tclwinsock.c

linux系统下的音频通信

    infoPtr = NewSocketInfo((SOCKET) sock);

    /*
     * Start watching for read/write events on the socket.
     */

    infoPtr->selectEvents = FD_READ | FD_CLOSE | FD_WRITE;
    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
	    SOCKET_MESSAGE, infoPtr->selectEvents);

    sprintf(channelName, "sock%d", infoPtr->socket);
    infoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
	    (ClientData) infoPtr, (TCL_READABLE | TCL_WRITABLE));
    Tcl_SetChannelOption(NULL, infoPtr->channel, "-translation", "auto crlf");
    return infoPtr->channel;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_OpenTcpServer --
 *
 *	Opens a TCP server socket and creates a channel around it.
 *
 * Results:
 *	The channel or NULL if failed.  An error message is returned
 *	in the interpreter on failure.
 *
 * Side effects:
 *	Opens a server socket and creates a new channel.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_OpenTcpServer(interp, port, host, acceptProc, acceptProcData)
    Tcl_Interp *interp;			/* For error reporting - may be
                                         * NULL. */
    int port;				/* Port number to open. */
    char *host;				/* Name of local host. */
    Tcl_TcpAcceptProc *acceptProc;	/* Callback for accepting connections
                                         * from new clients. */
    ClientData acceptProcData;		/* Data for the callback. */
{
    SocketInfo *infoPtr;
    char channelName[20];

    if (TclHasSockets(interp) != TCL_OK) {
	return NULL;
    }

    /*
     * Create a new client socket and wrap it in a channel.
     */

    infoPtr = CreateSocket(interp, port, host, 1, NULL, 0, 0);
    if (infoPtr == NULL) {
	return NULL;
    }

    infoPtr->acceptProc = acceptProc;
    infoPtr->acceptProcData = acceptProcData;

    sprintf(channelName, "sock%d", infoPtr->socket);

    infoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
	    (ClientData) infoPtr, 0);
    if (Tcl_SetChannelOption(interp, infoPtr->channel, "-eofchar", "")
	    == TCL_ERROR) {
        Tcl_Close((Tcl_Interp *) NULL, infoPtr->channel);
        return (Tcl_Channel) NULL;
    }

    return infoPtr->channel;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpAccept --
 *	Accept a TCP socket connection.  This is called by
 *	SocketEventProc and it in turns calls the registered accept
 *	procedure.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Invokes the accept proc which may invoke arbitrary Tcl code.
 *
 *----------------------------------------------------------------------
 */

static void
TcpAccept(infoPtr)
    SocketInfo *infoPtr;	/* Socket to accept. */
{
    SOCKET newSocket;
    SocketInfo *newInfoPtr;
    struct sockaddr_in addr;
    int len;
    char channelName[20];

    /*
     * Accept the incoming connection request.
     */

    len = sizeof(struct sockaddr_in);
    newSocket = (*winSock.accept)(infoPtr->socket, (struct sockaddr *)&addr,
	    &len);

    /*
     * Clear the ready mask so we can detect the next connection request.
     * Note that connection requests are level triggered, so if there is
     * a request already pending, a new event will be generated.
     */

    infoPtr->readyEvents &= ~(FD_ACCEPT);

    if (newSocket == INVALID_SOCKET) {
        return;
    }

    /*
     * Add this socket to the global list of sockets.
     */

    newInfoPtr = NewSocketInfo(newSocket);

    /*
     * Select on read/write events and create the channel.
     */

    newInfoPtr->selectEvents = (FD_READ | FD_WRITE | FD_CLOSE);
    (void) (*winSock.WSAAsyncSelect)(newInfoPtr->socket, winSock.hwnd, 
	    SOCKET_MESSAGE, newInfoPtr->selectEvents);

    sprintf(channelName, "sock%d", newInfoPtr->socket);
    newInfoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
	    (ClientData) newInfoPtr, (TCL_READABLE | TCL_WRITABLE));
    if (Tcl_SetChannelOption(NULL, newInfoPtr->channel, "-translation",
	    "auto crlf") == TCL_ERROR) {
        Tcl_Close((Tcl_Interp *) NULL, newInfoPtr->channel);
        return;
    }
    if (Tcl_SetChannelOption(NULL, newInfoPtr->channel, "-eofchar", "")
	    == TCL_ERROR) {
        Tcl_Close((Tcl_Interp *) NULL, newInfoPtr->channel);
        return;
    }

    /*
     * Invoke the accept callback procedure.
     */

    if (infoPtr->acceptProc != NULL) {
	(infoPtr->acceptProc) (infoPtr->acceptProcData, newInfoPtr->channel,
		(*winSock.inet_ntoa)(addr.sin_addr),
		(*winSock.ntohs)(addr.sin_port));
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TcpInputProc --
 *
 *	This procedure is called by the generic IO level to read data from
 *	a socket based channel.
 *
 * Results:
 *	The number of bytes read or -1 on error.
 *
 * Side effects:
 *	Consumes input from the socket.
 *
 *----------------------------------------------------------------------
 */

static int
TcpInputProc(instanceData, buf, toRead, errorCodePtr)
    ClientData instanceData;		/* The socket state. */
    char *buf;				/* Where to store data. */
    int toRead;				/* Maximum number of bytes to read. */
    int *errorCodePtr;			/* Where to store error codes. */
{
    SocketInfo *infoPtr = (SocketInfo *) instanceData;
    int bytesRead;
    int error;
    
    *errorCodePtr = 0;

    /*
     * Check that WinSock is initialized; do not call it if not, to
     * prevent system crashes. This can happen at exit time if the exit
     * handler for WinSock ran before other exit handlers that want to
     * use sockets.
     */

    if (winSock.hInstance == NULL) {
        *errorCodePtr = EFAULT;
        return -1;
    }

