c# - Efficient search for generic objects without predecessors -

i have genobjectlist of generic objects , openlist of generic objects still needs used. of generic objects depend on each other. generic objects of predecessors used used. implementation use following:

var genobjectlist = // generic objects somewhere var openlist = new list<genobject>(genobjectlist); var closedlist = new list<genobject>(); var rand = new random();  while (openlist.count != 0) {                 var candidatelist =                     openlist.findall(                         t => t.predecessors.where(p => genobjectlist.contains(p)).intersect(closedlist).count() == t.predecessors.count(p => genobjectlist.contains(p)));                  var choosengenobject = candidatelist[rand.next(0, candidatelist.count)];                  openlist.remove(choosengenobject);                 closedlist.add(choosengenobject);      // generic object } 

the part find candidatelist seems inefficient if genobjectlist contains 300 entries.

i'm looking better implementation achieve same behaviour. ideas?

edit: clarify misleading use of task: question not c# tasks , methods, on generic objects have precedence constraints , how handle them. edited post make clear.

edit2: advise use topological sorting right way. i'm looking sth. described 'non deterministic topological sorting'. depth first search implementation e.g. quickgraph 1 gets same topological sorting if it's not unique. i'm looking implementation uses random number tie-breaker , has chance create topological sorting's.