use a named mutex to guard against starting a new server

inorton · Mar 27, 2014 · 7b38482 · 7b38482
1 parent 7ee6a23
commit 7b38482
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Showing 3 changed files with 31 additions and 31 deletions.
diff --git a/CClash/CClashServer.cs b/CClash/CClashServer.cs
@@ -5,6 +5,7 @@
 using System.IO;
 using System.IO.Pipes;
 using System.Web.Script.Serialization;
+using System.Threading;
 
 namespace CClash
 {
@@ -35,19 +36,26 @@ void YieldLocks()
         public void Listen(string cachedir)
         {
 
-            try
-            {
+            var mtx = new Mutex(false, "cclash_serv_" + cachedir.ToLower().GetHashCode());
+
+            try {
+                if (!mtx.WaitOne(500)) {
+                    return; // some other process is holding it
+                }
+            } catch (AbandonedMutexException) {
+                // past server must have died!
+            }
+
+            try {
                 Logging.Emit("server listening..");
 
-                using (var nss = new NamedPipeServerStream(MakePipeName(cachedir), PipeDirection.InOut, 1, PipeTransmissionMode.Message, PipeOptions.WriteThrough | PipeOptions.Asynchronous))
-                {
+                using (var nss = new NamedPipeServerStream(MakePipeName(cachedir), PipeDirection.InOut, 1, PipeTransmissionMode.Message, PipeOptions.WriteThrough | PipeOptions.Asynchronous)) {
                     cache = new DirectCompilerCacheServer(cachedir);
                     var msgbuf = new List<byte>();
-                    var rxbuf = new byte[256*1024];
+                    var rxbuf = new byte[256 * 1024];
                     DateTime lastConnection = DateTime.Now;
-
-                    do
-                    {
+
+                    do {
                         // don't hog folders
                         System.IO.Directory.SetCurrentDirectory(mydocs);
                         Logging.Emit("server waiting..");
@@ -103,19 +111,19 @@ public void Listen(string cachedir)
                         } catch (IOException) {
                             Logging.Warning("error on client pipe");
                             nss.Disconnect();
-                            
+
                         } catch (Exception e) {
                             Logging.Error("server exception {0}", e);
                             Stop();
                         }
                     } while (!quitnow);
                     Logging.Emit("server quitting");
                 }
-            }
-            catch (IOException ex)
-            {
+            } catch (IOException ex) {
                 Logging.Emit("{0}", ex);
                 return;
+            } finally {
+                mtx.ReleaseMutex();
             }
         }
 

diff --git a/CClash/CClashServerClient.cs b/CClash/CClashServerClient.cs
@@ -49,25 +49,17 @@ void Connect()
 
             // start the server, but lets not try to use it here, the next instance can
             try {
-                var pl = System.Diagnostics.Process.GetProcesses();
-                var serverrunning = false;
-                foreach (Process proc in pl) {
-                    if (proc.StartInfo.Arguments.Contains("--cclash-server")) {
-                        serverrunning = true;
-                        break;
-                    }
-                }
-                if (!serverrunning) {
-                    var p = new Process();
-                    p.StartInfo = new ProcessStartInfo(GetType().Assembly.Location, "--cclash-server");
-                    p.StartInfo.UseShellExecute = false;
-                    p.StartInfo.CreateNoWindow = true;
-                    p.StartInfo.Arguments = "--cclash-server";
-                    p.StartInfo.ErrorDialog = false;
-                    p.StartInfo.WorkingDirectory = Environment.CurrentDirectory;
-                    p.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
-                    p.Start();
-                }
+
+                var p = new Process();
+                p.StartInfo = new ProcessStartInfo(GetType().Assembly.Location, "--cclash-server");
+                p.StartInfo.UseShellExecute = false;
+                p.StartInfo.CreateNoWindow = true;
+                p.StartInfo.Arguments = "--cclash-server";
+                p.StartInfo.ErrorDialog = false;
+                p.StartInfo.WorkingDirectory = Environment.CurrentDirectory;
+                p.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
+                p.Start();
+
             } catch (Exception e) {
                 Logging.Emit("error starting cclash server process", e.Message);
             }

diff --git a/cclash.v11.suo b/cclash.v11.suo