Ryujinx/Ryujinx.Memory/Tracking/RegionHandle.cs
gdkchan 3c60d4b0ea
Do not report unmapped pages as dirty (#1672)
* Do not report unmapped pages as dirty

* Make tests pass again

* PR feedback
2020-11-10 22:07:52 -03:00

136 lines
4.9 KiB
C#

using Ryujinx.Memory.Range;
using System.Collections.Generic;
using System.Threading;
namespace Ryujinx.Memory.Tracking
{
/// <summary>
/// A tracking handle for a given region of virtual memory. The Dirty flag is updated whenever any changes are made,
/// and an action can be performed when the region is read to or written from.
/// </summary>
public class RegionHandle : IRegionHandle, IRange
{
public bool Dirty { get; private set; }
public ulong Address { get; }
public ulong Size { get; }
public ulong EndAddress { get; }
internal IMultiRegionHandle Parent { get; set; }
internal int SequenceNumber { get; set; }
private RegionSignal _preAction; // Action to perform before a read or write. This will block the memory access.
private readonly List<VirtualRegion> _regions;
private readonly MemoryTracking _tracking;
internal MemoryPermission RequiredPermission => _preAction != null ? MemoryPermission.None : (Dirty ? MemoryPermission.ReadAndWrite : MemoryPermission.Read);
/// <summary>
/// Create a new region handle. The handle is registered with the given tracking object,
/// and will be notified of any changes to the specified region.
/// </summary>
/// <param name="tracking">Tracking object for the target memory block</param>
/// <param name="address">Virtual address of the region to track</param>
/// <param name="size">Size of the region to track</param>
/// <param name="dirty">Initial value of the dirty flag</param>
internal RegionHandle(MemoryTracking tracking, ulong address, ulong size, bool dirty = true)
{
Dirty = dirty;
Address = address;
Size = size;
EndAddress = address + size;
_tracking = tracking;
_regions = tracking.GetVirtualRegionsForHandle(address, size);
foreach (var region in _regions)
{
region.Handles.Add(this);
}
}
/// <summary>
/// Signal that a memory action occurred within this handle's virtual regions.
/// </summary>
/// <param name="write">Whether the region was written to or read</param>
internal void Signal(ulong address, ulong size, bool write)
{
RegionSignal action = Interlocked.Exchange(ref _preAction, null);
action?.Invoke(address, size);
if (write)
{
Dirty = true;
Parent?.SignalWrite();
}
}
/// <summary>
/// Consume the dirty flag for this handle, and reprotect so it can be set on the next write.
/// </summary>
public void Reprotect()
{
Dirty = false;
lock (_tracking.TrackingLock)
{
foreach (VirtualRegion region in _regions)
{
region.UpdateProtection();
}
}
}
/// <summary>
/// Register an action to perform when the tracked region is read or written.
/// The action is automatically removed after it runs.
/// </summary>
/// <param name="action">Action to call on read or write</param>
public void RegisterAction(RegionSignal action)
{
RegionSignal lastAction = Interlocked.Exchange(ref _preAction, action);
if (lastAction == null && action != lastAction)
{
lock (_tracking.TrackingLock)
{
foreach (VirtualRegion region in _regions)
{
region.UpdateProtection();
}
}
}
}
/// <summary>
/// Add a child virtual region to this handle.
/// </summary>
/// <param name="region">Virtual region to add as a child</param>
internal void AddChild(VirtualRegion region)
{
_regions.Add(region);
}
/// <summary>
/// Check if this region overlaps with another.
/// </summary>
/// <param name="address">Base address</param>
/// <param name="size">Size of the region</param>
/// <returns>True if overlapping, false otherwise</returns>
public bool OverlapsWith(ulong address, ulong size)
{
return Address < address + size && address < EndAddress;
}
/// <summary>
/// Dispose the handle. Within the tracking lock, this removes references from virtual and physical regions.
/// </summary>
public void Dispose()
{
lock (_tracking.TrackingLock)
{
foreach (VirtualRegion region in _regions)
{
region.RemoveHandle(this);
}
}
}
}
}