Lists, Stacks, and Queues - Data Structures and Algorithm Analysis - page 109

/ ** Singlylinkedlistnodewithfreelistsupport * /
classLink<E>{
privateEelement; //Valueforthisnode
privateLink<E>next;//Pointtonextnodeinlist

/ ** Constructors * /
Link(Eit,Link<E>nextval)
{element=it;next=nextval;}
Link(Link<E>nextval){next=nextval;}

/ ** Getandsetmethods * /
Link<E>next(){returnnext;}
Link<E>setNext(Link<E>nxtval){returnnext=nxtval;}
Eelement(){returnelement;}
EsetElement(Eit){returnelement=it;}

/ ** Extensionstosupportfreelists * /
staticLinkfreelist=null; //Freelistfortheclass

/ ** @returnAnewlink * /
static<E>Link<E>get(Eit,Link<E>nextval){
if(freelist==null)
returnnewLink<E>(it,nextval);//Getfrom"new"
Link<E>temp=freelist; //Getfromfreelist
freelist=freelist.next();
temp.setElement(it);
temp.setNext(nextval);
returntemp;

}

/ ** Returnalinktothefreelist * /
voidrelease(){
element=null; //Dropreferencetotheelement
next=freelist;
freelist=this;

}

}

Figure4.11 Implementation for the Link class with a freelist. The static
declaration for member freelist means that all Link class objects share the
same freelist pointer variable instead of each object storing its own copy.