we can clean up properly.****************************************************************************/static void exitHandler(int sig){    exit(-1);}/****************************************************************************REMARKS:Sleep until the virtual terminal is active****************************************************************************/void wait_vt_active(void){    while (ioctl(tty_fd, VT_WAITACTIVE, tty_vc) < 0) {        if ((errno != EAGAIN) && (errno != EINTR)) {            perror("ioctl(VT_WAITACTIVE)");            exit(1);            }        usleep(150000);        }}/****************************************************************************REMARKS:Signal handler called when our virtual terminal has been released and we arelosing the active focus.****************************************************************************/static void release_vt_signal(int n){    forbid_vt_acquire = 1;    if (forbid_vt_release) {        forbid_vt_acquire = 0;        ioctl(tty_fd, VT_RELDISP, 0);        return;        }    // TODO: Call the user supplied suspendAppCallback and restore text    //       mode (saving the existing mode so we can restore it).    //    //       Also if the suspendAppCallback is NULL then we have to    //       ignore the switch request!    if(suspendAppCallback){      oldmode = VBE_getVideoMode();      suspendAppCallback(true);      VBE_setVideoMode(initmode);    }    ioctl(tty_fd, VT_RELDISP, 1);    forbid_vt_acquire = 0;    wait_vt_active();}/****************************************************************************REMARKS:Signal handler called when our virtual terminal has been re-aquired and weare now regaiing the active focus.****************************************************************************/static void acquire_vt_signal(int n){    forbid_vt_release = 1;    if (forbid_vt_acquire) {        forbid_vt_release = 0;        return;        }    // TODO: Restore the old display mode, call the user suspendAppCallback    //       and and we will be back in graphics mode.    if(suspendAppCallback){      VBE_setVideoMode(oldmode);      suspendAppCallback(false);    }    ioctl(tty_fd, VT_RELDISP, VT_ACKACQ);    forbid_vt_release = 0;}/****************************************************************************REMARKS:Function to set the action for a specific signal to call our signal handler.****************************************************************************/static void set_sigaction(int sig,void (*handler)(int)){    struct sigaction    siga;    siga.sa_handler = handler;    siga.sa_flags = SA_RESTART;    memset(&(siga.sa_mask), 0, sizeof(sigset_t));    sigaction(sig, &siga, NULL);}/****************************************************************************REMARKS:Function to take over control of VT switching so that we can capturevirtual terminal release and aquire signals, allowing us to properlysupport VT switching while in graphics modes.****************************************************************************/static void take_vt_control(void){    struct vt_mode      vtmode;    ioctl(tty_fd, VT_GETMODE, &vtmode);    oldvtmode = vtmode;    vtmode.mode = VT_PROCESS;    vtmode.relsig = SIGUSR1;    vtmode.acqsig = SIGUSR2;    set_sigaction(SIGUSR1, release_vt_signal);    set_sigaction(SIGUSR2, acquire_vt_signal);    ioctl(tty_fd, VT_SETMODE, &oldvtmode);}/****************************************************************************REMARKS:Set the shift keyboard LED's based on the current keyboard modifiers flags.****************************************************************************/static void updateLEDStatus(void){    int state = 0;    if (key_modifiers & EVT_CAPSSTATE)        state |= LED_CAP;    if (key_modifiers & EVT_NUMSTATE)        state |= LED_NUM;    ioctl(tty_fd,KDSETLED,state);}/****************************************************************************PARAMETERS:scancode    - Raw scan code to handleREMARKS:Handles the shift key modifiers and keeps track of the shift key statesso that we can return the correct ASCII codes for the keyboard.****************************************************************************/static void toggleModifiers(    int scancode){    static int caps_down = 0,num_down = 0;    if (scancode & 0x80) {        /* Handle key-release function */        scancode &= 0x7F;        if (scancode == 0x2A || scancode == 0x36)            key_modifiers &= ~EVT_SHIFTKEY;        else if (scancode == 0x1D || scancode == 0x61)            key_modifiers &= ~EVT_CTRLSTATE;        else if (scancode == 0x38 || scancode == 0x64)            key_modifiers &= ~EVT_ALTSTATE;        else if (scancode == 0x3A)            caps_down = false;        else if (scancode == 0x45)            num_down = false;        }    else {        /* Handle key-down function */        scancode &= 0x7F;        if (scancode == 0x2A || scancode == 0x36)            key_modifiers |= EVT_SHIFTKEY;        else if (scancode == 0x1D || scancode == 0x61)            key_modifiers |= EVT_CTRLSTATE;        else if (scancode == 0x38 || scancode == 0x64)            key_modifiers |= EVT_ALTSTATE;        else if (scancode == 0x3A) {            if (!caps_down) {                key_modifiers ^= EVT_CAPSSTATE;                updateLEDStatus();                }            caps_down = true;            }        else if (scancode == 0x45) {            if (!num_down) {                key_modifiers ^= EVT_NUMSTATE;                updateLEDStatus();                }            num_down = true;            }        }}/***************************************************************************REMARKS:Returns the number of bits that have changed from 0 to 1(a negative value means the number of bits that have changed from 1 to 0)  **************************************************************************/static int compareBits(short a, short b){    int ret = 0;    if( (a&1) != (b&1) ) ret += (b&1) ? 