname;
	socklen_t size;
	int found = 0;

	if (len == 0) {
	    Tcl_DStringAppendElement(dsPtr, "-sockname");
	    Tcl_DStringStartSublist(dsPtr);
	}
	if (GOT_BITS(statePtr->flags, TCP_ASYNC_PENDING)) {
	    /*
	     * In async connect output an empty string
	     */

	    found = 1;
	} else {
	    for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {
		sock = fds->fd;
		size = sizeof(sockname);
	    for (TcpFdList *fds = statePtr->sockets; fds; fds = fds->next) {
		address sockname;
		socklen_t size = sizeof(sockname);
		sock = fds->fd;
		if (getsockname(sock, &(sockname.sa), &size) >= 0) {
		    int flags = reverseDNS;

		    found = 1;
		    getnameinfo(&sockname.sa, size, host, sizeof(host),
			    NULL, 0, NI_NUMERICHOST);
		    Tcl_DStringAppendElement(dsPtr, host);

			Tcl_PosixError(interp));
	    }
	    return TCL_ERROR;
	}
    }

    if ((len == 0) || HAVE_OPTION("-keepalive")) {
	int optlen;
	BOOL opt = FALSE;

	if (len == 0) {
	    sock = statePtr->sockets->fd;
	    Tcl_DStringAppendElement(dsPtr, "-keepalive");
	}
	optlen = sizeof(BOOL);
	int optlen = sizeof(BOOL);
	getsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (char *)&opt, &optlen);
	Tcl_DStringAppendElement(dsPtr, opt ? "1" : "0");
	if (len > 0) {
	    return TCL_OK;
	}
    }

    if ((len == 0) || HAVE_OPTION("-nodelay")) {
	int optlen;
	BOOL opt = FALSE;

	if (len == 0) {
	    sock = statePtr->sockets->fd;
	    Tcl_DStringAppendElement(dsPtr, "-nodelay");
	}
	optlen = sizeof(BOOL);
	int optlen = sizeof(BOOL);
	getsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (char *)&opt, &optlen);
	Tcl_DStringAppendElement(dsPtr, opt ? "1" : "0");
	if (len > 0) {
	    return TCL_OK;
	}
    }

	    /*
	     * For asynchronous connect set the socket in nonblocking mode
	     * and activate connect notification
	     */

	    if (async_connect) {
		TcpState *statePtr2;
		int in_socket_list = 0;

		/*
		 * Get statePtr lock.
		 */

		WaitForSingleObject(tsdPtr->socketListLock, INFINITE);

		/*
		 * Bugfig for 336441ed59 to not ignore notifications until the
		 * infoPtr is in the list.
		 * Check if my statePtr is already in the tsdPtr->socketList
		 * It is set after this call by TcpThreadActionProc and is set
		 * on a second round.
		 *
		 * If not, we buffer my statePtr in the tsd memory so it is
		 * not lost by the event procedure
		 */

		int in_socket_list = 0;
		for (statePtr2 = tsdPtr->socketList; statePtr2 != NULL;
		for (TcpState *statePtr2 = tsdPtr->socketList; statePtr2;
			statePtr2 = statePtr2->nextPtr) {
		    if (statePtr2 == statePtr) {
			in_socket_list = 1;
			break;
		    }
		}
		if (!in_socket_list) {

				/* Callback for accepting connections from new
				 * clients. */
    void *acceptProcData)	/* Data for the callback. */
{
    SOCKET sock = INVALID_SOCKET;
    unsigned short chosenport = 0;
    struct addrinfo *addrlist = NULL;
    struct addrinfo *addrPtr;	/* Socket address to listen on. */
    TcpState *statePtr = NULL;	/* The returned value. */
    char channelName[SOCK_CHAN_LENGTH];
    u_long flag = 1;		/* Indicates nonblocking mode. */
    const char *errorMsg = NULL;
    int optvalue, port;

    TclInitSockets();

    }

    if (!TclCreateSocketAddress(interp, &addrlist, myHost, port, 1,
	    &errorMsg)) {
	goto error;
    }

    for (struct addrinfo *addrPtr = addrlist; addrPtr != NULL;
    for (addrPtr = addrlist; addrPtr != NULL; addrPtr = addrPtr->ai_next) {
	    addrPtr = addrPtr->ai_next) {
	sock = socket(addrPtr->ai_family, addrPtr->ai_socktype,
		addrPtr->ai_protocol);
	if (sock == INVALID_SOCKET) {
	    Tcl_WinConvertError((DWORD) WSAGetLastError());
	    continue;
	}

 */

void
SocketSetupProc(
    TCL_UNUSED(void *),
    int flags)			/* Event flags as passed to Tcl_DoOneEvent. */
{
    TcpState *statePtr;
    Tcl_Time blockTime = { 0, 0 };
    const Tcl_Time blockTime = { 0, 0 };
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!GOT_BITS(flags, TCL_FILE_EVENTS)) {
	return;
    }

    /*
     * Check to see if there is a ready socket.	 If so, poll.
     */
    WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
    for (statePtr = tsdPtr->socketList; statePtr != NULL;
    for (TcpState *statePtr = tsdPtr->socketList; statePtr != NULL;
	    statePtr = statePtr->nextPtr) {
	if (GOT_BITS(statePtr->readyEvents,
		statePtr->watchEvents | FD_CONNECT | FD_ACCEPT)) {
	    Tcl_SetMaxBlockTime(&blockTime);
	    break;
	}
    }

