/* 
 * tclTrace.c --
 *
 *	This file contains code to handle most trace management.
 *
 * Copyright (c) 1987-1993 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 * Copyright (c) 1998-2000 Scriptics Corporation.
 * Copyright (c) 2002 ActiveState Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclTrace.c,v 1.17 2004/10/19 21:54:07 dgp Exp $
 * RCS: @(#) $Id: tclTrace.c,v 1.18 2004/10/25 01:06:51 msofer Exp $
 */

#include "tclInt.h"

/*
 * Structure used to hold information about variable traces:
 */

    TclInterpState state = NULL;

    /*
     * If there are already similar trace procedures active for the
     * variable, don't call them again.
     */

    if (varPtr->flags & VAR_TRACE_ACTIVE) {
    if (TclIsVarTraceActive(varPtr)) {
	return code;
    }
    varPtr->flags |= VAR_TRACE_ACTIVE;
    TclSetVarTraceActive(varPtr);
    varPtr->refCount++;
    if (arrayPtr != NULL) {
	arrayPtr->refCount++;
    }

    /*
     * If the variable name hasn't been parsed into array name and

     * Invoke traces on the array containing the variable, if relevant.
     */

    result = NULL;
    active.nextPtr = iPtr->activeVarTracePtr;
    iPtr->activeVarTracePtr = &active;
    Tcl_Preserve((ClientData) iPtr);
    if (arrayPtr != NULL && !(arrayPtr->flags & VAR_TRACE_ACTIVE)) {
    if (arrayPtr != NULL && !TclIsVarTraceActive(arrayPtr)) {
	active.varPtr = arrayPtr;
	for (tracePtr = arrayPtr->tracePtr;  tracePtr != NULL;
	     tracePtr = active.nextTracePtr) {
	    active.nextTracePtr = tracePtr->nextPtr;
	    if (!(tracePtr->flags & flags)) {
		continue;
	    }

    if (arrayPtr != NULL) {
	arrayPtr->refCount--;
    }
    if (copiedName) {
	Tcl_DStringFree(&nameCopy);
    }
    varPtr->flags &= ~VAR_TRACE_ACTIVE;
    TclClearVarTraceActive(varPtr);
    varPtr->refCount--;
    iPtr->activeVarTracePtr = active.nextPtr;
    Tcl_Release((ClientData) iPtr);
    return code;
}

/*