    /*
     * First check to see if EOF was already detected, to prevent
     * calling the socket stack after the first time EOF is detected.
     */

    if (infoPtr->flags & SOCKET_EOF) {
	return 0;
    }

    /*
     * Check to see if the socket is connected before trying to read.
     */

    if ((infoPtr->flags & SOCKET_ASYNC_CONNECT)
	    && ! WaitForSocketEvent(infoPtr,  FD_CONNECT, errorCodePtr)) {
	return -1;
    }
    
    /*
     * 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.
     */

    while (1) {
	(void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
		0, 0);
	bytesRead = (*winSock.recv)(infoPtr->socket, buf, toRead, 0);
	infoPtr->readyEvents &= ~(FD_READ);

	/*
	 * Check for end-of-file condition or successful read.
	 */

	if (bytesRead == 0) {
	    infoPtr->flags |= SOCKET_EOF;
	}
	if (bytesRead != SOCKET_ERROR) {
	    break;
	}

	/*
	 * If an error occurs after the FD_CLOSE has arrived,
	 * then ignore the error and report an EOF.
	 */

	if (infoPtr->readyEvents & FD_CLOSE) {
	    infoPtr->flags |= SOCKET_EOF;
	    bytesRead = 0;
	    break;
	}

	/*
	 * Check for error condition or underflow in non-blocking case.
	 */

	error = (*winSock.WSAGetLastError)();
	if ((infoPtr->flags & SOCKET_ASYNC) || (error != WSAEWOULDBLOCK)) {
	    TclWinConvertWSAError(error);
	    *errorCodePtr = Tcl_GetErrno();
	    bytesRead = -1;
	    break;
	}

	/*
	 * In the blocking case, wait until the file becomes readable
	 * or closed and try again.
	 */

	if (!WaitForSocketEvent(infoPtr, FD_READ|FD_CLOSE, errorCodePtr)) {
	    bytesRead = -1;
	    break;
	}
    }
    
    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
	    SOCKET_MESSAGE, infoPtr->selectEvents);
    return bytesRead;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpOutputProc --
 *
 *	This procedure is called by the generic IO level to write data
 *	to a socket based channel.
 *
 * Results:
 *	The number of bytes written or -1 on failure.
 *
 * Side effects:
 *	Produces output on the socket.
 *
 *----------------------------------------------------------------------
 */

static int
TcpOutputProc(instanceData, buf, toWrite, errorCodePtr)
    ClientData instanceData;		/* The socket state. */
    char *buf;				/* Where to get data. */
    int toWrite;			/* Maximum number of bytes to write. */
    int *errorCodePtr;			/* Where to store error codes. */
{
    SocketInfo *infoPtr = (SocketInfo *) instanceData;
    int bytesWritten;
    int error;

    *errorCodePtr = 0;

    /*
     * Check that WinSock is initialized; do not call it if not, to
     * prevent system crashes. This can happen at exit time if the exit
     * handler for WinSock ran before other exit handlers that want to
     * use sockets.
     */

    if (winSock.hInstance == NULL) {
        *errorCodePtr = EFAULT;
        return -1;
    }
    
    /*
     * Check to see if the socket is connected before trying to write.
     */
    
    if ((infoPtr->flags & SOCKET_ASYNC_CONNECT)
	    && ! WaitForSocketEvent(infoPtr,  FD_CONNECT, errorCodePtr)) {
	return -1;
    }

    while (1) {
	(void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
		0, 0);
	bytesWritten = (*winSock.send)(infoPtr->socket, buf, toWrite, 0);
	if (bytesWritten != SOCKET_ERROR) {
	    /*
	     * Since Windows won't generate a new write event until we hit
	     * an overflow condition, we need to force the event loop to
	     * poll until the condition changes.
	     */

	    if (infoPtr->watchEvents & FD_WRITE) {
		Tcl_Time blockTime = { 0, 0 };
		Tcl_SetMaxBlockTime(&blockTime);
	    }		
	    break;
	}
	
	/*
	 * 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 = (*winSock.WSAGetLastError)();
	if (error == WSAEWOULDBLOCK) {
	    infoPtr->readyEvents &= ~(FD_WRITE);
	    if (infoPtr->flags & SOCKET_ASYNC) {
		*errorCodePtr = EWOULDBLOCK;
		bytesWritten = -1;
		break;
	    } 
	} else {
	    TclWinConvertWSAError(error);
	    *errorCodePtr = Tcl_GetErrno();
	    bytesWritten = -1;
	    break;
	}

	/*
	 * In the blocking case, wait until the file becomes writable
	 * or closed and try again.
	 */

	if (!WaitForSocketEvent(infoPtr, FD_WRITE|FD_CLOSE, errorCodePtr)) {
	    bytesWritten = -1;
	    break;
	}
    }

    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
	    SOCKET_MESSAGE, infoPtr->selectEvents);
    return bytesWritten;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpGetOptionProc --
 *
 *	Computes an option value for a TCP socket based channel, or a
 *	list of all options and their values.
 *
 *	Note: This code is based on code contributed by John Haxby.
 *
 * Results:
 *	A standard Tcl result. The value of the specified option or a
 *	list of all options and	their values is returned in the
 *	supplied DString.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TcpGetOptionProc(instanceData, interp, optionName, dsPtr)
    ClientData instanceData;		/* Socket state. */
    Tcl_Interp *interp;                 /* For error reporting - can be NULL */
    char *optionName;			/* Name of the option to
                                         * retrieve the value for, or
                                         * NULL to get all options and
                                         * their values. */
    Tcl_DString *dsPtr;			/* Where to store the computed
                                         * value; initialized by caller. */
{