/// <summary>
/// find the max latency
/// </summary>
/// <param name="sort">sorted list of vertices</param>
/// <param name="graph">delay graph</param>
/// <param name="registered">hash table of registered vertices</param>
/// <returns>number of cycles</returns>
internal static long FindMaxLatencyCore(IEnumerable <DelayGraphVertex> sort, DelayGraph graph, HashSet <DelayGraphVertex> registered)
{
long maxLatencyCost = 0;
var table = new WaveFrontDictionary <long>();
foreach (var v in sort)
{
var inEdges = graph.GetForwardInEdges(v);
var outEdges = graph.GetForwardOutEdges(v);
int myRefCount = outEdges.Count();
// first, consume predecessor's wavefront data, if any
long myCost = 0;
foreach (var e in inEdges)
{
var p = e.Source;
var c = table.Use(p); // default for long is 0
// copy data into myData
myCost = Math.Max(myCost, c);
}
// then add v's latency cost
myCost += GetLatencyCost(v, registered);
// register myCost into table
table.Define(v, myRefCount, myCost);
// update maxLatencyCost if v has no outEdges
if (myRefCount == 0 && maxLatencyCost < myCost)
{
maxLatencyCost = myCost;
}
}
return(maxLatencyCost);
}
/// <summary>
/// if myData is null, create it and register it into table using table.Define() for vertex v
/// </summary>
/// <param name="table">the wavefront dictionary</param>
/// <param name="v">a vertex</param>
/// <param name="myRefCount">reference count </param>
/// <param name="myData">original data, could be null</param>
/// <returns></returns>
private static Dictionary <DelayGraphVertex, long> GetOrMakeMyData(WaveFrontDictionary <Dictionary <DelayGraphVertex, long> > table,
DelayGraphVertex v, int myRefCount, Dictionary <DelayGraphVertex, long> myData)
{
if (myData == null)
{
myData = new Dictionary <DelayGraphVertex, long>();
table.Define(v, myRefCount, myData);
}
return(myData);
}
