From cd6266bb04aed401245862a18670f5fb8d76ba69 Mon Sep 17 00:00:00 2001
From: dudu <dudu@cnblogs.com>
Date: Mon, 30 Nov 2020 14:22:09 +0800
Subject: [PATCH 1/2] Fix socket pool starvation

---
 Enyim.Caching/Memcached/MemcachedNode.cs | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/Enyim.Caching/Memcached/MemcachedNode.cs b/Enyim.Caching/Memcached/MemcachedNode.cs
index 547d9f31..830649f9 100755
--- a/Enyim.Caching/Memcached/MemcachedNode.cs
+++ b/Enyim.Caching/Memcached/MemcachedNode.cs
@@ -551,10 +551,11 @@ public async Task<IPooledSocketResult> AcquireAsync()
                 // maybe we died while waiting
                 if (!this.isAlive)
                 {
+                    _semaphore.Release();
+
                     message = "Pool is dead, returning null. " + _endPoint;
                     if (_isDebugEnabled) _logger.LogDebug(message);
                     result.Fail(message);
-
                     return result;
                 }
 
@@ -573,9 +574,11 @@ public async Task<IPooledSocketResult> AcquireAsync()
                         }
                         else
                         {
+                            _semaphore.Release();
+                            retval.IsAlive = false;
+
                             message = "Timeout to reset an acquired socket. InstanceId " + retval.InstanceId;
                             _logger.LogError(message);
-                            MarkAsDead();
                             result.Fail(message);
                             return result;
                         }
@@ -589,10 +592,11 @@ public async Task<IPooledSocketResult> AcquireAsync()
                     }
                     catch (Exception e)
                     {
+                        MarkAsDead();
+                        _semaphore.Release();
+
                         message = "Failed to reset an acquired socket.";
                         _logger.LogError(message, e);
-
-                        this.MarkAsDead();
                         result.Fail(message, e);
                         return result;
                     }
@@ -945,7 +949,6 @@ protected virtual async Task<IPooledSocketResult> ExecuteOperationAsync(IOperati
                 _logger.LogError(errorMsg);
                 return result;
             }
-
         }
 
         protected virtual async Task<bool> ExecuteOperationAsync(IOperation op, Action<bool> next)

From f0dcbb5e26f0f6f7cf77a17d9777c90ffb037c38 Mon Sep 17 00:00:00 2001
From: dudu <dudu@cnblogs.com>
Date: Tue, 1 Dec 2020 15:48:22 +0800
Subject: [PATCH 2/2] Add netstandard2.0 to TargetFrameworks

---
 Enyim.Caching/Enyim.Caching.csproj | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Enyim.Caching/Enyim.Caching.csproj b/Enyim.Caching/Enyim.Caching.csproj
index ec299fc2..cb2c1e1f 100755
--- a/Enyim.Caching/Enyim.Caching.csproj
+++ b/Enyim.Caching/Enyim.Caching.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <Description>EnyimMemcachedCore is a Memcached client library for .NET Core. Usage: Add services.AddEnyimMemcached(...) and app.UseEnyimMemcached() in Startup. Add IMemcachedClient into constructor.</Description>
     <Authors>cnblogs.com</Authors>
-    <TargetFrameworks>netstandard2.1;net5.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netstandard2.1;net5.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <AssemblyName>EnyimMemcachedCore</AssemblyName>
     <PackageId>EnyimMemcachedCore</PackageId>