From 3a2aed681177fb786797c16436bdc47c90167852 Mon Sep 17 00:00:00 2001
From: Omar Gonzalez <ogonzalez@secretdoorgames.com>
Date: Wed, 14 Jul 2021 12:38:03 -0700
Subject: [PATCH 1/3] Fixed deadlock in caller's Task.WhenAll

When Task.Factory.StartNew is called with an already cancelled token, the resulting task never reaches completed.
---
 Open.Nat/Discovery/Searcher.cs | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/Open.Nat/Discovery/Searcher.cs b/Open.Nat/Discovery/Searcher.cs
index b409fc6..9108fc2 100644
--- a/Open.Nat/Discovery/Searcher.cs
+++ b/Open.Nat/Discovery/Searcher.cs
@@ -61,16 +61,19 @@ public Task<IEnumerable<NatDevice>> Search(CancellationToken cancelationToken)
 #else
 		public async Task<IEnumerable<NatDevice>> Search(CancellationToken cancelationToken)
 		{
-			await Task.Factory.StartNew(_ =>
-				{
-					NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
-					while (!cancelationToken.IsCancellationRequested)
-					{
-						Discover(cancelationToken);
-						Receive(cancelationToken);
-					}
-					CloseUdpClients();
-				}, null, cancelationToken);
+            if (!cancelationToken.IsCancellationRequested)
+            {
+                await Task.Factory.StartNew(_ =>
+                    {
+                        NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
+                        while (!cancelationToken.IsCancellationRequested)
+                        {
+                            Discover(cancelationToken);
+                            Receive(cancelationToken);
+                        }
+                        CloseUdpClients();
+                    }, null, cancelationToken);
+            }
 			return _devices;
 		}
 #endif

From a9a90cc3e8fdc5166acb11613688c523a432aa1e Mon Sep 17 00:00:00 2001
From: Omar Gonzalez <ogonzalez@dreamhaven.com>
Date: Mon, 10 Jan 2022 14:17:10 -0800
Subject: [PATCH 2/3] Replace IsCancellationRequested with
 ThrowIfCancellationRequested

Also switched to tabs
---
 Open.Nat/Discovery/Searcher.cs | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/Open.Nat/Discovery/Searcher.cs b/Open.Nat/Discovery/Searcher.cs
index 9108fc2..61c237c 100644
--- a/Open.Nat/Discovery/Searcher.cs
+++ b/Open.Nat/Discovery/Searcher.cs
@@ -46,6 +46,8 @@ internal abstract class Searcher
 #if NET35
 		public Task<IEnumerable<NatDevice>> Search(CancellationToken cancelationToken)
 		{
+			cancelationToken.ThrowIfCancellationRequested();
+
 			return Task.Factory.StartNew(_ =>
 			{
 				NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
@@ -61,19 +63,18 @@ public Task<IEnumerable<NatDevice>> Search(CancellationToken cancelationToken)
 #else
 		public async Task<IEnumerable<NatDevice>> Search(CancellationToken cancelationToken)
 		{
-            if (!cancelationToken.IsCancellationRequested)
-            {
-                await Task.Factory.StartNew(_ =>
-                    {
-                        NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
-                        while (!cancelationToken.IsCancellationRequested)
-                        {
-                            Discover(cancelationToken);
-                            Receive(cancelationToken);
-                        }
-                        CloseUdpClients();
-                    }, null, cancelationToken);
-            }
+			cancelationToken.ThrowIfCancellationRequested();
+
+			await Task.Factory.StartNew(_ =>
+			{
+				NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
+				while (!cancelationToken.IsCancellationRequested)
+				{
+					Discover(cancelationToken);
+					Receive(cancelationToken);
+				}
+				CloseUdpClients();
+			}, null, cancelationToken);
 			return _devices;
 		}
 #endif

From b34cf0d986125f44192e1c87cbbde6096cd8d974 Mon Sep 17 00:00:00 2001
From: Omar Gonzalez <ogonzalez@dreamhaven.com>
Date: Mon, 10 Jan 2022 14:19:25 -0800
Subject: [PATCH 3/3] Fixed indent level

---
 Open.Nat/Discovery/Searcher.cs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/Open.Nat/Discovery/Searcher.cs b/Open.Nat/Discovery/Searcher.cs
index 61c237c..76c7636 100644
--- a/Open.Nat/Discovery/Searcher.cs
+++ b/Open.Nat/Discovery/Searcher.cs
@@ -66,15 +66,15 @@ public async Task<IEnumerable<NatDevice>> Search(CancellationToken cancelationTo
 			cancelationToken.ThrowIfCancellationRequested();
 
 			await Task.Factory.StartNew(_ =>
-			{
-				NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
-				while (!cancelationToken.IsCancellationRequested)
 				{
-					Discover(cancelationToken);
-					Receive(cancelationToken);
-				}
-				CloseUdpClients();
-			}, null, cancelationToken);
+					NatDiscoverer.TraceSource.LogInfo("Searching for: {0}", GetType().Name);
+					while (!cancelationToken.IsCancellationRequested)
+					{
+						Discover(cancelationToken);
+						Receive(cancelationToken);
+					}
+					CloseUdpClients();
+				}, null, cancelationToken);
 			return _devices;
 		}
 #endif