Ryujinx/Ryujinx.Memory/MemoryBlock.cs
2021-07-10 21:50:10 +02:00

388 lines
19 KiB
C#

using System;
using System.Runtime.CompilerServices;
using System.Threading;
namespace Ryujinx.Memory
{
/// <summary>
/// Represents a block of contiguous physical guest memory.
/// </summary>
public sealed class MemoryBlock : IWritableBlock, IDisposable
{
private readonly bool _usesSharedMemory;
private readonly bool _isMirror;
private IntPtr _sharedMemory;
private IntPtr _pointer;
/// <summary>
/// Pointer to the memory block data.
/// </summary>
public IntPtr Pointer => _pointer;
/// <summary>
/// Size of the memory block.
/// </summary>
public ulong Size { get; }
/// <summary>
/// Creates a new instance of the memory block class.
/// </summary>
/// <param name="size">Size of the memory block in bytes</param>
/// <param name="flags">Flags that controls memory block memory allocation</param>
/// <exception cref="OutOfMemoryException">Throw when there's no enough memory to allocate the requested size</exception>
/// <exception cref="PlatformNotSupportedException">Throw when the current platform is not supported</exception>
public MemoryBlock(ulong size, MemoryAllocationFlags flags = MemoryAllocationFlags.None)
{
if (flags.HasFlag(MemoryAllocationFlags.Mirrorable))
{
_sharedMemory = MemoryManagement.CreateSharedMemory(size, flags.HasFlag(MemoryAllocationFlags.Reserve));
_pointer = MemoryManagement.MapSharedMemory(_sharedMemory);
_usesSharedMemory = true;
}
else if (flags.HasFlag(MemoryAllocationFlags.Reserve))
{
_pointer = MemoryManagement.Reserve(size);
}
else
{
_pointer = MemoryManagement.Allocate(size);
}
Size = size;
}
/// <summary>
/// Creates a new instance of the memory block class, with a existing backing storage.
/// </summary>
/// <param name="size">Size of the memory block in bytes</param>
/// <param name="sharedMemory">Shared memory to use as backing storage for this block</param>
/// <exception cref="OutOfMemoryException">Throw when there's no enough address space left to map the shared memory</exception>
/// <exception cref="PlatformNotSupportedException">Throw when the current platform is not supported</exception>
private MemoryBlock(ulong size, IntPtr sharedMemory)
{
_pointer = MemoryManagement.MapSharedMemory(sharedMemory);
Size = size;
_usesSharedMemory = true;
_isMirror = true;
}
/// <summary>
/// Creates a memory block that shares the backing storage with this block.
/// The memory and page commitments will be shared, however memory protections are separate.
/// </summary>
/// <returns>A new memory block that shares storage with this one</returns>
/// <exception cref="NotSupportedException">Throw when the current memory block does not support mirroring</exception>
/// <exception cref="OutOfMemoryException">Throw when there's no enough address space left to map the shared memory</exception>
/// <exception cref="PlatformNotSupportedException">Throw when the current platform is not supported</exception>
public MemoryBlock CreateMirror()
{
if (_sharedMemory == IntPtr.Zero)
{
throw new NotSupportedException("Mirroring is not supported on the memory block because the Mirrorable flag was not set.");
}
return new MemoryBlock(Size, _sharedMemory);
}
/// <summary>
/// Commits a region of memory that has previously been reserved.
/// This can be used to allocate memory on demand.
/// </summary>
/// <param name="offset">Starting offset of the range to be committed</param>
/// <param name="size">Size of the range to be committed</param>
/// <returns>True if the operation was successful, false otherwise</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
public bool Commit(ulong offset, ulong size)
{
return MemoryManagement.Commit(GetPointerInternal(offset, size), size);
}
/// <summary>
/// Decommits a region of memory that has previously been reserved and optionally comitted.
/// This can be used to free previously allocated memory on demand.
/// </summary>
/// <param name="offset">Starting offset of the range to be decommitted</param>
/// <param name="size">Size of the range to be decommitted</param>
/// <returns>True if the operation was successful, false otherwise</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
public bool Decommit(ulong offset, ulong size)
{
return MemoryManagement.Decommit(GetPointerInternal(offset, size), size);
}
/// <summary>
/// Reprotects a region of memory.
