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Add SafeBuffer Span<T> methods #40842

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Merged
jkotas merged 7 commits into from
Sep 1, 2020
Merged

Add SafeBuffer Span<T> methods #40842

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11b964a
Implement SafeBuffer.ReadSpan and WriteSpan.
huoyaoyuan Aug 14, 2020
a7fe4e5
Add reference source for SafeBuffer.
huoyaoyuan Aug 14, 2020
596d7ec
Apply review comments and remove unnecessary checks.
huoyaoyuan Aug 15, 2020
ad1ff4a
Add empty span test for SafeBuffer.
huoyaoyuan Aug 15, 2020
32a84f8
Add roundtrip tests for SafeBuffer.
huoyaoyuan Aug 15, 2020
983ecfb
Remove redundant stackalloc span test.
huoyaoyuan Sep 1, 2020
7a13653
Apply suggestions from code review
jkotas Sep 1, 2020
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38 changes: 22 additions & 16 deletions src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/SafeBuffer.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -217,26 +217,30 @@ public void ReadArray<T>(ulong byteOffset, T[] array, int index, int count)
if (array.Length - index < count)
throw new ArgumentException(SR.Argument_InvalidOffLen);

ReadSpan(byteOffset, new Span<T>(array, index, count));
}

[CLSCompliant(false)]
public void ReadSpan<T>(ulong byteOffset, Span<T> buffer)
where T : struct
{
if (_numBytes == Uninitialized)
throw NotInitialized();

uint sizeofT = SizeOf<T>();
uint alignedSizeofT = AlignedSizeOf<T>();
byte* ptr = (byte*)handle + byteOffset;
SpaceCheck(ptr, checked((nuint)(alignedSizeofT * count)));
SpaceCheck(ptr, checked((nuint)(alignedSizeofT * buffer.Length)));

bool mustCallRelease = false;
try
{
DangerousAddRef(ref mustCallRelease);

if (count > 0)
fixed (byte* pStructure = &Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(buffer)))
{
fixed (byte* pStructure = &Unsafe.As<T, byte>(ref array[index]))
{
for (int i = 0; i < count; i++)
Buffer.Memmove(pStructure + sizeofT * i, ptr + alignedSizeofT * i, sizeofT);
}
for (int i = 0; i < buffer.Length; i++)
Buffer.Memmove(pStructure + sizeofT * i, ptr + alignedSizeofT * i, sizeofT);
}
}
finally
Expand Down Expand Up @@ -293,28 +297,30 @@ public void WriteArray<T>(ulong byteOffset, T[] array, int index, int count)
if (array.Length - index < count)
throw new ArgumentException(SR.Argument_InvalidOffLen);

WriteSpan(byteOffset, new ReadOnlySpan<T>(array, index, count));
}

[CLSCompliant(false)]
public void WriteSpan<T>(ulong byteOffset, ReadOnlySpan<T> data)
where T : struct
{
if (_numBytes == Uninitialized)
throw NotInitialized();

uint sizeofT = SizeOf<T>();
uint alignedSizeofT = AlignedSizeOf<T>();
byte* ptr = (byte*)handle + byteOffset;
SpaceCheck(ptr, checked((nuint)(alignedSizeofT * count)));
SpaceCheck(ptr, checked((nuint)(alignedSizeofT * data.Length)));

bool mustCallRelease = false;
try
{
DangerousAddRef(ref mustCallRelease);

if (count > 0)
fixed (byte* pStructure = &Unsafe.As<T, byte>(ref MemoryMarshal.GetReference(data)))
{
{
fixed (byte* pStructure = &Unsafe.As<T, byte>(ref array[index]))
{
for (int i = 0; i < count; i++)
Buffer.Memmove(ptr + alignedSizeofT * i, pStructure + sizeofT * i, sizeofT);
}
}
for (int i = 0; i < data.Length; i++)
Buffer.Memmove(ptr + alignedSizeofT * i, pStructure + sizeofT * i, sizeofT);
}
}
finally
Expand Down
94 changes: 94 additions & 0 deletions ...es/System.Runtime.InteropServices/tests/System/Runtime/InteropServices/SafeBufferTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,16 @@ public void ReadArray_NullArray_ThrowsArgumentNullException()
AssertExtensions.Throws<ArgumentNullException>("array", () => wrapper.WriteArray<int>(0, null, 0, 0));
}

