improve user experience for some users

shadowsocks-csharp/Controller/Service/PACServer.cs

@@ -146,7 +146,7 @@ Connection: Close
 ", System.Text.Encoding.UTF8.GetBytes(pac).Length) + pac;
                 byte[] response = System.Text.Encoding.UTF8.GetBytes(text);
                 socket.BeginSend(response, 0, response.Length, 0, new AsyncCallback(SendCallback), socket);
-                Util.Utils.ReleaseMemory();
+                Util.Utils.ReleaseMemory(true);
             }
             catch (Exception e)
             {

shadowsocks-csharp/Controller/ShadowsocksController.cs

@@ -360,7 +360,7 @@ namespace Shadowsocks.Controller
             }
 
             UpdateSystemProxy();
-            Util.Utils.ReleaseMemory();
+            Util.Utils.ReleaseMemory(true);
         }
 
 
@@ -417,7 +417,7 @@ namespace Shadowsocks.Controller
         {
             while (true)
             {
-                Util.Utils.ReleaseMemory();
+                Util.Utils.ReleaseMemory(false);
                 Thread.Sleep(30 * 1000);
             }
         }

shadowsocks-csharp/Program.cs

@@ -18,7 +18,7 @@ namespace Shadowsocks
         [STAThread]
         static void Main()
         {
-            Util.Utils.ReleaseMemory();
+            Util.Utils.ReleaseMemory(true);
             using (Mutex mutex = new Mutex(false, "Global\\Shadowsocks_" + Application.StartupPath.GetHashCode()))
             {
                 Application.EnableVisualStyles();

shadowsocks-csharp/Util/Util.cs

@@ -10,7 +10,7 @@ namespace Shadowsocks.Util
 {
     public class Utils
     {
-        public static void ReleaseMemory()
+        public static void ReleaseMemory(bool removePages)
         {
             // release any unused pages
             // making the numbers look good in task manager
@@ -20,8 +20,29 @@ namespace Shadowsocks.Util
             // which is part of user experience
             GC.Collect(GC.MaxGeneration);
             GC.WaitForPendingFinalizers();
-            SetProcessWorkingSetSize(Process.GetCurrentProcess().Handle,
-                (UIntPtr)0xFFFFFFFF, (UIntPtr)0xFFFFFFFF);
+            if (removePages)
+            {
+                // as some users have pointed out
+                // removing pages from working set will cause some IO
+                // which lowered user experience for another group of users
+                //
+                // so we do 2 more things here to satisfy them:
+                // 1. only remove pages once when configuration is changed
+                // 2. add more comments here to tell users that calling
+                //    this function will not be more frequent than
+                //    IM apps writing chat logs, or web browsers writing cache files
+                //    if they're so concerned about their disk, they should
+                //    uninstall all IM apps and web browsers
+                //
+                // please open an issue if you're worried about anything else in your computer
+                // no matter it's GPU performance, monitor contrast, audio fidelity
+                // or anything else in the task manager
+                // we'll do as much as we can to help you
+                //
+                // just kidding
+                SetProcessWorkingSetSize(Process.GetCurrentProcess().Handle,
+                    (UIntPtr)0xFFFFFFFF, (UIntPtr)0xFFFFFFFF);
+            }
         }
 
         public static string UnGzip(byte[] buf)

shadowsocks-csharp/View/MenuViewController.cs

@@ -322,7 +322,7 @@ namespace Shadowsocks.View
         void configForm_FormClosed(object sender, FormClosedEventArgs e)
         {
             configForm = null;
-            Util.Utils.ReleaseMemory();
+            Util.Utils.ReleaseMemory(true);
             ShowFirstTimeBalloon();
         }