 */

static void
SocketCheckProc(
    TCL_UNUSED(void *),
    int flags)			/* Event flags as passed to Tcl_DoOneEvent. */
{
    TcpState *statePtr;
    SocketEvent *evPtr;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!GOT_BITS(flags, TCL_FILE_EVENTS)) {
	return;
    }

    /*
     * Queue events for any ready sockets that don't already have events
     * queued (caused by persistent states that won't generate WinSock
     * events).
     */

    WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
    for (statePtr = tsdPtr->socketList; statePtr != NULL;
    for (TcpState *statePtr = tsdPtr->socketList; statePtr != NULL;
	    statePtr = statePtr->nextPtr) {
	if (GOT_BITS(statePtr->readyEvents,
		statePtr->watchEvents | FD_CONNECT | FD_ACCEPT)
		&& !GOT_BITS(statePtr->flags, SOCKET_PENDING)) {
	    SET_BITS(statePtr->flags, SOCKET_PENDING);

	    evPtr = (SocketEvent *)Tcl_Alloc(sizeof(SocketEvent));
	    SocketEvent *evPtr = (SocketEvent *)Tcl_Alloc(sizeof(SocketEvent));
	    evPtr->header.proc = SocketEventProc;
	    evPtr->socket = statePtr->sockets->fd;
	    Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL);
	}
    }
    SetEvent(tsdPtr->socketListLock);
}

    int flags)			/* Flags that indicate what events to handle,
				 * such as TCL_FILE_EVENTS. */
{
    TcpState *statePtr;
    SocketEvent *eventPtr = (SocketEvent *) evPtr;
    int mask = 0, events;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    TcpFdList *fds;
    SOCKET newSocket;
    address addr;
    int len;

    if (!GOT_BITS(flags, TCL_FILE_EVENTS)) {
	return 0;
    }

    }

    /*
     * Handle connection requests directly.
     */

    if (GOT_BITS(statePtr->readyEvents, FD_ACCEPT)) {
	for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {
	for (TcpFdList *fds = statePtr->sockets; fds != NULL; fds = fds->next) {
	    /*
	     * Accept the incoming connection request.
	     */

	    len = sizeof(address);
	    newSocket = accept(fds->fd, &(addr.sa), &len);

    WPARAM wParam,
    LPARAM lParam)
{
    int event, error;
    SOCKET socket;
    TcpState *statePtr;
    int info_found = 0;
    TcpFdList *fds = NULL;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
#ifdef _WIN64
	    GetWindowLongPtrW(hwnd, GWLP_USERDATA);
#else
	    GetWindowLongW(hwnd, GWL_USERDATA);
#endif

	    Tcl_ThreadAlert(tsdPtr->threadId);
	}
	SetEvent(tsdPtr->socketListLock);
	break;

    case SOCKET_SELECT:
	statePtr = (TcpState *) lParam;
	for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {
	for (TcpFdList *fds = statePtr->sockets; fds != NULL; fds = fds->next) {
	    if (wParam == SELECT) {
		WSAAsyncSelect(fds->fd, hwnd,
			SOCKET_MESSAGE, statePtr->selectEvents);
	    } else {
		/*
		 * Clear the selection mask
		 */

 */

static int
FindFDInList(
    TcpState *statePtr,
    SOCKET socket)
{
    TcpFdList *fds;
    for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {
    for (TcpFdList *fds = statePtr->sockets; fds != NULL; fds = fds->next) {
	if (fds->fd == socket) {
	    return 1;
	}
    }
    return 0;
}


 */

static void
TcpThreadActionProc(
    void *instanceData,
    int action)
{
    ThreadSpecificData *tsdPtr;
    TcpState *statePtr = (TcpState *)instanceData;
    int notifyCmd;

    if (action == TCL_CHANNEL_THREAD_INSERT) {
	/*
	 * Ensure that socket subsystem is initialized in this thread, or else
	 * sockets will not work.
	 */

	TclInitSockets();

	tsdPtr = TCL_TSD_INIT(&dataKey);
    }
    TcpState *statePtr = (TcpState *)instanceData;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    int notifyCmd;

    if (action == TCL_CHANNEL_THREAD_INSERT) {
	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	statePtr->nextPtr = tsdPtr->socketList;
	tsdPtr->socketList = statePtr;

	if (statePtr == tsdPtr->pendingTcpState) {
	    tsdPtr->pendingTcpState = NULL;
	}

	SetEvent(tsdPtr->socketListLock);

	notifyCmd = SELECT;
    } else {
	TcpState **nextPtrPtr;
	int removed = 0;

	tsdPtr = TCL_TSD_INIT(&dataKey);

	/*
	 * TIP #218, Bugfix: All access to socketList has to be protected by
	 * the lock.
	 */

	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	for (nextPtrPtr = &(tsdPtr->socketList); (*nextPtrPtr) != NULL;
		nextPtrPtr = &((*nextPtrPtr)->nextPtr)) {
	    if ((*nextPtrPtr) == statePtr) {
		(*nextPtrPtr) = statePtr->nextPtr;
	for (TcpState **nextPtrPtr = &tsdPtr->socketList; *nextPtrPtr != NULL;
		nextPtrPtr = &(*nextPtrPtr)->nextPtr) {
	    if (*nextPtrPtr == statePtr) {
		*nextPtrPtr = statePtr->nextPtr;
		removed = 1;
		break;
	    }
	}
	SetEvent(tsdPtr->socketListLock);

	/*