Boolean FTT1pnode::go(void){
FTT1pSubnode *sub=(FTT1pSubnode*)itsSubnodes->NthItem(currentNode);
if(!sub){
nodeErr(32);
}
Boolean returnVal=TRUE,advanceToNextNode=FALSE;
#ifdef Frank_GenuineMac
TRY{
#endif
if(!sub->run()){
advanceToNextNode=TRUE;
if(!sub->func){
// the subnode has terminated voluntarily
if(newPres){
// the fat lady is singing!
// ownership of newPres passes
// to the driver and the distinguished
// subnode is removed from the list.
// Control passes to the driver.
newPresDispose=FALSE;
removeSubnode();
returnVal=FALSE;
}
else{
// the distinguished relator is not a consequence
// this can only be positively determined if the group
// generated by the other relators is finite. The node
// is removed from this list. Control passes to driver
// if there are no nodes on the list.
returnVal=removeSubnode();
}
}
}
#ifdef Frank_GenuineMac
}
CATCH{
if(gLastError==memFullErr){
NO_PROPAGATE;
// The subnode has run out of memory. If no other subnodes
// are suspended, then the subnode failed while using all
// available memory. In this case, the node is removed
// and the the algorithm is compromised.
// If there are other active subnodes, then the subnode is
// disposed and reinitialized and the list of subnodes
// is updated. This frees up memory for the remaining active
// subnodes and gives the current subnode a chance to run
// again at a future date and perhaps have better luck.
long num=itsSubnodes->numItems;
Boolean otherNodeSuspended=FALSE;
for(long i=1;i<=num && !otherNodeSuspended; ++i){
FTT1pSubnode *aSubnode;
aSubnode=(FTT1pSubnode*)itsSubnodes->NthItem(i);
if(i!=currentNode){
otherNodeSuspended= aSubnode->func!=0;
}
}
if(otherNodeSuspended){
long distinguishedRel=sub->distinguishedRel;
delete sub;sub=0;
sub= new FTT1pSubnode(this,currentPres,distinguishedRel,timeLimit);
itsSubnodes->SetItem(&sub,currentNode);
}
else{
returnVal=removeSubnode();
}
}
}
ENDTRY;
#endif
if(advanceToNextNode){
++currentNode;
if(currentNode>itsSubnodes->numItems) currentNode=1;
}
return returnVal;
}