tclmacsock.c

linux系统下的音频通信

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

    for (statePtr = socketList; statePtr != NULL;
	    statePtr = statePtr->nextPtr) {
	/*
	 * Check to see if this socket is dead and needs to be cleaned
	 * up.  We use a dummy statePtr whose only valid field is the
	 * nextPtr to allow the loop to continue even if the element
	 * is deleted.
	 */

	if (statePtr->flags & TCP_RELEASE) {
	    if (!(statePtr->flags & TCP_PENDING)) {
		dummyState.nextPtr = statePtr->nextPtr;
		SocketFreeProc(statePtr);
		statePtr = &dummyState;
	    }
	    continue;
	}

	if (!(statePtr->flags & TCP_PENDING) && SocketReady(statePtr)) {
	    statePtr->flags |= TCP_PENDING;
	    evPtr = (SocketEvent *) ckalloc(sizeof(SocketEvent));
	    evPtr->header.proc = SocketEventProc;
	    evPtr->statePtr = statePtr;
	    evPtr->tcpStream = statePtr->tcpStream;
	    Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * SocketReady --
 *
 *	This function checks the current state of a socket to see
 *	if any interesting conditions are present.
 *
 * Results:
 *	Returns 1 if an event that someone is watching is present, else
 *	returns 0.
 *
 * Side effects:
 *	Updates the checkMask for the socket to reflect any newly
 *	detected events.
 *
 *----------------------------------------------------------------------
 */

static int
SocketReady(
    TcpState *statePtr)
{
    TCPiopb statusPB;
    int foundSomething = 0;
    int didStatus = 0;
    int amount;
    OSErr err;

    if (statePtr->flags & TCP_LISTEN_CONNECT) {
	foundSomething = 1;
	statePtr->checkMask |= TCL_READABLE;
    }
    if (statePtr->watchMask & TCL_READABLE) {
	if (statePtr->checkMask & TCL_READABLE) {
	    foundSomething = 1;
	} else if (statePtr->flags & TCP_CONNECTED) {
	    statusPB.ioCRefNum = driverRefNum;
	    statusPB.tcpStream = statePtr->tcpStream;
	    statusPB.csCode = TCPStatus;
	    err = PBControlSync((ParmBlkPtr) &statusPB);
	    didStatus = 1;

	    /*
	     * We make the fchannel readable if 1) we get an error,
	     * 2) there is more data available, or 3) we detect
	     * that a close from the remote connection has arrived.
	     */

	    if ((err != noErr) ||
		    (statusPB.csParam.status.amtUnreadData > 0) ||
		    (statusPB.csParam.status.connectionState == 14)) {
		statePtr->checkMask |= TCL_READABLE;
		foundSomething = 1;
	    }
	}
    }
    if (statePtr->watchMask & TCL_WRITABLE) {
	if (statePtr->checkMask & TCL_WRITABLE) {
	    foundSomething = 1;
	} else if (statePtr->flags & TCP_CONNECTED) {
	    if (!didStatus) {
		statusPB.ioCRefNum = driverRefNum;
		statusPB.tcpStream = statePtr->tcpStream;
		statusPB.csCode = TCPStatus;
		err = PBControlSync((ParmBlkPtr) &statusPB);
	    }

	    /*
	     * If there is an error or there if there is room to
	     * send more data we make the channel writeable.
	     */

	    amount = statusPB.csParam.status.sendWindow - 
		statusPB.csParam.status.amtUnackedData;
	    if ((err != noErr) || (amount > 0)) {
		statePtr->checkMask |= TCL_WRITABLE;
		foundSomething = 1;
	    }
	}
    }
    return foundSomething;
}

/*
 *----------------------------------------------------------------------
 *
 * InitMacTCPParamBlock--
 *
 *	Initialize a MacTCP parameter block.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Initializes the parameter block.
 *
 *----------------------------------------------------------------------
 */

static void
InitMacTCPParamBlock(
    TCPiopb *pBlock,		/* Tcp parmeter block. */
    int csCode)			/* Tcp operation code. */
{
    memset(pBlock, 0, sizeof(TCPiopb));
    pBlock->ioResult = 1;
    pBlock->ioCRefNum = driverRefNum;
    pBlock->csCode = (short) csCode;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpBlockMode --
 *
 *	Set blocking or non-blocking mode on channel.
 *
 * Results:
 *	0 if successful, errno when failed.
 *
 * Side effects:
 *	Sets the device into blocking or non-blocking mode.
 *
 *----------------------------------------------------------------------
 */

static int
TcpBlockMode(
    ClientData instanceData, 		/* Channel state. */
    int mode)				/* The mode to set. */
{
    TcpState *statePtr = (TcpState *) instanceData;
    
