From 8bfcbdebf3bdab1022fc02feb339f51537540639 Mon Sep 17 00:00:00 2001
From: TheLastRar <TheLastRar@users.noreply.github.com>
Date: Mon, 29 Apr 2024 22:38:33 +0100
Subject: [PATCH] DEV9: Defer deletion of socket sessions

---
 pcsx2/DEV9/sockets.cpp | 46 ++++++++++++++++++++++++++++++++++++------
 pcsx2/DEV9/sockets.h   |  4 ++++
 2 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/pcsx2/DEV9/sockets.cpp b/pcsx2/DEV9/sockets.cpp
index 9dc65a574af39..4c1aae975db33 100644
--- a/pcsx2/DEV9/sockets.cpp
+++ b/pcsx2/DEV9/sockets.cpp
@@ -3,6 +3,7 @@
 
 #include "common/Assertions.h"
 #include "common/StringUtil.h"
+#include "common/ScopedGuard.h"
 
 #ifdef _WIN32
 #include <winsock2.h>
@@ -216,6 +217,8 @@ SocketAdapter::SocketAdapter()
 		wsa_init = true;
 #endif
 
+	sendThreadId = std::this_thread::get_id();
+
 	initialized = true;
 }
 
@@ -234,6 +237,13 @@ bool SocketAdapter::recv(NetPacket* pkt)
 	if (NetAdapter::recv(pkt))
 		return true;
 
+	ScopedGuard cleanup([&]() {
+		// Garbage collect closed connections
+		for (BaseSession* s : deleteQueueRecvThread)
+			delete s;
+		deleteQueueRecvThread.clear();
+	});
+
 	EthernetFrame* bFrame;
 	if (!vRecBuffer.Dequeue(&bFrame))
 	{
@@ -282,6 +292,14 @@ bool SocketAdapter::send(NetPacket* pkt)
 	if (NetAdapter::send(pkt))
 		return true;
 
+	pxAssert(std::this_thread::get_id() == sendThreadId);
+	ScopedGuard cleanup([&]() {
+		// Garbage collect closed connections
+		for (BaseSession* s : deleteQueueSendThread)
+			delete s;
+		deleteQueueSendThread.clear();
+	});
+
 	EthernetFrame frame(pkt);
 
 	switch (frame.protocol)
@@ -548,9 +566,12 @@ void SocketAdapter::HandleConnectionClosed(BaseSession* sender)
 {
 	const ConnectionKey key = sender->key;
 	connections.Remove(key);
-	//Note, we delete something that is calling us
-	//this is probably going to cause issues
-	delete sender;
+
+	// Defer deleting the connection untill we have left the calling session's callstack
+	if (std::this_thread::get_id() == sendThreadId)
+		deleteQueueSendThread.push_back(sender);
+	else
+		deleteQueueRecvThread.push_back(sender);
 
 	switch (key.protocol)
 	{
@@ -577,9 +598,12 @@ void SocketAdapter::HandleFixedPortClosed(BaseSession* sender)
 	ConnectionKey key = sender->key;
 	connections.Remove(key);
 	fixedUDPPorts.Remove(key.ps2Port);
-	//Note, we delete something that is calling us
-	//this is probably going to cause issues
-	delete sender;
+
+	// Defer deleting the connection untill we have left the calling session's callstack
+	if (std::this_thread::get_id() == sendThreadId)
+		deleteQueueSendThread.push_back(sender);
+	else
+		deleteQueueRecvThread.push_back(sender);
 
 	Console.WriteLn("DEV9: Socket: Closed Dead UDP Fixed Port to %d", key.ps2Port);
 }
@@ -604,6 +628,16 @@ SocketAdapter::~SocketAdapter()
 	connections.Clear();
 	fixedUDPPorts.Clear(); //fixedUDP sessions already deleted via connections
 
+	//Clear out any delete queues
+	DevCon.WriteLn("DEV9: Socket: Found %d Connections in send delete queue", deleteQueueSendThread.size());
+	DevCon.WriteLn("DEV9: Socket: Found %d Connections in recv delete queue", deleteQueueRecvThread.size());
+	for (BaseSession* s : deleteQueueSendThread)
+		delete s;
+	for (BaseSession* s : deleteQueueRecvThread)
+		delete s;
+	deleteQueueSendThread.clear();
+	deleteQueueRecvThread.clear();
+
 	//Clear out vRecBuffer
 	while (!vRecBuffer.IsQueueEmpty())
 	{
diff --git a/pcsx2/DEV9/sockets.h b/pcsx2/DEV9/sockets.h
index ca062c4eb8252..b6acf451f87bd 100644
--- a/pcsx2/DEV9/sockets.h
+++ b/pcsx2/DEV9/sockets.h
@@ -28,6 +28,10 @@ class SocketAdapter : public NetAdapter
 	ThreadSafeMap<Sessions::ConnectionKey, Sessions::BaseSession*> connections;
 	ThreadSafeMap<u16, Sessions::BaseSession*> fixedUDPPorts;
 
+	std::thread::id sendThreadId;
+	std::vector<Sessions::BaseSession*> deleteQueueSendThread;
+	std::vector<Sessions::BaseSession*> deleteQueueRecvThread;
+
 public:
 	SocketAdapter();
 	virtual bool blocks();