Updated version

CryptoExchange.Net/Clients/RestApiClient.cs

@@ -558,7 +558,7 @@ namespace CryptoExchange.Net
         {
             // Handle retry after header
             var retryAfterHeader = responseHeaders.SingleOrDefault(r => r.Key.Equals("Retry-After", StringComparison.InvariantCultureIgnoreCase));
-            if (!retryAfterHeader.Value.Any())
+            if (retryAfterHeader.Value?.Any() != true)
                 return new ServerRateLimitError(data);
 
             var value = retryAfterHeader.Value.First();

CryptoExchange.Net/CryptoExchange.Net.csproj

@@ -6,16 +6,16 @@
     <PackageId>CryptoExchange.Net</PackageId>
     <Authors>JKorf</Authors>
     <Description>A base package for implementing cryptocurrency API's</Description>
-    <PackageVersion>6.1.1</PackageVersion>
-    <AssemblyVersion>6.1.1</AssemblyVersion>
-    <FileVersion>6.1.1</FileVersion>
+    <PackageVersion>6.1.3</PackageVersion>
+    <AssemblyVersion>6.1.3</AssemblyVersion>
+    <FileVersion>6.1.3</FileVersion>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
     <RepositoryType>git</RepositoryType>
     <RepositoryUrl>https://github.com/JKorf/CryptoExchange.Net.git</RepositoryUrl>
     <PackageProjectUrl>https://github.com/JKorf/CryptoExchange.Net</PackageProjectUrl>
     <NeutralLanguage>en</NeutralLanguage>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
-    <PackageReleaseNotes>6.1.1 - Fixes for json converters</PackageReleaseNotes>
+    <PackageReleaseNotes>6.1.3 - Fix for concurrency exception in socket subscription</PackageReleaseNotes>
     <Nullable>enable</Nullable>
     <LangVersion>10.0</LangVersion>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>

CryptoExchange.Net/Objects/RateLimiter.cs

@@ -117,10 +117,10 @@ namespace CryptoExchange.Net.Objects
         {
             int totalWaitTime = 0;
 
-            EndpointRateLimiter? endpointLimit;
+            List<EndpointRateLimiter> endpointLimits;
             lock (_limiterLock)
-                endpointLimit = _limiters.OfType<EndpointRateLimiter>().SingleOrDefault(h => h.Endpoints.Contains(endpoint) && (h.Method  == null || h.Method == method));
-            if(endpointLimit != null)
+                endpointLimits = _limiters.OfType<EndpointRateLimiter>().Where(h => h.Endpoints.Contains(endpoint) && (h.Method  == null || h.Method == method)).ToList();
+            foreach (var endpointLimit in endpointLimits)
             {
                 var waitResult = await ProcessTopic(logger, endpointLimit, endpoint, requestWeight, limitBehaviour, ct).ConfigureAwait(false);
                 if (!waitResult)
@@ -129,7 +129,7 @@ namespace CryptoExchange.Net.Objects
                 totalWaitTime += waitResult.Data;
             }
 
-            if (endpointLimit?.IgnoreOtherRateLimits == true)
+            if (endpointLimits.Any(l => l.IgnoreOtherRateLimits))
                 return new CallResult<int>(totalWaitTime);
 
             List<PartialEndpointRateLimiter> partialEndpointLimits;
@@ -169,10 +169,10 @@ namespace CryptoExchange.Net.Objects
             if(partialEndpointLimits.Any(p => p.IgnoreOtherRateLimits))
                 return new CallResult<int>(totalWaitTime);
 
-            ApiKeyRateLimiter? apiLimit;
+            List<ApiKeyRateLimiter> apiLimits;
             lock (_limiterLock)
-                apiLimit = _limiters.OfType<ApiKeyRateLimiter>().SingleOrDefault(h => h.Type == RateLimitType.ApiKey);
-            if (apiLimit != null)
+                apiLimits = _limiters.OfType<ApiKeyRateLimiter>().Where(h => h.Type == RateLimitType.ApiKey).ToList();
+            foreach (var apiLimit in apiLimits)
             {
                 if(apiKey == null)
                 {
@@ -206,13 +206,13 @@ namespace CryptoExchange.Net.Objects
                 }
             }
 
