revert connection close offloaded to threadpool, close blocks

make QuicPeerConnection.Handle the primary accessor for _handle, use interlocked access/manipulation

Author: TYoungSL

StirlingLabs.MsQuic/QuicClientConnection.cs

@@ -137,7 +137,7 @@ private unsafe int ManagedCallback(ref QUIC_CONNECTION_EVENT @event)
     private void OnConnected()
         => Connected?.Invoke(this);
 
-    public override unsafe void Dispose()
+    public override void Dispose()
         => Close();
 
     public unsafe void Start(SizedUtf8String name, ushort port)
@@ -185,5 +185,5 @@ protected override int DefaultCertificateReceivedStatus
         => QUIC_STATUS_SUCCESS;
 
     public override unsafe string ToString()
-        => Name is null ? $"[QuicClientConnection 0x{(ulong)_handle:X}]" : $"[QuicClientConnection \"{Name}\" 0x{(ulong)_handle:X}]";
+        => Name is null ? $"[QuicClientConnection 0x{(ulong)Handle:X}]" : $"[QuicClientConnection \"{Name}\" 0x{(ulong)Handle:X}]";
 }

StirlingLabs.MsQuic/QuicPeerConnection.ReliableDatagrams.cs

@@ -90,6 +90,7 @@ private void AcknowledgeReliableDatagramById(ulong i)
         if (!_reliableDatagramsSentUnacknowledged.TryGetValue(i, out var dg))
             return;
 
+        // ReSharper disable once RedundantAssignment
         var removed = _reliableDatagramsSentUnacknowledged.Remove(i);
         Debug.Assert(removed);
 
@@ -111,7 +112,7 @@ protected internal bool RemoveFromUnacknowledged(IQuicDatagramReliable dg)
     }
 
     [SuppressMessage("Reliability", "CA2000", Justification = "Disposed only after finished sending")]
-    private unsafe bool TrySendDatagramAcks(SortedSet<ulong> toAck)
+    private bool TrySendDatagramAcks(SortedSet<ulong> toAck)
     {
         Debug.Assert(Monitor.IsEntered(_reliableDatagramAckLock));
 
@@ -135,6 +136,7 @@ private unsafe bool TrySendDatagramAcks(SortedSet<ulong> toAck)
 
         span = mem.Span;
 
+        // ReSharper disable once RedundantAssignment
         var headerSizeEncoded = VarIntSqlite4.Encode((ulong)length, span);
         Debug.Assert(headerSize == headerSizeEncoded);
 
@@ -232,13 +234,13 @@ public static unsafe void CleanUpReliableDatagramBuffer(IQuicDatagramReliable dg
         pFirstBuf->Length = 0;
     }
 
-    private IMemoryOwner<byte> _reliableAckPacketBufferOwner;
+    private IMemoryOwner<byte>? _reliableAckPacketBufferOwner;
     private Memory<byte> _reliableAckPacketBuffer;
 
     private void WireUpInboundAcknowledgementStream()
     {
         Debug.Assert(InboundAcknowledgementStream is not null);
-        InboundAcknowledgementStream.Name = "Inbound Reliable Acknowledgement Stream";
+        InboundAcknowledgementStream!.Name = "Inbound Reliable Acknowledgement Stream";
         InboundAcknowledgementStream!.DataReceived += HandleInboundAcknowledgements;
     }
     private void HandleInboundAcknowledgements(QuicStream s)
@@ -280,7 +282,7 @@ private void HandleInboundAcknowledgements(QuicStream s)
                     _reliableAckPacketBuffer = buffer.Slice(0, newSize);
                     var prevOwner = _reliableAckPacketBufferOwner;
                     _reliableAckPacketBufferOwner = owner;
-                    prevOwner.Dispose();
+                    prevOwner?.Dispose();
                     savedNewDataAlready = true;
                     var data = buffer.Span;
 
@@ -332,7 +334,7 @@ private void HandleInboundAcknowledgements(QuicStream s)
                     _reliableAckPacketBuffer = buffer.Slice(0, newSize);
                     var prevOwner = _reliableAckPacketBufferOwner;
                     _reliableAckPacketBufferOwner = owner;
-                    prevOwner.Dispose();
+                    prevOwner?.Dispose();
                 }
                 // save data for next packet
             }

StirlingLabs.MsQuic/QuicPeerConnection.cs

@@ -33,14 +33,14 @@ public abstract partial class QuicPeerConnection : IDisposable
     static QuicPeerConnection()
         => LogTimeStamp.Init();
 
-    protected nint _handle;
+    private nint _handle;
 
     private int _maxSendLength;
 
     public unsafe QUIC_HANDLE* Handle
     {
-        get => (QUIC_HANDLE*)_handle;
-        protected set => _handle = (nint)value;
+        get => (QUIC_HANDLE*)Interlocked.CompareExchange(ref _handle, default, default);
+        protected set => Interlocked.Exchange(ref _handle, (nint)value);
     }
 
     protected GCHandle GcHandle;
@@ -56,7 +56,11 @@ public unsafe QUIC_HANDLE* Handle
     public int QueuedIncomingDatagrams => _incomingDatagramsQueue.Count;
 
     protected int RunState;
+
+    [SuppressMessage("ReSharper", "InconsistentNaming")]
     protected Memory<byte> _resumptionTicket;
+
+    [SuppressMessage("ReSharper", "InconsistentNaming")]
     protected Memory<byte> _resumptionState;
 
     protected QuicPeerConnection(QuicRegistration registration, bool reliableDatagrams)
@@ -158,15 +162,11 @@ public unsafe void Shutdown(bool silent = false)
     public unsafe void Close()
     {
         if (Registration.Disposed) return;
-        const nint zero = default;
-        var handle = Interlocked.Exchange(ref _handle, zero);
-        if (handle is zero) return;
-        ThreadPoolHelpers.QueueUserWorkItemFast(&CloseInternal, (Registration, handle));
+        var handle = (QUIC_HANDLE*)Interlocked.Exchange(ref _handle, default);
+        if (handle == default(QUIC_HANDLE*)) return;
+        Registration.Table.ConnectionClose(handle);
     }
 
-    private static unsafe void CloseInternal((QuicRegistration Registration, nint Handle) state)
-        => state.Registration.Table.ConnectionClose((QUIC_HANDLE*)state.Handle);
-
 
     public QuicDatagram SendDatagram(Memory<byte> data)
     {

StirlingLabs.MsQuic/QuicServerConnection.cs

@@ -205,5 +205,5 @@ protected override int DefaultCertificateReceivedStatus
         => QUIC_STATUS_BAD_CERTIFICATE;
 
     public override unsafe string ToString()
-        => Name is null ? $"[QuicServerConnection 0x{(ulong)_handle:X}]" : $"[QuicServerConnection \"{Name}\" 0x{(ulong)_handle:X}]";
+        => Name is null ? $"[QuicServerConnection 0x{(ulong)Handle:X}]" : $"[QuicServerConnection \"{Name}\" 0x{(ulong)Handle:X}]";
 }