internal void RunPLINQExamples()
{
// TODO
// --------------------------------------------------------------------------------------------
// Speed Comparison LINQ vs PLINQ
string text = StringData.CreateLongString();
List <string> searchWords = new List <string> {
"Gott", "Mann", "Weib", "Mensch", "Teufel", "Hass", "Gnade", "und", "Brot", "Wein", "oder", "Hund", "Apfel"
};
DateTime current = DateTime.UtcNow;
var results = searchWords.Select(w => new
{
Word = w,
Count = text.Split(new char[] { ' ', '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries).Count(a => a == w)
}).ToArray();
Console.Write("[LINQvsPLINQ] LINQ needs {0:0.000}s while ", (DateTime.UtcNow - current).TotalSeconds);
current = DateTime.UtcNow;
results = searchWords.AsParallel().Select(w => new
{
Word = w,
Count = text.Split(new char[] { ' ', '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries).Count(a => a == w)
}).ToArray();
Console.WriteLine("PLINQ needs {0:0.000}s", (DateTime.UtcNow - current).TotalSeconds);
}
internal void RunParallelExamples()
{
Stopwatch watch = new Stopwatch();
// --------------------------------------------------------------------------------------------
// Mit der Klasse Parallel können relativ einfach parallele Aufgaben erzeugt und abgearbeitet werden
//
// --------------------------------------------------------------------------------------------
// Gibt 0 bis 9 in beliebiger Reihenfolge aus, da jeder Thread
// zu einem anderen Zeitpunkt ausgeführt werden könnte.
Console.Write("[Parallel.For] Results = ");
Parallel.For(0, 10, a => Console.Write("{0}, ", a));
Console.WriteLine();
// --------------------------------------------------------------------------------------------
//Parallel.For(0, 50, a => a).
// --------------------------------------------------------------------------------------------
// Parallel.ForEach
// With Parallel.ForEach() an IEnumerable can be used to create tasks easily.
watch.Restart();
string text = StringData.CreateLongString();
Console.Write("[Parallel.ForEach.Simple] Results = ");
List <string> searchWords = new List <string> {
"Gott", "Mann", "Weib"
};
Parallel.ForEach(searchWords, a => Console.Write("{0}({1}) ", a, text
.Split(new char[] { ' ', '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries)
.Count(b => string.Compare(a, b, true) == 0)));
Console.WriteLine("in {0:0.000}s", watch.Elapsed.TotalSeconds);
// --------------------------------------------------------------------------------------------
// Parallel.ForEach Options
// Additionally one can use the ParallelOptions to setup some stuff, here the max amount of Tasks used.
// Others are using a different TaskFactory oder including a CancelationToken.
watch.Restart();
Console.Write("[Parallel.ForEach.Complex] Results = ");
Parallel.ForEach(
searchWords,
new ParallelOptions {
MaxDegreeOfParallelism = 2,
}, // Default for MaxDegreeOfParallelism is -1
(w, s) =>
{
int count = text
.Split(new char[] { ' ', '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries)
.Count(b => string.Compare(w, b, true) == 0);
Console.Write("{0}({1}) ", w, count);
});
Console.WriteLine("in {0:0.000}s", watch.Elapsed.TotalSeconds);
// --------------------------------------------------------------------------------------------
// Parallel.ForEach Break
// With Break the Parallel exceution can be stopped. If break was called the next task will not be started.
watch.Restart();
searchWords = new List <string> {
"Gott", "Mann", "Weib", "Mensch", "Teufel", // "Hass", "Gnade", "Brot", "Wein", "Hund", "Tot"
};
Console.Write("[Parallel.ForEach.Break] Break results ");
ParallelLoopResult result = Parallel.ForEach(
searchWords,
new ParallelOptions {
MaxDegreeOfParallelism = 2,
},
(w, s) =>
{
int count = text
.Split(new char[] { ' ', '\n', '\r' }, StringSplitOptions.RemoveEmptyEntries)
.Count(b => string.Compare(w, b, true) == 0);
if (count < 20)
{
s.Break();
}
});
Console.Write("in {0:0.000}s ", watch.Elapsed.TotalSeconds);
Console.WriteLine("while LowestBreakIteration = {0}, Completed = {1}", result.LowestBreakIteration, result.IsCompleted);
}
