From cee712105850ac3385cd0091a923438167433f9f Mon Sep 17 00:00:00 2001
From: TSR Berry <20988865+TSRBerry@users.noreply.github.com>
Date: Sat, 8 Apr 2023 01:22:00 +0200
Subject: Move solution and projects to src

---
 src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs | 152 ++++++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs

(limited to 'src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs')

diff --git a/src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs b/src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs
new file mode 100644
index 00000000..994fda92
--- /dev/null
+++ b/src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs
@@ -0,0 +1,152 @@
+using System;
+using System.Threading;
+
+namespace Ryujinx.Memory.Tracking
+{
+    /// <summary>
+    /// A bitmap that can be safely modified from multiple threads.
+    /// </summary>
+    internal class ConcurrentBitmap
+    {
+        public const int IntSize = 64;
+
+        public const int IntShift = 6;
+        public const int IntMask = IntSize - 1;
+
+        /// <summary>
+        /// Masks representing the bitmap. Least significant bit first, 64-bits per mask.
+        /// </summary>
+        public readonly long[] Masks;
+
+        /// <summary>
+        /// Create a new multithreaded bitmap.
+        /// </summary>
+        /// <param name="count">The number of bits to reserve</param>
+        /// <param name="set">Whether the bits should be initially set or not</param>
+        public ConcurrentBitmap(int count, bool set)
+        {
+            Masks = new long[(count + IntMask) / IntSize];
+
+            if (set)
+            {
+                Array.Fill(Masks, -1L);
+            }
+        }
+
+        /// <summary>
+        /// Check if any bit in the bitmap is set.
+        /// </summary>
+        /// <returns>True if any bits are set, false otherwise</returns>
+        public bool AnySet()
+        {
+            for (int i = 0; i < Masks.Length; i++)
+            {
+                if (Interlocked.Read(ref Masks[i]) != 0)
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Check if a bit in the bitmap is set.
+        /// </summary>
+        /// <param name="bit">The bit index to check</param>
+        /// <returns>True if the bit is set, false otherwise</returns>
+        public bool IsSet(int bit)
+        {
+            int wordIndex = bit >> IntShift;
+            int wordBit = bit & IntMask;
+
+            long wordMask = 1L << wordBit;
+
+            return (Interlocked.Read(ref Masks[wordIndex]) & wordMask) != 0;
+        }
+
+        /// <summary>
+        /// Check if any bit in a range of bits in the bitmap are set. (inclusive)
+        /// </summary>
+        /// <param name="start">The first bit index to check</param>
+        /// <param name="end">The last bit index to check</param>
+        /// <returns>True if a bit is set, false otherwise</returns>
+        public bool IsSet(int start, int end)
+        {
+            if (start == end)
+            {
+                return IsSet(start);
+            }
+
+            int startIndex = start >> IntShift;
+            int startBit = start & IntMask;
+            long startMask = -1L << startBit;
+
+            int endIndex = end >> IntShift;
+            int endBit = end & IntMask;
+            long endMask = (long)(ulong.MaxValue >> (IntMask - endBit));
+
+            long startValue = Interlocked.Read(ref Masks[startIndex]);
+
+            if (startIndex == endIndex)
+            {
+                return (startValue & startMask & endMask) != 0;
+            }
+
+            if ((startValue & startMask) != 0)
+            {
+                return true;
+            }
+
+            for (int i = startIndex + 1; i < endIndex; i++)
+            {
+                if (Interlocked.Read(ref Masks[i]) != 0)
+                {
+                    return true;
+                }
+            }
+
+            long endValue = Interlocked.Read(ref Masks[endIndex]);
+
+            if ((endValue & endMask) != 0)
+            {
+                return true;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Set a bit at a specific index to either true or false.
+        /// </summary>
+        /// <param name="bit">The bit index to set</param>
+        /// <param name="value">Whether the bit should be set or not</param>
+        public void Set(int bit, bool value)
+        {
+            int wordIndex = bit >> IntShift;
+            int wordBit = bit & IntMask;
+
+            long wordMask = 1L << wordBit;
+
+            if (value)
+            {
+                Interlocked.Or(ref Masks[wordIndex], wordMask);
+            }
+            else
+            {
+                Interlocked.And(ref Masks[wordIndex], ~wordMask);
+            }
+        }
+
+        /// <summary>
+        /// Clear the bitmap entirely, setting all bits to 0.
+        /// </summary>
+        public void Clear()
+        {
+            for (int i = 0; i < Masks.Length; i++)
+            {
+                Interlocked.Exchange(ref Masks[i], 0);
+            }
+        }
+    }
+}
-- 
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