-            if ((signed || apiLimit?.OnlyForSignedRequests == false) && apiLimit?.IgnoreTotalRateLimit == true)
+            if ((signed || apiLimits.All(l => !l.OnlyForSignedRequests)) && apiLimits.Any(l => l.IgnoreTotalRateLimit))
                 return new CallResult<int>(totalWaitTime);
 
-            TotalRateLimiter? totalLimit;
+            List<TotalRateLimiter> totalLimits;
             lock (_limiterLock)
-                totalLimit = _limiters.OfType<TotalRateLimiter>().SingleOrDefault();
-            if (totalLimit != null)
+                totalLimits = _limiters.OfType<TotalRateLimiter>().ToList();
+            foreach(var totalLimit in  totalLimits) 
             {
                 var waitResult = await ProcessTopic(logger, totalLimit, endpoint, requestWeight, limitBehaviour, ct).ConfigureAwait(false);
                 if (!waitResult)

CryptoExchange.Net/Sockets/CryptoExchangeWebSocketClient.cs

@@ -278,7 +278,7 @@ namespace CryptoExchange.Net.Sockets
                 return;
 
             var bytes = Parameters.Encoding.GetBytes(data);
-            _logger.Log(LogLevel.Trace, $"Socket {Id} - msg {id} - Adding {bytes.Length} to send buffer");
+            _logger.Log(LogLevel.Trace, $"Socket {Id} - msg {id} - Adding {bytes.Length} bytes to send buffer");
             _sendBuffer.Enqueue(new SendItem { Id = id, Weight = weight, Bytes = bytes });
             _sendEvent.Set();
         }

CryptoExchange.Net/Sockets/SocketConnection.cs

@@ -291,10 +291,13 @@ namespace CryptoExchange.Net.Sockets
         /// <param name="requestId">Id of the request sent</param>
         protected virtual void HandleRequestSent(int requestId)
         {
-            var pendingRequest = _pendingRequests.SingleOrDefault(p => p.Id == requestId);
+            PendingRequest pendingRequest;
+            lock (_pendingRequests)
+                pendingRequest = _pendingRequests.SingleOrDefault(p => p.Id == requestId);
+
             if (pendingRequest == null)
             {
-                _logger.Log(LogLevel.Debug, $"Socket {SocketId} - msg {requestId} -  message sent, but not pending");
+                _logger.Log(LogLevel.Debug, $"Socket {SocketId} - msg {requestId} - message sent, but not pending");
                 return;
             }
 
@@ -380,7 +383,7 @@ namespace CryptoExchange.Net.Sockets
                                                 "Data from this socket may arrive late or not at all if message processing is continuously slow.");
             }
 
-            _logger.Log(LogLevel.Trace, $"Socket {SocketId}{(subscription == null ? "" : " subscription " + subscription!.Id)} message processed in {(int)total.TotalMilliseconds}ms, ({(int)userProcessTime.TotalMilliseconds}ms user code)");
+            _logger.Log(LogLevel.Trace, $"Socket {SocketId}{(subscription == null ? "" : " subscription " + subscription!.Id)} message processed in {(int)total.TotalMilliseconds}ms ({(int)userProcessTime.TotalMilliseconds}ms user code)");
         }
 
         /// <summary>

README.md

@@ -31,6 +31,13 @@ Make a one time donation in a crypto currency of your choice. If you prefer to d
 Alternatively, sponsor me on Github using [Github Sponsors](https://github.com/sponsors/JKorf). 
 
 ## Release notes
+* Version 6.1.3 - 18 Sep 2023
+    * Fix for concurrency exception in socket subscription
+
+* Version 6.1.2 - 11 Sep 2023
+    * Added support for multiple of the same ratelimiting type in the same rate limiter
+    * Fixed nullreference on rate limit error if no Retry-After header is returned
+
 * Version 6.1.1 - 04 Sep 2023
     * Fixes for json converters