From 3ef00d03685beaa38c7c1b50c91e05da79c54922 Mon Sep 17 00:00:00 2001
From: sta <sta.blockhead@gmail.com>
Date: Sun, 24 Sep 2017 19:47:52 +0900
Subject: [PATCH] [Modify] Polish it

---
 .../Server/WebSocketSessionManager.cs         | 41 ++++++++++++-------
 1 file changed, 26 insertions(+), 15 deletions(-)

diff --git a/websocket-sharp/Server/WebSocketSessionManager.cs b/websocket-sharp/Server/WebSocketSessionManager.cs
index bfd908b0..32d59c85 100644
--- a/websocket-sharp/Server/WebSocketSessionManager.cs
+++ b/websocket-sharp/Server/WebSocketSessionManager.cs
@@ -1615,31 +1615,42 @@ namespace WebSocketSharp.Server
     /// </summary>
     public void Sweep ()
     {
-      if (_state != ServerState.Start || _sweeping || Count == 0)
+      if (_sweeping) {
+        _log.Info ("The sweeping is already in progress.");
         return;
+      }
 
       lock (_forSweep) {
+        if (_sweeping) {
+          _log.Info ("The sweeping is already in progress.");
+          return;
+        }
+
         _sweeping = true;
-        foreach (var id in InactiveIDs) {
+      }
+
+      foreach (var id in InactiveIDs) {
+        if (_state != ServerState.Start)
+          break;
+
+        lock (_sync) {
           if (_state != ServerState.Start)
             break;
 
-          lock (_sync) {
-            IWebSocketSession session;
-            if (_sessions.TryGetValue (id, out session)) {
-              var state = session.State;
-              if (state == WebSocketState.Open)
-                session.Context.WebSocket.Close (CloseStatusCode.ProtocolError);
-              else if (state == WebSocketState.Closing)
-                continue;
-              else
-                _sessions.Remove (id);
-            }
+          IWebSocketSession session;
+          if (_sessions.TryGetValue (id, out session)) {
+            var state = session.State;
+            if (state == WebSocketState.Open)
+              session.Context.WebSocket.Close (CloseStatusCode.Abnormal);
+            else if (state == WebSocketState.Closing)
+              continue;
+            else
+              _sessions.Remove (id);
           }
         }
-
-        _sweeping = false;
       }
+
+      _sweeping = false;
     }
 
     /// <summary>