    if (mode == TCL_MODE_BLOCKING) {
	statePtr->flags &= ~TCP_ASYNC_SOCKET;
    } else {
	statePtr->flags |= TCP_ASYNC_SOCKET;
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpClose --
 *
 *	Close the socket.
 *
 * Results:
 *	0 if successful, the value of errno if failed.
 *
 * Side effects:
 *	Closes the socket.
 *
 *----------------------------------------------------------------------
 */

static int
TcpClose(
    ClientData instanceData,		/* The socket to close. */
    Tcl_Interp *interp)			/* Interp for error messages. */
{
    TcpState *statePtr = (TcpState *) instanceData;
    StreamPtr tcpStream;
    TCPiopb closePB;
    OSErr err;

    tcpStream = statePtr->tcpStream;
    statePtr->flags &= ~TCP_CONNECTED;
    
    /*
     * If this is a server socket we can't use the statePtr
     * param block because it is in use.  However, we can 
     * close syncronously.
     */

    if ((statePtr->flags & TCP_LISTENING) ||
	    (statePtr->flags & TCP_LISTEN_CONNECT)) {
	InitMacTCPParamBlock(&closePB, TCPClose);
    	closePB.tcpStream = tcpStream;
    	closePB.ioCompletion = NULL; 
    	err = PBControlSync((ParmBlkPtr) &closePB);
    	if (err != noErr) {
    	    Debugger();
            panic("error closing server socket");
    	}
	statePtr->flags |= TCP_RELEASE;

	/*
	 * Server sockets are closed sync.  Therefor, we know it is OK to
	 * release the socket now.
	 */

	InitMacTCPParamBlock(&statePtr->pb, TCPRelease);
	statePtr->pb.tcpStream = statePtr->tcpStream;
	err = PBControlSync((ParmBlkPtr) &statePtr->pb);
	if (err != noErr) {
            panic("error releasing server socket");
	}

	/*
	 * Free the buffer space used by the socket and the 
	 * actual socket state data structure.
	 */

	ckfree((char *) statePtr->pb.csParam.create.rcvBuff);
	FreeSocketInfo(statePtr);
	return 0;
    }

    /*
     * If this socket is in the midddle on async connect we can just
     * abort the connect and release the stream right now.
     */
 
    if (statePtr->flags & TCP_ASYNC_CONNECT) {
	InitMacTCPParamBlock(&closePB, TCPClose);
    	closePB.tcpStream = tcpStream;
    	closePB.ioCompletion = NULL; 
    	err = PBControlSync((ParmBlkPtr) &closePB);
    	if (err != noErr) {
            panic("error closing async connect socket");
    	}
	statePtr->flags |= TCP_RELEASE;

	InitMacTCPParamBlock(&statePtr->pb, TCPRelease);
	statePtr->pb.tcpStream = statePtr->tcpStream;
	err = PBControlSync((ParmBlkPtr) &statePtr->pb);
	if (err != noErr) {
            panic("error releasing async connect socket");
	}

	/*
	 * Free the buffer space used by the socket and the 
	 * actual socket state data structure.
	 */

	ckfree((char *) statePtr->pb.csParam.create.rcvBuff);
	FreeSocketInfo(statePtr);
	return 0;
    }

    /*
     * Client sockets:
     * If a background write is in progress, don't close
     * the socket yet.  The completion routine for the 
     * write will take care of it.
     */
    
    if (!(statePtr->flags & TCP_WRITING)) {
	InitMacTCPParamBlock(&statePtr->pb, TCPClose);
    	statePtr->pb.tcpStream = tcpStream;
    	statePtr->pb.ioCompletion = closeUPP; 
    	statePtr->pb.csParam.close.userDataPtr = (Ptr) statePtr;
    	err = PBControlAsync((ParmBlkPtr) &statePtr->pb);
    	if (err != noErr) {
	    Debugger();
	    statePtr->flags |= TCP_RELEASE;
            /* return 0; */
    	}
    }

    SocketFreeProc(instanceData);
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * CloseCompletionRoutine --
 *
 *	Handles the close protocol for a Tcp socket.  This will do
 *	a series of calls to release all data currently buffered for
 *	the socket.  This is important to do to as it allows the remote
 *	connection to recieve and issue it's own close on the socket.
 *	Note that this function is running at interupt time and can't
 *	allocate memory or do much else except set state.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The buffers for the socket are flushed.
 *
 *----------------------------------------------------------------------
 */

static void
CloseCompletionRoutine(
    TCPiopb *pbPtr)		/* Tcp parameter block. */
{
    TcpState *statePtr;
    OSErr err;
    
    if (pbPtr->csCode == TCPClose) {
	statePtr = (TcpState *) (pbPtr->csParam.close.userDataPtr);
    } else {
	statePtr = (TcpState *) (pbPtr->csParam.receive.userDataPtr);
    }