/// </summary>
/// <param name="offset">Starting offset of the range to be reprotected</param>
/// <param name="size">Size of the range to be reprotected</param>
/// <param name="permission">New memory permissions</param>
/// <param name="throwOnFail">True if a failed reprotect should throw</param>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
/// <exception cref="MemoryProtectionException">Throw when <paramref name="permission"/> is invalid</exception>
public void Reprotect(ulong offset, ulong size, MemoryPermission permission, bool throwOnFail = true)
{
MemoryManagement.Reprotect(GetPointerInternal(offset, size), size, permission, throwOnFail);
}
/// <summary>
/// Remaps a region of memory into this memory block.
/// </summary>
/// <param name="offset">Starting offset of the range to be remapped into</param>
/// <param name="sourceAddress">Starting offset of the range to be remapped from</param>
/// <param name="size">Size of the range to be remapped</param>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
/// <exception cref="MemoryProtectionException">Throw when <paramref name="permission"/> is invalid</exception>
public void Remap(ulong offset, IntPtr sourceAddress, ulong size)
{
MemoryManagement.Remap(GetPointerInternal(offset, size), sourceAddress, size);
}
/// <summary>
/// Reads bytes from the memory block.
/// </summary>
/// <param name="offset">Starting offset of the range being read</param>
/// <param name="data">Span where the bytes being read will be copied to</param>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when the memory region specified for the the data is out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void Read(ulong offset, Span<byte> data)
{
GetSpan(offset, data.Length).CopyTo(data);
}
/// <summary>
/// Reads data from the memory block.
/// </summary>
/// <typeparam name="T">Type of the data</typeparam>
/// <param name="offset">Offset where the data is located</param>
/// <returns>Data at the specified address</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when the memory region specified for the the data is out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public T Read<T>(ulong offset) where T : unmanaged
{
return GetRef<T>(offset);
}
/// <summary>
/// Writes bytes to the memory block.
/// </summary>
/// <param name="offset">Starting offset of the range being written</param>
/// <param name="data">Span where the bytes being written will be copied from</param>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when the memory region specified for the the data is out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void Write(ulong offset, ReadOnlySpan<byte> data)
{
data.CopyTo(GetSpan(offset, data.Length));
}
/// <summary>
/// Writes data to the memory block.
/// </summary>
/// <typeparam name="T">Type of the data being written</typeparam>
/// <param name="offset">Offset to write the data into</param>
/// <param name="data">Data to be written</param>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when the memory region specified for the the data is out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void Write<T>(ulong offset, T data) where T : unmanaged
{
GetRef<T>(offset) = data;
}
/// <summary>
/// Copies data from one memory location to another.
/// </summary>
/// <param name="dstOffset">Destination offset to write the data into</param>
/// <param name="srcOffset">Source offset to read the data from</param>
/// <param name="size">Size of the copy in bytes</param>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when <paramref name="srcOffset"/>, <paramref name="dstOffset"/> or <paramref name="size"/> is out of range</exception>
public void Copy(ulong dstOffset, ulong srcOffset, ulong size)
{
const int MaxChunkSize = 1 << 24;
for (ulong offset = 0; offset < size; offset += MaxChunkSize)
{
int copySize = (int)Math.Min(MaxChunkSize, size - offset);
Write(dstOffset + offset, GetSpan(srcOffset + offset, copySize));
}
}
/// <summary>
/// Fills a region of memory with zeros.
/// </summary>
/// <param name="offset">Offset of the region to fill with zeros</param>
/// <param name="size">Size in bytes of the region to fill</param>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
public void ZeroFill(ulong offset, ulong size)
{
const int MaxChunkSize = 1 << 24;
for (ulong subOffset = 0; subOffset < size; subOffset += MaxChunkSize)
{
int copySize = (int)Math.Min(MaxChunkSize, size - subOffset);
GetSpan(offset + subOffset, copySize).Fill(0);
}
}
/// <summary>
/// Gets a reference of the data at a given memory block region.
