diff --git a/shadowsocks-csharp/Controller/FileManager.cs b/shadowsocks-csharp/Controller/FileManager.cs
index f15a1cc1..7769be43 100755
--- a/shadowsocks-csharp/Controller/FileManager.cs
+++ b/shadowsocks-csharp/Controller/FileManager.cs
@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.IO.Compression;
+using System.Text;
 
 namespace Shadowsocks.Controller
 {
@@ -39,5 +40,19 @@ namespace Shadowsocks.Controller
                 }
             }
         }
+
+        public static string NonExclusiveReadAllText(string path)
+        {
+            return NonExclusiveReadAllText(path, Encoding.Default);
+        }
+
+        public static string NonExclusiveReadAllText(string path, Encoding encoding)
+        {
+            using (var fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
+            using (var sr = new StreamReader(fs, encoding))
+            {
+                return sr.ReadToEnd();
+            }
+        }
     }
 }
diff --git a/shadowsocks-csharp/Controller/Service/GfwListUpdater.cs b/shadowsocks-csharp/Controller/Service/GfwListUpdater.cs
index 3d04fafc..30cd7d34 100644
--- a/shadowsocks-csharp/Controller/Service/GfwListUpdater.cs
+++ b/shadowsocks-csharp/Controller/Service/GfwListUpdater.cs
@@ -39,7 +39,7 @@ namespace Shadowsocks.Controller
                 List<string> lines = ParseResult(e.Result);
                 if (File.Exists(PACServer.USER_RULE_FILE))
                 {
-                    string local = File.ReadAllText(PACServer.USER_RULE_FILE, Encoding.UTF8);
+                    string local = FileManager.NonExclusiveReadAllText(PACServer.USER_RULE_FILE, Encoding.UTF8);
                     using (var sr = new StringReader(local))
                     {
                         foreach (var rule in sr.NonWhiteSpaceLines())
@@ -53,7 +53,7 @@ namespace Shadowsocks.Controller
                 string abpContent;
                 if (File.Exists(PACServer.USER_ABP_FILE))
                 {
-                    abpContent = File.ReadAllText(PACServer.USER_ABP_FILE, Encoding.UTF8);
+                    abpContent = FileManager.NonExclusiveReadAllText(PACServer.USER_ABP_FILE, Encoding.UTF8);
                 }
                 else
                 {
@@ -62,7 +62,7 @@ namespace Shadowsocks.Controller
                 abpContent = abpContent.Replace("__RULES__", JsonConvert.SerializeObject(lines, Formatting.Indented));
                 if (File.Exists(PACServer.PAC_FILE))
                 {
-                    string original = File.ReadAllText(PACServer.PAC_FILE, Encoding.UTF8);
+                    string original = FileManager.NonExclusiveReadAllText(PACServer.PAC_FILE, Encoding.UTF8);
                     if (original == abpContent)
                     {
                         UpdateCompleted(this, new ResultEventArgs(false));
diff --git a/shadowsocks-csharp/Controller/ShadowsocksController.cs b/shadowsocks-csharp/Controller/ShadowsocksController.cs
index c287bd29..9ec544d9 100644
--- a/shadowsocks-csharp/Controller/ShadowsocksController.cs
+++ b/shadowsocks-csharp/Controller/ShadowsocksController.cs
@@ -557,10 +557,10 @@ namespace Shadowsocks.Controller
                 UpdatePACFromGFWList();
                 return;
             }
-            List<string> lines = GFWListUpdater.ParseResult(File.ReadAllText(Utils.GetTempPath("gfwlist.txt")));
+            List<string> lines = GFWListUpdater.ParseResult(FileManager.NonExclusiveReadAllText(Utils.GetTempPath("gfwlist.txt")));
             if (File.Exists(PACServer.USER_RULE_FILE))
             {
-                string local = File.ReadAllText(PACServer.USER_RULE_FILE, Encoding.UTF8);
+                string local = FileManager.NonExclusiveReadAllText(PACServer.USER_RULE_FILE, Encoding.UTF8);
                 using (var sr = new StringReader(local))
                 {
                     foreach (var rule in sr.NonWhiteSpaceLines())
@@ -574,7 +574,7 @@ namespace Shadowsocks.Controller
             string abpContent;
             if (File.Exists(PACServer.USER_ABP_FILE))
             {
-                abpContent = File.ReadAllText(PACServer.USER_ABP_FILE, Encoding.UTF8);
+                abpContent = FileManager.NonExclusiveReadAllText(PACServer.USER_ABP_FILE, Encoding.UTF8);
             }
             else
             {
@@ -583,7 +583,7 @@ namespace Shadowsocks.Controller
             abpContent = abpContent.Replace("__RULES__", JsonConvert.SerializeObject(lines, Formatting.Indented));
             if (File.Exists(PACServer.PAC_FILE))
             {
-                string original = File.ReadAllText(PACServer.PAC_FILE, Encoding.UTF8);
+                string original = FileManager.NonExclusiveReadAllText(PACServer.PAC_FILE, Encoding.UTF8);
                 if (original == abpContent)
                 {
                     return;