use lock

Synapse/RpcClient.cs

@@ -42,6 +42,9 @@ public partial class Synapse
 
     private string? FireRpc(string app, string action, object? param, Dictionary<string, string>? headers = null,
         int? timeout = null)
+    {
+        // 检查并发情况下的线程安全问题，使用锁保证字典操作的原子性
+        lock (ResponseCompletionSources)
         {
             string paramJson;
             if (param is string strParam)
@@ -100,3 +103,4 @@ public partial class Synapse
             return response;
         }
     }
+}

Synapse/RpcServer.cs

@@ -20,9 +20,9 @@ public partial class Synapse
 
     private void RunRpcServer()
     {
-        Client!.ApplicationMessageReceivedAsync += e =>
+        Client!.ApplicationMessageReceivedAsync += async e =>
         {
-            Task.Run(() =>
+            await Task.Run(() =>
             {
                 if (!e.ApplicationMessage.Topic.StartsWith(RpcServerTopicPrefix)) return;
                 var reqBody = e.ApplicationMessage.ConvertPayloadToString();
@@ -109,7 +109,6 @@ public partial class Synapse
                     "Synapse Rpc Server Return: ({BasicPropertiesMessageId}) {BasicPropertiesType}@{OptionsAppName} -> {BasicPropertiesReplyTo}\n{ReturnJson}",
                     appInfo[2], action, Options.AppName, appInfo[0], returnJson);
             });
-            return Task.CompletedTask;
         };
         SubRpcServerTopic();
     }