diff options
| author | riperiperi <rhy3756547@hotmail.com> | 2022-10-29 23:07:37 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-10-29 22:07:37 +0000 |
| commit | 3d98e1361b2f1c3993aa7f1e9b1ac49fc5b6e512 (patch) | |
| tree | 010767e20636e9837652a0133fc1ef40838c942e /Ryujinx.Memory/Tracking/ConcurrentBitmap.cs | |
| parent | 141cf61ff72224c394cab4e5e252907d0cdb797a (diff) | |
GPU: Use a bitmap to track buffer modified flags. (#3775)1.1.335
* Initial implementation
* Some improvements.
* Fix incorrect cast
* Performance improvement and improved correctness
* Add very fast path when all handles are checked.
* Slightly faster
* Add comment
* De-virtualize region handle
All region handles are now bitmap backed.
* Remove non-bitmap tracking
* Remove unused methods
* Add docs, remove unused methods
* Address Feedback
* Rename file
Diffstat (limited to 'Ryujinx.Memory/Tracking/ConcurrentBitmap.cs')
| -rw-r--r-- | Ryujinx.Memory/Tracking/ConcurrentBitmap.cs | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs b/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs new file mode 100644 index 00000000..2e007bb5 --- /dev/null +++ b/Ryujinx.Memory/Tracking/ConcurrentBitmap.cs @@ -0,0 +1,161 @@ +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 (Volatile.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 (Volatile.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 = Volatile.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 (Volatile.Read(ref Masks[i]) != 0) + { + return true; + } + } + + long endValue = Volatile.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; + + long existing; + long newValue; + + do + { + existing = Volatile.Read(ref Masks[wordIndex]); + + if (value) + { + newValue = existing | wordMask; + } + else + { + newValue = existing & ~wordMask; + } + } + while (Interlocked.CompareExchange(ref Masks[wordIndex], newValue, existing) != existing); + } + + /// <summary> + /// Clear the bitmap entirely, setting all bits to 0. + /// </summary> + public void Clear() + { + for (int i = 0; i < Masks.Length; i++) + { + Volatile.Write(ref Masks[i], 0); + } + } + } +} |