/// </summary>
/// <typeparam name="T">Data type</typeparam>
/// <param name="offset">Offset of the memory region</param>
/// <returns>A reference to the given memory region data</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public unsafe ref T GetRef<T>(ulong offset) where T : unmanaged
{
IntPtr ptr = _pointer;
if (ptr == IntPtr.Zero)
{
ThrowObjectDisposed();
}
int size = Unsafe.SizeOf<T>();
ulong endOffset = offset + (ulong)size;
if (endOffset > Size || endOffset < offset)
{
ThrowInvalidMemoryRegionException();
}
return ref Unsafe.AsRef<T>((void*)PtrAddr(ptr, offset));
}
/// <summary>
/// Gets the pointer of a given memory block region.
/// </summary>
/// <param name="offset">Start offset of the memory region</param>
/// <param name="size">Size in bytes of the region</param>
/// <returns>The pointer to the memory region</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public nuint GetPointer(ulong offset, ulong size) => (nuint)(ulong)GetPointerInternal(offset, size);
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private IntPtr GetPointerInternal(ulong offset, ulong size)
{
IntPtr ptr = _pointer;
if (ptr == IntPtr.Zero)
{
ThrowObjectDisposed();
}
ulong endOffset = offset + size;
if (endOffset > Size || endOffset < offset)
{
ThrowInvalidMemoryRegionException();
}
return PtrAddr(ptr, offset);
}
/// <summary>
/// Gets the <see cref="Span{T}"/> of a given memory block region.
/// </summary>
/// <param name="offset">Start offset of the memory region</param>
/// <param name="size">Size in bytes of the region</param>
/// <returns>Span of the memory region</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public unsafe Span<byte> GetSpan(ulong offset, int size)
{
return new Span<byte>((void*)GetPointerInternal(offset, (ulong)size), size);
}
/// <summary>
/// Gets the <see cref="Memory{T}"/> of a given memory block region.
/// </summary>
/// <param name="offset">Start offset of the memory region</param>
/// <param name="size">Size in bytes of the region</param>
/// <returns>Memory of the memory region</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public unsafe Memory<byte> GetMemory(ulong offset, int size)
{
return new NativeMemoryManager<byte>((byte*)GetPointerInternal(offset, (ulong)size), size).Memory;
}
/// <summary>
/// Gets a writable region of a given memory block region.
/// </summary>
/// <param name="offset">Start offset of the memory region</param>
/// <param name="size">Size in bytes of the region</param>
/// <returns>Writable region of the memory region</returns>
/// <exception cref="ObjectDisposedException">Throw when the memory block has already been disposed</exception>
/// <exception cref="InvalidMemoryRegionException">Throw when either <paramref name="offset"/> or <paramref name="size"/> are out of range</exception>
public WritableRegion GetWritableRegion(ulong offset, int size)
{
return new WritableRegion(null, offset, GetMemory(offset, size));
}
/// <summary>
/// Adds a 64-bits offset to a native pointer.
/// </summary>
/// <param name="pointer">Native pointer</param>
/// <param name="offset">Offset to add</param>
/// <returns>Native pointer with the added offset</returns>
private IntPtr PtrAddr(IntPtr pointer, ulong offset)
{
return (IntPtr)(pointer.ToInt64() + (long)offset);
}
/// <summary>
/// Frees the memory allocated for this memory block.
/// </summary>
/// <remarks>
/// It's an error to use the memory block after disposal.
/// </remarks>
public void Dispose() => FreeMemory();
~MemoryBlock() => FreeMemory();
private void FreeMemory()
{
IntPtr ptr = Interlocked.Exchange(ref _pointer, IntPtr.Zero);
// If pointer is null, the memory was already freed or never allocated.
if (ptr != IntPtr.Zero)
{
if (_usesSharedMemory)
{
MemoryManagement.UnmapSharedMemory(ptr);
if (_sharedMemory != IntPtr.Zero && !_isMirror)
{
MemoryManagement.DestroySharedMemory(_sharedMemory);
_sharedMemory = IntPtr.Zero;
}
}
else
{
MemoryManagement.Free(ptr);
}
}
}
private void ThrowObjectDisposed() => throw new ObjectDisposedException(nameof(MemoryBlock));
private void ThrowInvalidMemoryRegionException() => throw new InvalidMemoryRegionException();
}
}