1 : -1;    if( (a&2) != (b&2) ) ret += (b&2) ? 1 : -1;    if( (a&4) != (b&4) ) ret += (b&4) ? 1 : -1;    return ret;}/***************************************************************************REMARKS:Turns off all keyboard state because we can't rely on them anymore as soonas we switch VT's***************************************************************************/static void keyboard_clearstate(void){  key_modifiers = 0;  memset(key_down, 0, sizeof(key_down));}/****************************************************************************REMARKS:Pumps all events from the console event queue into the WinDirect event queue.****************************************************************************/static void pumpEvents(void){    static uchar    buf[KBDREADBUFFERSIZE];    static char     data[5];    static int      old_buts, old_mx, old_my;    static struct timeval t;    fd_set fds;    int             numkeys,i;    int             dx, dy, buts;    /* Read all pending keypresses from keyboard buffer and process */    while ((numkeys = read(tty_fd, buf, KBDREADBUFFERSIZE)) > 0) {        for (i = 0; i < numkeys; i++) {            toggleModifiers(buf[i]);            if (key_modifiers & EVT_ALTSTATE){              int fkey = 0;              // Do VT switching here for Alt+Fx keypresses              switch(buf[i] & 0x7F){              case 59 ... 68: /* F1 to F10 */                fkey = (buf[i] & 0x7F) - 58;                break;              case 87: /* F11 */              case 88: /* F12 */                fkey = (buf[i] & 0x7F) - 76;                break;              }              if(fkey){                struct vt_stat vts;                ioctl(tty_fd, VT_GETSTATE, &vts);                                if(fkey != vts.v_active){                  keyboard_clearstate();                  ioctl(tty_fd, VT_ACTIVATE, fkey);                }              }            }            if (buf[i] & 0x80)                addKeyEvent(EVT_KEYUP,buf[i] & 0x7F);            else                addKeyEvent(EVT_KEYDOWN,buf[i] & 0x7F);            }        // TODO: If we want to handle VC switching we will need to do it        //       in here so that we can switch away from the VC and then        //       switch back to it later. Right now VC switching is disabled        //       and in order to enable it we need to save/restore the state        //       of the graphics screen (using the suspendAppCallback and        //       saving/restoring the state of the current display mode).        }    /* Read all pending mouse events and process them */    if(conn > 0){        FD_ZERO(&fds);        FD_SET(conn, &fds);        t.tv_sec = t.tv_usec = 0L;        while (select(conn+1, &fds, NULL, NULL, &t) > 0) {            if(read(conn, data, 5) == 5){                buts = (~data[0]) & 0x07;                dx = (char)(data[1]) + (char)(data[3]);                dy = -((char)(data[2]) + (char)(data[4]));                                mx += dx; my += dy;                                if (dx || dy)                    addMouseEvent(EVT_MOUSEMOVE, 0, mx, my, buts);                                if (buts != old_buts){                    int c = compareBits(buts,old_buts);                    if(c>0)                        addMouseEvent(EVT_MOUSEDOWN, 0, mx, my, buts);                    else if(c<0)                        addMouseEvent(EVT_MOUSEUP, 0, mx, my, buts);                }                old_mx = mx; old_my = my;                old_buts = buts;                FD_SET(conn, &fds);                t.tv_sec = t.tv_usec = 0L;            }        }    }}/*------------------------ Public interface routines ----------------------*//****************************************************************************PARAMETERS:which       - Which code for event to postwhat        - Event code for event to postmessage     - Event messagemodifiers   - Shift key/mouse button modifiersRETURNS:True if the event was posted, false if queue is full.REMARKS:Posts an event to the event queue. This routine can be used to post any typeof event into the queue.****************************************************************************/ibool _WDAPI WD_postEvent(    ulong which,    uint what,    ulong message,    ulong modifiers){    WD_event    evt;    if (count < EVENTQSIZE) {        /* Save information in event record */        evt.which = which;        evt.what = what;        evt.when = getTimeStamp();        evt.message = message;        evt.modifiers = modifiers;        addEvent(&evt);             /* Add to tail of event queue   */        return true;        }    else        return false;}/****************************************************************************PARAMETERS:mask    - Event mask to useREMARKS:Flushes all the event specified in 'mask' from the event queue.****************************************************************************/void _WDAPI WD_flushEvent(    uint mask){    WD_event    evt;    do {                            /* Flush all events */        WD_getEvent(&evt,mask);        } while (evt.what != EVT_NULLEVT);}/****************************************************************************PARAMETERS:evt     - Place to store eventmask    - Event mask to useREMARKS: