Move partial unmap handler to the native signal handler (#3437)

* Initial commit with a lot of testing stuff.

* Partial Unmap Cleanup Part 1

* Fix some minor issues, hopefully windows tests.

* Disable partial unmap tests on macos for now

Weird issue.

* Goodbye magic number

* Add COMPlus_EnableAlternateStackCheck for tests

`COMPlus_EnableAlternateStackCheck` is needed for NullReferenceException handling to work on linux after registering the signal handler, due to how dotnet registers its own signal handler.

* Address some feedback

* Force retry when memory is mapped in memory tracking

This case existed before, but returning `false` no longer retries, so it would crash immediately after unprotecting the memory... Now, we return `true` to deliberately retry.

This case existed before (was just broken by this change) and I don't really want to look into fixing the issue right now. Technically, this means that on guest code partial unmaps will retry _due to this_ rather than hitting the handler. I don't expect this to cause any issues.

This should fix random crashes in Xenoblade Chronicles 2.

* Use IsRangeMapped

* Suppress MockMemoryManager.UnmapEvent warning

This event is not signalled by the mock memory manager.

* Remove 4kb mapping

1 files changed, 0 insertions, 170 deletions

diff --git a/Ryujinx.Memory/WindowsShared/PlaceholderManager4KB.cs b/Ryujinx.Memory/WindowsShared/PlaceholderManager4KB.cs
deleted file mode 100644
index fc056a2f..00000000
--- a/Ryujinx.Memory/WindowsShared/PlaceholderManager4KB.cs
+++ /dev/null
@@ -1,170 +0,0 @@
-using System;
-using System.Runtime.Versioning;
-
-namespace Ryujinx.Memory.WindowsShared
-{
-    /// <summary>
-    /// Windows 4KB memory placeholder manager.
-    /// </summary>
-    [SupportedOSPlatform("windows")]
-    class PlaceholderManager4KB
-    {
-        private const int PageSize = MemoryManagementWindows.PageSize;
-
-        private readonly IntervalTree<ulong, byte> _mappings;
-
-        /// <summary>
-        /// Creates a new instance of the Windows 4KB memory placeholder manager.
-        /// </summary>
-        public PlaceholderManager4KB()
-        {
-            _mappings = new IntervalTree<ulong, byte>();
-        }
-
-        /// <summary>
-        /// Unmaps the specified range of memory and marks it as mapped internally.
-        /// </summary>
-        /// <remarks>
-        /// Since this marks the range as mapped, the expectation is that the range will be mapped after calling this method.
-        /// </remarks>
-        /// <param name="location">Memory address to unmap and mark as mapped</param>
-        /// <param name="size">Size of the range in bytes</param>
-        public void UnmapAndMarkRangeAsMapped(IntPtr location, IntPtr size)
-        {
-            ulong startAddress = (ulong)location;
-            ulong unmapSize = (ulong)size;
-            ulong endAddress = startAddress + unmapSize;
-
-            var overlaps = Array.Empty<IntervalTreeNode<ulong, byte>>();
-            int count = 0;
-
-            lock (_mappings)
-            {
-                count = _mappings.Get(startAddress, endAddress, ref overlaps);
-            }
-
-            for (int index = 0; index < count; index++)
-            {
-                var overlap = overlaps[index];
-
-                // Tree operations might modify the node start/end values, so save a copy before we modify the tree.
-                ulong overlapStart = overlap.Start;
-                ulong overlapEnd = overlap.End;
-                ulong overlapValue = overlap.Value;
-
-                _mappings.Remove(overlap);
-
-                ulong unmapStart = Math.Max(overlapStart, startAddress);
-                ulong unmapEnd = Math.Min(overlapEnd, endAddress);
-
-                if (overlapStart < startAddress)
-                {
-                    startAddress = overlapStart;
-                }
-
-                if (overlapEnd > endAddress)
-                {
-                    endAddress = overlapEnd;
-                }
-
-                ulong currentAddress = unmapStart;
-                while (currentAddress < unmapEnd)
-                {
-                    WindowsApi.UnmapViewOfFile2(WindowsApi.CurrentProcessHandle, (IntPtr)currentAddress, 2);
-                    currentAddress += PageSize;
-                }
-            }
-
-            _mappings.Add(startAddress, endAddress, 0);
-        }
-
-        /// <summary>
-        /// Unmaps views at the specified memory range.
-        /// </summary>
-        /// <param name="location">Address of the range</param>
-        /// <param name="size">Size of the range in bytes</param>
-        public void UnmapView(IntPtr location, IntPtr size)
-        {
-            ulong startAddress = (ulong)location;
-            ulong unmapSize = (ulong)size;
-            ulong endAddress = startAddress + unmapSize;
-
-            var overlaps = Array.Empty<IntervalTreeNode<ulong, byte>>();
-            int count = 0;
-
-            lock (_mappings)
-            {
-                count = _mappings.Get(startAddress, endAddress, ref overlaps);
-            }
-
-            for (int index = 0; index < count; index++)
-            {
-                var overlap = overlaps[index];
-
-                // Tree operations might modify the node start/end values, so save a copy before we modify the tree.
-                ulong overlapStart = overlap.Start;
-                ulong overlapEnd = overlap.End;
-
-                _mappings.Remove(overlap);
-
-                if (overlapStart < startAddress)
-                {
-                    _mappings.Add(overlapStart, startAddress, 0);
-                }
-
-                if (overlapEnd > endAddress)
-                {
-                    _mappings.Add(endAddress, overlapEnd, 0);
-                }
-
-                ulong unmapStart = Math.Max(overlapStart, startAddress);
-                ulong unmapEnd = Math.Min(overlapEnd, endAddress);
-
-                ulong currentAddress = unmapStart;
-                while (currentAddress < unmapEnd)
-                {
-                    WindowsApi.UnmapViewOfFile2(WindowsApi.CurrentProcessHandle, (IntPtr)currentAddress, 2);
-                    currentAddress += PageSize;
-                }
-            }
-        }
-
-        /// <summary>
-        /// Unmaps mapped memory at a given range.
-        /// </summary>
-        /// <param name="location">Address of the range</param>
-        /// <param name="size">Size of the range in bytes</param>
-        public void UnmapRange(IntPtr location, IntPtr size)
-        {
-            ulong startAddress = (ulong)location;
-            ulong unmapSize = (ulong)size;
-            ulong endAddress = startAddress + unmapSize;
-
-            var overlaps = Array.Empty<IntervalTreeNode<ulong, byte>>();
-            int count = 0;
-
-            lock (_mappings)
-            {
-                count = _mappings.Get(startAddress, endAddress, ref overlaps);
-            }
-
-            for (int index = 0; index < count; index++)
-            {
-                var overlap = overlaps[index];
-
-                // Tree operations might modify the node start/end values, so save a copy before we modify the tree.
-                ulong unmapStart = Math.Max(overlap.Start, startAddress);
-                ulong unmapEnd = Math.Min(overlap.End, endAddress);
-
-                _mappings.Remove(overlap);
-
-                ulong currentAddress = unmapStart;
-                while (currentAddress < unmapEnd)
-                {
-                    WindowsApi.UnmapViewOfFile2(WindowsApi.CurrentProcessHandle, (IntPtr)currentAddress, 2);
-                    currentAddress += PageSize;
-                }
-            }
-        }
-    }
-}
\ No newline at end of file