From 8f0cc17d90ffa8df21efb867bfdc23736e6e614e Mon Sep 17 00:00:00 2001
From: mlemanczyk <marek@lemanczyk.eu>
Date: Thu, 11 Dec 2025 21:46:07 +0100
Subject: [PATCH] PoolingSemaphore optimized.

---
 PerfectNumbers.Core/PollingSemaphore.cs | 138 +++++++++++-------------
 1 file changed, 63 insertions(+), 75 deletions(-)

diff --git a/PerfectNumbers.Core/PollingSemaphore.cs b/PerfectNumbers.Core/PollingSemaphore.cs
index 04aed76..3259b9e 100644
--- a/PerfectNumbers.Core/PollingSemaphore.cs
+++ b/PerfectNumbers.Core/PollingSemaphore.cs
@@ -9,95 +9,83 @@ namespace PerfectNumbers.Core;
 /// </summary>
 public sealed class PollingSemaphore
 {
-    private readonly int _maximumConcurrency;
-    private readonly TimeSpan _pauseBetweenChecks;
-    private readonly bool _hasPause;
-    private int _currentHolders;
+	private readonly int _maximumConcurrency;
+	private readonly TimeSpan _pauseBetweenChecks;
+	private readonly bool _hasPause;
+	private int _currentHolders;
 
-    public PollingSemaphore(int maximumConcurrency, TimeSpan pauseBetweenChecks)
-    {
-        if (maximumConcurrency <= 0)
-        {
-            throw new ArgumentOutOfRangeException(nameof(maximumConcurrency));
-        }
+	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+	public PollingSemaphore(int maximumConcurrency, TimeSpan pauseBetweenChecks)
+	{
+		ArgumentOutOfRangeException.ThrowIfLessThanOrEqual(maximumConcurrency, 0);
+		ArgumentOutOfRangeException.ThrowIfLessThan(pauseBetweenChecks, TimeSpan.Zero);
 
-        if (pauseBetweenChecks < TimeSpan.Zero)
-        {
-            throw new ArgumentOutOfRangeException(nameof(pauseBetweenChecks));
-        }
+		_maximumConcurrency = maximumConcurrency;
+		_pauseBetweenChecks = pauseBetweenChecks;
+		_hasPause = pauseBetweenChecks > TimeSpan.Zero;
+	}
 
-        _maximumConcurrency = maximumConcurrency;
-        _pauseBetweenChecks = pauseBetweenChecks;
-        _hasPause = pauseBetweenChecks > TimeSpan.Zero;
-    }
+	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+	public bool TryEnter()
+	{
+		int newValue = Interlocked.Increment(ref _currentHolders);
+		if (newValue <= _maximumConcurrency)
+		{
+			return true;
+		}
 
-    public bool TryEnter()
-    {
-        int newValue = Interlocked.Increment(ref _currentHolders);
+		Interlocked.Decrement(ref _currentHolders);
+		return false;
+	}
 
-        if (newValue <= _maximumConcurrency)
-        {
-            return true;
-        }
-
-        Interlocked.Decrement(ref _currentHolders);
-        return false;
-    }
-
-    public bool Wait(TimeSpan timeout, CancellationToken cancellationToken = default)
-    {
+	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+	public bool Wait(TimeSpan timeout, CancellationToken cancellationToken = default)
+	{
 		ArgumentOutOfRangeException.ThrowIfLessThan(timeout, Timeout.InfiniteTimeSpan);
 
-		Stopwatch? stopwatch = timeout == Timeout.InfiniteTimeSpan ? null : Stopwatch.StartNew();
-        SpinWait spinner = new();
+		bool hasPause = _hasPause;
+		bool hasStopwatch = timeout != Timeout.InfiniteTimeSpan;
+		SpinWait spinner = new();
+		TimeSpan pauseBetweenChecks = _pauseBetweenChecks;
+		Stopwatch? stopwatch = hasStopwatch ? Stopwatch.StartNew() : null;
+		while (true)
+		{
+			cancellationToken.ThrowIfCancellationRequested();
 
-        while (true)
-        {
-            cancellationToken.ThrowIfCancellationRequested();
+			if (TryEnter())
+			{
+				return true;
+			}
 
-            if (TryEnter())
-            {
-                return true;
-            }
+			if (hasStopwatch && stopwatch!.Elapsed >= timeout)
+			{
+				return false;
+			}
 
-            if (stopwatch is not null && stopwatch.Elapsed >= timeout)
-            {
-                return false;
-            }
+			if (spinner.Count < 10)
+			{
+				spinner.SpinOnce();
+				continue;
+			}
 
-            if (spinner.Count < 10)
-            {
-                spinner.SpinOnce();
-                continue;
-            }
+			if (hasPause)
+			{
+				Thread.Sleep(pauseBetweenChecks);
+				spinner.Reset();
+			}
+			else
+			{
+				Thread.Yield();
+			}
+		}
+	}
 
-            if (_hasPause)
-            {
-                Thread.Sleep(_pauseBetweenChecks);
-                spinner.Reset();
-            }
-            else
-            {
-                Thread.Yield();
-            }
-        }
-    }
-
-	[MethodImpl(MethodImplOptions.AggressiveInlining)]
+	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
 	public bool Wait(CancellationToken cancellationToken) => Wait(Timeout.InfiniteTimeSpan, cancellationToken);
 
-	[MethodImpl(MethodImplOptions.AggressiveInlining)]
+	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
 	public bool Wait() => Wait(Timeout.InfiniteTimeSpan, CancellationToken.None);
 
-	[MethodImpl(MethodImplOptions.AggressiveInlining)]
-	public void Release()
-    {
-        int newValue = Interlocked.Decrement(ref _currentHolders);
-
-        if (newValue < 0)
-        {
-            Interlocked.Increment(ref _currentHolders);
-            throw new SynchronizationLockException("Release called more times than Wait.");
-        }
-    }
+	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+	public void Release() => _ = Interlocked.Decrement(ref _currentHolders);
 }