############################################################################## This code was developed as part of the MIT SPIN project. (jk, wbh 3/24/00)############################################################################## ResourceManager Class## This is an abstract super class of resource manager. The functions Query,# Request and Update are virtual.Class ResourceManagerResourceManager instproc init {args} {    eval $self next $args    $self instvar arrayOfResources_ arrayOfOperation_    set arrayOfResources_ {}    set arrayOfOperation_ {}}ResourceManager instproc getResourceByType resourceType {    $self instvar arrayOfResources_    # go through each element of the resource array, find the matched type    foreach obj $arrayOfResources_ {        if { [$obj info class] == $resourceType } {            return $obj        }    }    return {}}ResourceManager instproc Register resourceObj {    $self instvar arrayOfResources_    # check if this type of resource have been registered before. Currently    # the resource manager only register non-duplicate type of resources.    set r [$resourceObj info class]    if { [$self getResourceByType $r] != {} } {        puts "This type of resource ( $r ) have been registered in resource manager before."        return -1    }    # add this object to resource list    lappend arrayOfResources_ $resourceObj    return 1}# The Query function return a list of resource objects, which match the input# resource types given by argsResourceManager instproc Query {args} {    $self instvar arrayOfResources_    # if want to fetch all the resource objects    if { [lsearch $args all] != -1 } {      return $arrayOfResources_    }    # for each resource type in the args, get the corresponding resource in     # the resource array, and append to the return list     set ret {}    foreach rsType $args {      if { [set obj [$self getResourceByType $rsType]] != {} } {        lappend ret $obj      }    }    return $ret}ResourceManager instproc Request {args} {    puts stderr "Warning: Request function not implemented yet for this object"}ResourceManager instproc Update {args} {    puts stderr "Warning: Update function not implemented yet for this object"}