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| author | TSR Berry <20988865+TSRBerry@users.noreply.github.com> | 2023-04-08 01:22:00 +0200 |
|---|---|---|
| committer | Mary <thog@protonmail.com> | 2023-04-27 23:51:14 +0200 |
| commit | cee712105850ac3385cd0091a923438167433f9f (patch) | |
| tree | 4a5274b21d8b7f938c0d0ce18736d3f2993b11b1 /src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs | |
| parent | cd124bda587ef09668a971fa1cac1c3f0cfc9f21 (diff) | |
Move solution and projects to src
Diffstat (limited to 'src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs')
| -rw-r--r-- | src/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs | 152 |
1 files changed, 152 insertions, 0 deletions
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); + } + } + } +} |