Memory.Unsafe

Unsafe methods for working with unmanaged memory and pointers.

Description

Unsafe methods for working with pointers and unmanaged memory in a completely generic, not-type-safe way.

Code Quality Rank: L5

Programming language: C#

License: MIT License

Tags: Performance     Profiler     Memory     Optimization     Unsafe     unmanaged     pointer     pointers     generic    

README

Memory.Unsafe

Unsafe methods for working with pointers and unmanaged memory in a completely generic, not-type-safe way.

NuGet

The current NuGet package name is DotNetCross.Memory.Unsafe. It can be found here:

https://www.nuget.org/packages/DotNetCross.Memory.Unsafe

OBSOLETE NuGet Package Name and URL

Unfortunately, I made the mistake of including .dll in the package name when I first created the nuspec-file. This was later fixed (version >= 0.2.2.0), but also means people who have been referring to the package via DotNetCross.Memory.Unsafe.dll may not know this was changed to DotNetCross.Memory.Unsafe. Unfortunately, there was no way to redirect or rename the old package so users could be informed of this change.

Official .NET Core Package

The Unsafe class has now been added to .NET Core and exists as a separate package:

https://www.nuget.org/packages/System.Runtime.CompilerServices.Unsafe/

If in doubt, use this official package.

API

API surface can be see in [src/DotNetCross.Memory.Unsafe.Ref/Unsafe.cs](src/DotNetCross.Memory.Unsafe.Ref/Unsafe.cs).

Examples

Read

var ptr = stackalloc int[1];
*ptr = 42;
var v = Unsafe.Read<int>(ptr);
Assert.Equal(42, v);

Write

var ptr = stackalloc int[1];
*ptr = 17;
Unsafe.Write<int>(ptr, 42);
Assert.Equal(42, ptr[0]);

SizeOf

var size = Unsafe.SizeOf<T>();

As + AsPointer

var array = new int[2];
array[0] = 42;
array[1] = 17;
fixed (void* pinPtr = &Unsafe.As<Pinnable>(array).Pin)
{
    void* firstPtr = Unsafe.AsPointer(ref array[0]);

    Assert.Equal(42, Unsafe.Read<int>(firstPtr));
    Assert.Equal(17, Unsafe.Read<int>((byte*)firstPtr + sizeof(int)));
}

CopyBlock

var src = stackalloc byte[2];
src[0] = src[1] = 0x12;
var dest = stackalloc short[1];
Unsafe.CopyBlock(dest, src, 2);
Assert.Equal(0x1212, dest[0]);

InitBlock

var ptr = stackalloc byte[10];
Unsafe.InitBlock(ptr, 123, 10);
for (int i = 0; i < 10; i++)
    Assert.Equal(123, ptr[i]);