public void TestRouteParallelSpeed()
{
var cities = new Cities();
cities.ReadCities("citiesTestDataLab12.txt");
var routes = new Routes(cities);
routes.ReadRoutes("linksTestDataLab12.txt");
//warmup
routes.FindAllShortestRoutesParallel();
//execute and measure time
var timeA = DateTime.Now;
List<List<Link>> allRoutesSerial = routes.FindAllShortestRoutes();
var timeB = DateTime.Now;
List<List<Link>> allRoutesParallel = routes.FindAllShortestRoutesParallel();
var timeC = DateTime.Now;
var oldAffinity = Process.GetCurrentProcess().ProcessorAffinity;
Process.GetCurrentProcess().ProcessorAffinity = (IntPtr)1;
routes.FindAllShortestRoutesParallel();
Process.GetCurrentProcess().ProcessorAffinity = oldAffinity;
var timeD = DateTime.Now;
var factor = (timeC - timeB).TotalSeconds / (timeB - timeA).TotalSeconds;
var slowdown = (timeD - timeC).TotalSeconds / (timeB - timeA).TotalSeconds;
Trace.WriteLine($"Factor: {factor:F2}, Slowdown: {slowdown:F2}");
//parallel execution on a single core shouldn't be much slower
Assert.IsTrue(slowdown < 1.1);
switch (Environment.ProcessorCount)
{
case 1:
break;
case 2:
//expect at least 25% reduction with 2 cores
Assert.IsTrue(factor < 0.75);
break;
case 3:
//expect at least 35% reduction with 3 cores
Assert.IsTrue(factor < 0.65);
break;
default:
//expect at least 45% reduction with 4+ cores
Assert.IsTrue(factor < 0.55);
break;
}
}
private void TestRouteParallelCorrectness(string _suffix,int _cities,int _routes,int _resultsA,int _resultsB,int _resultsC)
{
var cities = new Cities();
cities.ReadCities("citiesTestDataLab"+_suffix+".txt");
Assert.AreEqual(_cities, cities.Count);
var routes = new Routes(cities);
int count = routes.ReadRoutes("linksTestDataLab"+_suffix+".txt");
Assert.AreEqual(_routes, count);
List<List<Link>> allRoutesSerial = routes.FindAllShortestRoutes();
List<List<Link>> allRoutesParallel = routes.FindAllShortestRoutesParallel();
//should return all combinations of routes (cities * routes * TransportModes)
Assert.AreEqual(_resultsA, allRoutesSerial.Count());
Assert.AreEqual(_resultsA, allRoutesParallel.Count());
//filter out non-existing routes
allRoutesSerial = allRoutesSerial.Where(r => r != null).ToList();
allRoutesParallel = allRoutesParallel.Where(r => r != null).ToList();
//should've found a subset of valid routes
Assert.AreEqual(_resultsB, allRoutesSerial.Count());
Assert.AreEqual(_resultsB, allRoutesParallel.Count());
//filter out zero-length routes
allRoutesSerial = allRoutesSerial.Where(r => r.Count()>0).ToList();
allRoutesParallel = allRoutesParallel.Where(r => r.Count()>0).ToList();
//should've found a subset of non-zero-length routes
Assert.AreEqual(_resultsC, allRoutesSerial.Count());
Assert.AreEqual(_resultsC, allRoutesParallel.Count());
//sort both lists in a deterministic fashion
foreach (var list in new[] { allRoutesSerial, allRoutesParallel })
list.Sort((a, b) =>
string.Join(":", a.Select(l => l.FromCity.Name + " " + l.ToCity.Name + " " + l.TransportMode))
.CompareTo(string.Join(":", b.Select(l => l.FromCity.Name + " " + l.ToCity.Name + " " + l.TransportMode))));
//serialize lists to a string
var txtSerial = string.Join("/", allRoutesSerial.Select(i => string.Join(":", i.Select(l => l.FromCity.Name + " " + l.ToCity.Name + " " + l.TransportMode))));
var txtParallel = string.Join("/", allRoutesParallel.Select(i => string.Join(":", i.Select(l => l.FromCity.Name + " " + l.ToCity.Name + " " + l.TransportMode))));
//both algorithms should deliver the same result
Assert.AreEqual(txtSerial, txtParallel);
}
