PartialFactorPendingEntry changed back to struct for better performance.

PerfectNumbers.Core/PartialFactorPendingEntry.cs

@@ -2,37 +2,9 @@ using System.Runtime.CompilerServices;
 
 namespace PerfectNumbers.Core;
 
-public sealed class PartialFactorPendingEntry(ulong value, bool knownComposite)
+public struct PartialFactorPendingEntry(ulong value, bool knownComposite)
 {
-	[ThreadStatic]
-	private static PartialFactorPendingEntry? _poolHead;
-	private PartialFactorPendingEntry? _next;
-
-	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-	public static PartialFactorPendingEntry Rent(ulong value, bool knownComposite)
-	{
-		var poolHead = _poolHead;
-		if (poolHead == null)
-		{
-			return new(value, knownComposite);
-		}
-
-		_poolHead = poolHead._next;
-		poolHead.Value = value;
-		poolHead.KnownComposite = knownComposite;
-		poolHead.HasKnownPrimality = knownComposite;
-		poolHead.IsPrime = false;
-		return poolHead;
-	}
-
-	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-	public static void Return(PartialFactorPendingEntry entry)
-	{
-		entry._next = _poolHead;
-		_poolHead = entry;
-	}
-
-	public ulong Value = value;
+	public readonly ulong Value = value;
 	public bool KnownComposite = knownComposite;
 	public bool HasKnownPrimality = knownComposite;
 	public bool IsPrime = false;

PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs

@@ -1336,13 +1336,15 @@ internal static partial class PrimeOrderCalculator
 				{
 					while (compositeStack.Count > 0)
 					{
-						pending.Add(PartialFactorPendingEntry.Rent(compositeStack.Pop(), knownComposite: false));
+						pending.Add(new(compositeStack.Pop(), knownComposite: false));
+						// pending.Add(PartialFactorPendingEntry.Rent(compositeStack.Pop(), knownComposite: false));
 					}
 				}
 			}
 			else
 			{
-				pending.Add(PartialFactorPendingEntry.Rent(remaining, knownComposite: false));
+				pending.Add(new (remaining, knownComposite: false));
+				// pending.Add(PartialFactorPendingEntry.Rent(remaining, knownComposite: false));
 			}
 		}
 
@@ -1360,7 +1362,6 @@ internal static partial class PrimeOrderCalculator
 			{
 				cofactor = checked(cofactor * composite);
 				cofactorContainsComposite = true;
-				PartialFactorPendingEntry.Return(entry);
 				continue;
 			}
 
@@ -1382,8 +1383,6 @@ internal static partial class PrimeOrderCalculator
 				cofactor = checked(cofactor * composite);
 				cofactorContainsComposite = true;
 			}
-
-			PartialFactorPendingEntry.Return(entry);
 		}
 
 		bool cofactorIsPrime;
@@ -1442,13 +1441,13 @@ internal static partial class PrimeOrderCalculator
 			pollardRhoDeadlineReached = Stopwatch.GetTimestamp() > deadlineTimestamp;
 			if (pollardRhoDeadlineReached)
 			{
-				pending.Add(PartialFactorPendingEntry.Rent(composite, knownComposite: true));
+				pending.Add(new (composite, knownComposite: true));
 				continue;
 			}
 
 			if (!TryPollardRhoCpu(composite, deadlineTimestamp, out ulong factor))
 			{
-				pending.Add(PartialFactorPendingEntry.Rent(composite, knownComposite: true));
+				pending.Add(new (composite, knownComposite: true));
 				continue;
 			}