tclwinsock.c

linux系统下的音频通信

}

/*
 *----------------------------------------------------------------------
 *
 * SocketExitHandler --
 *
 *	Callback invoked during exit clean up to delete the socket
 *	communication window and to release the WinSock DLL.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

    /* ARGSUSED */
static void
SocketExitHandler(clientData)
    ClientData clientData;              /* Not used. */
{
    if (winSock.hInstance) {
	DestroyWindow(winSock.hwnd);
	UnregisterClass("TclSocket", TclWinGetTclInstance());
	(*winSock.WSACleanup)();
	FreeLibrary(winSock.hInstance);
	winSock.hInstance = NULL;
    }
    Tcl_DeleteEventSource(SocketSetupProc, SocketCheckProc, NULL);
    initialized = 0;
    hostnameInitialized = 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TclHasSockets --
 *
 *	This function determines whether sockets are available on the
 *	current system and returns an error in interp if they are not.
 *	Note that interp may be NULL.
 *
 * Results:
 *	Returns TCL_OK if the system supports sockets, or TCL_ERROR with
 *	an error in interp.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
TclHasSockets(interp)
    Tcl_Interp *interp;
{
    if (!initialized) {
	InitSockets();
    }
    
    if (winSock.hInstance != NULL) {
	return TCL_OK;
    }
    if (interp != NULL) {
	Tcl_AppendResult(interp, "sockets are not available on this system",
		NULL);
    }
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * SocketSetupProc --
 *
 *	This procedure is invoked before Tcl_DoOneEvent blocks waiting
 *	for an event.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Adjusts the block time if needed.
 *
 *----------------------------------------------------------------------
 */

void
SocketSetupProc(data, flags)
    ClientData data;		/* Not used. */
    int flags;			/* Event flags as passed to Tcl_DoOneEvent. */
{
    SocketInfo *infoPtr;
    Tcl_Time blockTime = { 0, 0 };

    if (!(flags & TCL_FILE_EVENTS)) {
	return;
    }
    
    /*
     * Check to see if there is a ready socket.  If so, poll.
     */

    for (infoPtr = socketList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
	if (infoPtr->readyEvents & infoPtr->watchEvents) {
	    Tcl_SetMaxBlockTime(&blockTime);
	    break;
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * SocketCheckProc --
 *
 *	This procedure is called by Tcl_DoOneEvent to check the socket
 *	event source for events. 
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May queue an event.
 *
 *----------------------------------------------------------------------
 */

static void
SocketCheckProc(data, flags)
    ClientData data;		/* Not used. */
    int flags;			/* Event flags as passed to Tcl_DoOneEvent. */
{
    SocketInfo *infoPtr;
    SocketEvent *evPtr;

    if (!(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).
     */

    for (infoPtr = socketList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
	if ((infoPtr->readyEvents & infoPtr->watchEvents)
		&& !(infoPtr->flags & SOCKET_PENDING)) {
	    infoPtr->flags |= SOCKET_PENDING;
	    evPtr = (SocketEvent *) ckalloc(sizeof(SocketEvent));
	    evPtr->header.proc = SocketEventProc;
	    evPtr->socket = infoPtr->socket;
	    Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * SocketEventProc --
 *
 *	This procedure is called by Tcl_ServiceEvent when a socket event
 *	reaches the front of the event queue.  This procedure is
 *	responsible for notifying the generic channel code.
 *
 * Results:
 *	Returns 1 if the event was handled, meaning it should be removed
 *	from the queue.  Returns 0 if the event was not handled, meaning
 *	it should stay on the queue.  The only time the event isn't
 *	handled is if the TCL_FILE_EVENTS flag bit isn't set.
 *
 * Side effects:
 *	Whatever the channel callback procedures do.
 *
 *----------------------------------------------------------------------
 */

static int
SocketEventProc(evPtr, flags)
    Tcl_Event *evPtr;		/* Event to service. */
    int flags;			/* Flags that indicate what events to
				 * handle, such as TCL_FILE_EVENTS. */
{
    SocketInfo *infoPtr;
    SocketEvent *eventPtr = (SocketEvent *) evPtr;
    int mask = 0;
    int events;

    if (!(flags & TCL_FILE_EVENTS)) {
	return 0;
    }

    /*
     * Find the specified socket on the socket list.
     */

    for (infoPtr = socketList; infoPtr != NULL; infoPtr = infoPtr->nextPtr) {
	if (infoPtr->socket == eventPtr->socket) {
	    break;
	}
    }

    /*
     * Discard events that have gone stale.
     */

    if (!infoPtr) {
	return 1;
    }

    infoPtr->flags &= ~SOCKET_PENDING;