[Fact]
public void ReadWriteSpan_EmptySpan_Passes()
{
var buffer = new SubBuffer(true);
buffer.Initialize(0);

buffer.ReadSpan<int>(0, Span<int>.Empty);
buffer.WriteSpan<int>(0, ReadOnlySpan<int>.Empty);
}

[Fact]
public void ReadArray_NegativeIndex_ThrowsArgumentOutOfRangeException()
{
Expand Down Expand Up @@ -121,6 +131,68 @@ public void ByteLength_GetNotInitialized_ThrowsInvalidOperationException()
Assert.Throws<InvalidOperationException>(() => wrapper.ByteLength);
}

[Fact]
public void ReadWrite_RoundTrip()
{
using var buffer = new HGlobalBuffer(100);

int intValue = 1234;
buffer.Write<int>(0, intValue);
Assert.Equal(intValue, buffer.Read<int>(0));

double doubleValue = 123.45;
buffer.Write<double>(10, doubleValue);
Assert.Equal(doubleValue, buffer.Read<double>(10));

TestStruct structValue = new TestStruct
{
I = 1234,
L = 987654321,
D = double.MaxValue
};
buffer.Write<TestStruct>(0, structValue);
Assert.Equal(structValue, buffer.Read<TestStruct>(0));
}

[Fact]
public void ReadWriteSpanArray_RoundTrip()
{
using var buffer = new HGlobalBuffer(200);

int[] intArray = new int[] { 11, 22, 33, 44 };
TestArray(intArray);
TestSpan<int>(intArray);

TestStruct[] structArray = new TestStruct[]
{
new TestStruct { I = 11, L = 22, D = 33 },
new TestStruct { I = 44, L = 55, D = 66 },
new TestStruct { I = 77, L = 88, D = 99 },
new TestStruct { I = 100, L = 200, D = 300 },
};
TestArray(structArray);
TestSpan<TestStruct>(structArray);

void TestArray<T>(T[] data)
where T : struct
{
T[] destination = new T[data.Length];
buffer.WriteArray(0, data, 0, data.Length);
buffer.ReadArray(0, destination, 0, data.Length);
Assert.Equal(data, destination);
}

void TestSpan<T>(ReadOnlySpan<T> data)
where T : unmanaged
{
Span<T> destination = stackalloc T[data.Length];
buffer.WriteSpan(0, data);
buffer.ReadSpan(0, destination);
for (int i = 0; i < data.Length; i++)
Assert.Equal(data[i], destination[i]);
}
}

public class SubBuffer : SafeBuffer
{
public SubBuffer(bool ownsHandle) : base(ownsHandle) { }
Expand All @@ -130,5 +202,27 @@ protected override bool ReleaseHandle()
throw new NotImplementedException();
}
}

public class HGlobalBuffer : SafeBuffer
{
public HGlobalBuffer(int length) : base(true)
{
SetHandle(Marshal.AllocHGlobal(length));
Initialize((ulong)length);
}

protected override bool ReleaseHandle()
{
Marshal.FreeHGlobal(handle);
return true;
}
}

public struct TestStruct
{
public int I;
public long L;
public double D;
}
}
}
4 changes: 4 additions & 0 deletions src/libraries/System.Runtime/ref/System.Runtime.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -9736,11 +9736,15 @@ public void Initialize<T>(uint numElements) where T : struct { }
[System.CLSCompliantAttribute(false)]
public void ReadArray<T>(ulong byteOffset, T[] array, int index, int count) where T : struct { }
[System.CLSCompliantAttribute(false)]
public void ReadSpan<T>(ulong byteOffset, System.Span<T> buffer) where T : struct { }
[System.CLSCompliantAttribute(false)]
public T Read<T>(ulong byteOffset) where T : struct { throw null; }
public void ReleasePointer() { }
[System.CLSCompliantAttribute(false)]
public void WriteArray<T>(ulong byteOffset, T[] array, int index, int count) where T : struct { }
[System.CLSCompliantAttribute(false)]
public void WriteSpan<T>(ulong byteOffset, System.ReadOnlySpan<T> data) where T : struct { }
[System.CLSCompliantAttribute(false)]
public void Write<T>(ulong byteOffset, T value) where T : struct { }
}
public abstract partial class SafeHandle : System.Runtime.ConstrainedExecution.CriticalFinalizerObject, System.IDisposable
Expand Down