    /*
     * It's very bad if the statePtr is nNULL - we should probably panic...
     */

    if (statePtr == NULL) {
	Debugger();
	return;
    }
    
    WakeUpProcess(&statePtr->psn);

    /*
     * If there is an error we assume the remote side has already
     * close.  We are done closing as soon as we decide that the
     * remote connection has closed.
     */
    
    if (pbPtr->ioResult != noErr) {
	statePtr->flags |= TCP_RELEASE;
	return;
    }
    if (statePtr->flags & TCP_REMOTE_CLOSED) {
	statePtr->flags |= TCP_RELEASE;
	return;
    }
    
    /*
     * If we just did a recieve we need to return the buffers.
     * Otherwise, attempt to recieve more data until we recieve an
     * error (usually because we have no more data).
     */

    if (statePtr->pb.csCode == TCPNoCopyRcv) {
	InitMacTCPParamBlock(&statePtr->pb, TCPRcvBfrReturn);
    	statePtr->pb.tcpStream = statePtr->tcpStream;
	statePtr->pb.ioCompletion = closeUPP; 
	statePtr->pb.csParam.receive.rdsPtr = (Ptr) statePtr->rdsarray;
    	statePtr->pb.csParam.receive.userDataPtr = (Ptr) statePtr;
	err = PBControlAsync((ParmBlkPtr) &statePtr->pb);
    } else {
	InitMacTCPParamBlock(&statePtr->pb, TCPNoCopyRcv);
    	statePtr->pb.tcpStream = statePtr->tcpStream;
	statePtr->pb.ioCompletion = closeUPP; 
	statePtr->pb.csParam.receive.commandTimeoutValue = 1;
	statePtr->pb.csParam.receive.rdsPtr = (Ptr) statePtr->rdsarray;
	statePtr->pb.csParam.receive.rdsLength = 5;
    	statePtr->pb.csParam.receive.userDataPtr = (Ptr) statePtr;
	err = PBControlAsync((ParmBlkPtr) &statePtr->pb);
    }

    if (err != noErr) {
	statePtr->flags |= TCP_RELEASE;
    }
}
/*
 *----------------------------------------------------------------------
 *
 * SocketFreeProc --
 *
 *      This callback is invoked in order to delete
 *      the notifier data associated with a file handle.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Removes the SocketInfo from the global socket list.
 *
 *----------------------------------------------------------------------
 */

static void
SocketFreeProc(
    ClientData clientData)      /* Channel state. */
{
    TcpState *statePtr = (TcpState *) clientData;
    OSErr err;
    TCPiopb statusPB;

    /*
     * Get the status of this connection.  We need to do a
     * few tests to see if it's OK to release the stream now.
     */

    if (!(statePtr->flags & TCP_RELEASE)) {
	return;
    }
    statusPB.ioCRefNum = driverRefNum;
    statusPB.tcpStream = statePtr->tcpStream;
    statusPB.csCode = TCPStatus;
    err = PBControlSync((ParmBlkPtr) &statusPB);
    if ((statusPB.csParam.status.connectionState == 0) ||
	(statusPB.csParam.status.connectionState == 2)) {
	/*
	 * If the conection state is 0 then this was a client
	 * connection and it's closed.  If it is 2 then this a
	 * server client and we may release it.  If it isn't
	 * one of those values then we return and we'll try to
	 * clean up later.
	 */

    } else {
	return;
    }
    
    /*
     * The Close request is made async.  We know it's
     * OK to release the socket when the TCP_RELEASE flag
     * gets set.
     */

    InitMacTCPParamBlock(&statePtr->pb, TCPRelease);
    statePtr->pb.tcpStream = statePtr->tcpStream;
    err = PBControlSync((ParmBlkPtr) &statePtr->pb);
    if (err != noErr) {
        Debugger(); /* Ignoreing leaves stranded stream.  Is there an
		       alternative?  */
    }

    /*
     * Free the buffer space used by the socket and the 
     * actual socket state data structure.
     */

    ckfree((char *) statePtr->pb.csParam.create.rcvBuff);
    FreeSocketInfo(statePtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TcpInput --
 *
 *	Reads input from the IO channel into the buffer given. Returns
 *	count of how many bytes were actually read, and an error 
 *	indication.
 *
 * Results:
 *	A count of how many bytes were read is returned.  A value of -1
 *	implies an error occured.  A value of zero means we have reached
 *	the end of data (EOF).
 *
 * Side effects:
 *	Reads input from the actual channel.
 *
 *----------------------------------------------------------------------
 */

int
TcpInput(
    ClientData instanceData,		/* Channel state. */