/* 
 * tclLoad.c --
 *
 *	This file provides the generic portion (those that are the same
 *	on all platforms) of Tcl's dynamic loading facilities.
 *
 * Copyright (c) 1995-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclLoad.c,v 1.8 2002/07/22 16:51:48 vincentdarley Exp $
 * RCS: @(#) $Id: tclLoad.c,v 1.9 2003/02/01 23:37:29 kennykb Exp $
 */

#include "tclInt.h"

/*
 * The following structure describes a package that has been loaded
 * either dynamically (with the "load" command) or statically (as

					 * interpreters. */
{
    LoadedPackage *pkgPtr;
    InterpPackage *ipPtr, *ipFirstPtr;

    /*
     * Check to see if someone else has already reported this package as
     * statically loaded.  If this call is redundant then just return.
     * statically loaded in the process.
     */

    Tcl_MutexLock(&packageMutex);
    for (pkgPtr = firstPackagePtr; pkgPtr != NULL; pkgPtr = pkgPtr->nextPtr) {
	if ((pkgPtr->initProc == initProc)
		&& (pkgPtr->safeInitProc == safeInitProc)
		&& (strcmp(pkgPtr->packageName, pkgName) == 0)) {
	    Tcl_MutexUnlock(&packageMutex);
	    return;
	    break;
	}
    }
    Tcl_MutexUnlock(&packageMutex);

    /*
    Tcl_MutexUnlock(&packageMutex);
     * If the package is not yet recorded as being loaded statically,
     * add it to the list now.
     */

    if ( pkgPtr == NULL ) {
    pkgPtr = (LoadedPackage *) ckalloc(sizeof(LoadedPackage));
    pkgPtr->fileName		= (char *) ckalloc((unsigned) 1);
    pkgPtr->fileName[0]		= 0;
    pkgPtr->packageName		= (char *) ckalloc((unsigned)
	    (strlen(pkgName) + 1));
    strcpy(pkgPtr->packageName, pkgName);
    pkgPtr->loadHandle		= NULL;
    pkgPtr->initProc		= initProc;
    pkgPtr->safeInitProc	= safeInitProc;
    Tcl_MutexLock(&packageMutex);
    pkgPtr->nextPtr		= firstPackagePtr;
    firstPackagePtr		= pkgPtr;
    Tcl_MutexUnlock(&packageMutex);

	pkgPtr = (LoadedPackage *) ckalloc(sizeof(LoadedPackage));
	pkgPtr->fileName	= (char *) ckalloc((unsigned) 1);
	pkgPtr->fileName[0]	= 0;
	pkgPtr->packageName	= (char *) ckalloc((unsigned)
						   (strlen(pkgName) + 1));
	strcpy(pkgPtr->packageName, pkgName);
	pkgPtr->loadHandle	= NULL;
	pkgPtr->initProc	= initProc;
	pkgPtr->safeInitProc	= safeInitProc;
	Tcl_MutexLock(&packageMutex);
	pkgPtr->nextPtr		= firstPackagePtr;
	firstPackagePtr		= pkgPtr;
	Tcl_MutexUnlock(&packageMutex);
    }

    if (interp != NULL) {

	/*
	 * If we're loading the package into an interpreter,
	 * determine whether it's already loaded. 
	 */

	ipFirstPtr = (InterpPackage *) Tcl_GetAssocData(interp, "tclLoad",
		(Tcl_InterpDeleteProc **) NULL);
	for ( ipPtr = ipFirstPtr; ipPtr != NULL; ipPtr = ipPtr->nextPtr ) {
	    if ( ipPtr->pkgPtr == pkgPtr ) {
		return;
	    }
	}

	/*
	 * Package isn't loade in the current interp yet. Mark it as
	 * now being loaded.
	 */

	ipPtr = (InterpPackage *) ckalloc(sizeof(InterpPackage));
	ipPtr->pkgPtr = pkgPtr;
	ipPtr->nextPtr = ipFirstPtr;
	Tcl_SetAssocData(interp, "tclLoad", LoadCleanupProc,
		(ClientData) ipPtr);
    }
}