    /*
     * Handle connection requests directly.
     */

    if (infoPtr->readyEvents & FD_ACCEPT) {
	TcpAccept(infoPtr);
	return 1;
    }


    /*
     * Mask off unwanted events and compute the read/write mask so 
     * we can notify the channel.
     */

    events = infoPtr->readyEvents & infoPtr->watchEvents;

    if (events & FD_CLOSE) {
	/*
	 * If the socket was closed and the channel is still interested
	 * in read events, then we need to ensure that we keep polling
	 * for this event until someone does something with the channel.
	 * Note that we do this before calling Tcl_NotifyChannel so we don't
	 * have to watch out for the channel being deleted out from under
	 * us.  This may cause a redundant trip through the event loop, but
	 * it's simpler than trying to do unwind protection.
	 */

	Tcl_Time blockTime = { 0, 0 };
	Tcl_SetMaxBlockTime(&blockTime);
	mask |= TCL_READABLE;
    } else if (events & FD_READ) {
	fd_set readFds;
	struct timeval timeout;

	/*
	 * We must check to see if data is really available, since someone
	 * could have consumed the data in the meantime.  Turn off async
	 * notification so select will work correctly.  If the socket is
	 * still readable, notify the channel driver, otherwise reset the
	 * async select handler and keep waiting.
	 */

	(void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd, 0, 0);

	FD_ZERO(&readFds);
	FD_SET(infoPtr->socket, &readFds);
	timeout.tv_usec = 0;
	timeout.tv_sec = 0;

	if ((*winSock.select)(0, &readFds, NULL, NULL, &timeout) != 0) {
	    mask |= TCL_READABLE;
	} else {
	    (void) (*winSock.WSAAsyncSelect)(infoPtr->socket, winSock.hwnd,
		    SOCKET_MESSAGE, infoPtr->selectEvents);
	    infoPtr->readyEvents &= ~(FD_READ);
	}

    }
    if (events & FD_WRITE) {
	mask |= TCL_WRITABLE;
    }

    if (mask) {
	Tcl_NotifyChannel(infoPtr->channel, mask);
    }
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpBlockProc --
 *
 *	Sets a socket into blocking or non-blocking mode.
 *
 * Results:
 *	0 if successful, errno if there was an error.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TcpBlockProc(instanceData, mode)
    ClientData	instanceData;	/* The socket to block/un-block. */
    int mode;			/* TCL_MODE_BLOCKING or
                                 * TCL_MODE_NONBLOCKING. */
{
    SocketInfo *infoPtr = (SocketInfo *) instanceData;

    if (mode == TCL_MODE_NONBLOCKING) {
	infoPtr->flags |= SOCKET_ASYNC;
    } else {
	infoPtr->flags &= ~(SOCKET_ASYNC);
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpCloseProc --
 *
 *	This procedure is called by the generic IO level to perform
 *	channel type specific cleanup on a socket based channel
 *	when the channel is closed.
 *
 * Results:
 *	0 if successful, the value of errno if failed.
 *
 * Side effects:
 *	Closes the socket.
 *
 *----------------------------------------------------------------------
 */

    /* ARGSUSED */
static int
TcpCloseProc(instanceData, interp)
    ClientData instanceData;	/* The socket to close. */
    Tcl_Interp *interp;		/* Unused. */
{
    SocketInfo *infoPtr = (SocketInfo *) instanceData;
    SocketInfo **nextPtrPtr;
    int errorCode = 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) {
        
	/*
         * Clean up the OS socket handle.  The default Windows setting
	 * for a socket is SO_DONTLINGER, which does a graceful shutdown
	 * in the background.
         */
    
        if ((*winSock.closesocket)(infoPtr->socket) == SOCKET_ERROR) {
            TclWinConvertWSAError((*winSock.WSAGetLastError)());
            errorCode = Tcl_GetErrno();
        }
    }

    /*
     * Remove the socket from socketList.
     */

    for (nextPtrPtr = &socketList; (*nextPtrPtr) != NULL;
	 nextPtrPtr = &((*nextPtrPtr)->nextPtr)) {
	if ((*nextPtrPtr) == infoPtr) {
	    (*nextPtrPtr) = infoPtr->nextPtr;
	    break;
	}
    }
    ckfree((char *) infoPtr);
    return errorCode;
}

/*
 *----------------------------------------------------------------------
 *
 * NewSocketInfo --
 *
 *	This function allocates and initializes a new SocketInfo
 *	structure.
 *
 * Results:
 *	Returns a newly allocated SocketInfo.
 *
 * Side effects:
 *	Adds the socket to the global socket list.
 *
 *----------------------------------------------------------------------
 */

static SocketInfo *
NewSocketInfo(socket)
    SOCKET socket;
{
    SocketInfo *infoPtr;

    infoPtr = (SocketInfo *) ckalloc((unsigned) sizeof(SocketInfo));
    infoPtr->socket = socket;
    infoPtr->flags = 0;
    infoPtr->watchEvents = 0;
    infoPtr->readyEvents = 0;
    infoPtr->selectEvents = 0;
    infoPtr->acceptProc = NULL;
    infoPtr->lastError = 0;
    infoPtr->nextPtr = socketList;
    socketList = infoPtr;
    return infoPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * CreateSocket --
 *
 *	This function opens a new socket and initializes the
 *	SocketInfo structure.