/*
 * For each "vwait" event source a structure of the following type
 * is used:
 */

typedef struct {
    int *donePtr;		/* Pointer to flag to signal or NULL. */
    int sequence;		/* Order of occurrence. */
    Tcl_Size *donePtr;		/* Pointer to flag to signal or NULL. */
    Tcl_Size sequence;		/* Order of occurrence. */
    int mask;			/* 0, or TCL_READABLE/TCL_WRITABLE. */
    Tcl_Obj *sourceObj;		/* Name of the event source, either a
				 * variable name or channel name. */
} VwaitItem;

/*
 * For each exit handler created with a call to Tcl_Create(Late)ExitHandler

 *----------------------------------------------------------------------
 */

int
TclDefaultBgErrorHandlerObjCmd(
    TCL_UNUSED(void *),
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Size objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Obj *valuePtr;
    Tcl_Obj *tempObjv[2];
    int result, code, level;
    Tcl_InterpState saved;

	 * barrage of error messages. The hidden "bgerror" command can be used
	 * by a security policy to interpose on such attacks and e.g. kill the
	 * applet after a few attempts.
	 */

	if (Tcl_IsSafe(interp)) {
	    Tcl_RestoreInterpState(interp, saved);
	    Tcl_NRCallObjProc(interp, TclNRInvoke, NULL, 2, tempObjv);
	    Tcl_NRCallObjProc2(interp, TclNRInvoke, NULL, 2, tempObjv);
	} else {
	    Tcl_Channel errChannel = Tcl_GetStdChannel(TCL_STDERR);

	    if (errChannel != NULL) {
		Tcl_Obj *resultPtr = Tcl_GetObjResult(interp);

		Tcl_IncrRefCount(resultPtr);

 *----------------------------------------------------------------------
 */

int
Tcl_VwaitObjCmd(
    TCL_UNUSED(void *),
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Size objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Size i, done = 0, numItems = 0, timedOut = 0;
    int i, done = 0, timedOut = 0, foundEvent, any = 1, timeout = 0;
    int numItems = 0, extended = 0, result, mode, mask = TCL_ALL_EVENTS;
    int foundEvent, any = 1, timeout = 0;
    int extended = 0, result, mode, mask = TCL_ALL_EVENTS;
    Tcl_InterpState saved = NULL;
    Tcl_TimerToken timer = NULL;
    Tcl_Time before, after;
    Tcl_Channel chan;
    Tcl_WideInt diff = -1;
    VwaitItem localItems[32], *vwaitItems = localItems;
    static const char *const vWaitOptionStrings[] = {

	    result = Tcl_TraceVar2(interp, TclGetString(objv[i]), NULL,
		    TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		    VwaitVarProc, &vwaitItems[numItems]);
	    if (result != TCL_OK) {
		goto done;
	    }
	    vwaitItems[numItems].donePtr = &done;
	    vwaitItems[numItems].sequence = -1;
	    vwaitItems[numItems].sequence = TCL_INDEX_NONE;
	    vwaitItems[numItems].mask = 0;
	    vwaitItems[numItems].sourceObj = objv[i];
	    numItems++;
	    break;
	case OPT_READABLE:
	    if (++i >= objc) {
		goto needArg;

			TclGetString(objv[i])));
		result = TCL_ERROR;
		goto done;
	    }
	    Tcl_CreateChannelHandler(chan, TCL_READABLE,
		    VwaitChannelReadProc, &vwaitItems[numItems]);
	    vwaitItems[numItems].donePtr = &done;
	    vwaitItems[numItems].sequence = -1;
	    vwaitItems[numItems].sequence = TCL_INDEX_NONE;
	    vwaitItems[numItems].mask = TCL_READABLE;
	    vwaitItems[numItems].sourceObj = objv[i];
	    numItems++;
	    break;
	case OPT_WRITABLE:
	    if (++i >= objc) {
		goto needArg;

			TclGetString(objv[i])));
		result = TCL_ERROR;
		goto done;
	    }
	    Tcl_CreateChannelHandler(chan, TCL_WRITABLE,
		    VwaitChannelWriteProc, &vwaitItems[numItems]);
	    vwaitItems[numItems].donePtr = &done;
	    vwaitItems[numItems].sequence = -1;
	    vwaitItems[numItems].sequence = TCL_INDEX_NONE;
	    vwaitItems[numItems].mask = TCL_WRITABLE;
	    vwaitItems[numItems].sourceObj = objv[i];
	    numItems++;
	    break;
	default:
	    TCL_UNREACHABLE();
	}

	result = Tcl_TraceVar2(interp, TclGetString(objv[i]), NULL,
		TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		VwaitVarProc, &vwaitItems[numItems]);
	if (result != TCL_OK) {
	    break;
	}
	vwaitItems[numItems].donePtr = &done;
	vwaitItems[numItems].sequence = -1;
	vwaitItems[numItems].sequence = TCL_INDEX_NONE;
	vwaitItems[numItems].mask = 0;
	vwaitItems[numItems].sourceObj = objv[i];
	numItems++;
    }
    if (result != TCL_OK) {
	result = TCL_ERROR;
	goto done;

		goto done;
	    }
	}
    }

    if (timeout > 0) {
	vwaitItems[numItems].donePtr = &timedOut;
	vwaitItems[numItems].sequence = -1;
	vwaitItems[numItems].sequence = TCL_INDEX_NONE;
	vwaitItems[numItems].mask = 0;
	vwaitItems[numItems].sourceObj = NULL;
	timer = Tcl_CreateTimerHandler(timeout, VwaitTimeoutProc,
		&vwaitItems[numItems]);
	Tcl_GetTime(&before);
    } else {
	timeout = 0;

		    NULL, TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS,
		    VwaitVarProc, &vwaitItems[i]);
	}
    }

    if (result == TCL_OK) {
	if (extended) {
	    int k;
	    Tcl_Size k;
	    Tcl_Obj *listObj, *keyObj;

	    TclNewObj(listObj);
	    for (k = 0; k < done; k++) {
		for (i = 0; i < numItems; i++) {
		    if (vwaitItems[i].sequence != k) {
			continue;

 *----------------------------------------------------------------------
 */

int
Tcl_UpdateObjCmd(
    TCL_UNUSED(void *),
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Size objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    int flags = 0;		/* Initialized to avoid compiler warning. */
    static const char *const updateOptions[] = {"idletasks", NULL};
    enum updateOptionsEnum {OPT_IDLETASKS} optionIndex;

    if (objc == 1) {