Don't call CFNetworkCopyProxiesForAutoConfigurationScript from more than one thread...

[mono.git] / mcs / class / System / System.Net / MacProxy.cs

diff --git a/mcs/class/System/System.Net/MacProxy.cs b/mcs/class/System/System.Net/MacProxy.cs
index b6300b9428ef694dc74ce8dd6312c8c0fabac24f..1a5e89ec0a36e8571f3750c8f7091ff635d8b5b1 100644 (file)
--- a/mcs/class/System/System.Net/MacProxy.cs
+++ b/mcs/class/System/System.Net/MacProxy.cs
@@ -25,7 +25,9 @@
 // 
 
 using System;
+using System.Collections.Generic;
 using System.Runtime.InteropServices;
+using System.Threading;
 
 namespace System.Net
 {
@@ -606,10 +608,83 @@ namespace System.Net
                public const string CFNetworkLibrary = "/System/Library/Frameworks/CFNetwork.framework/CFNetwork";
 #endif
                
-               [DllImport (CFNetworkLibrary)]
+               [DllImport (CFNetworkLibrary, EntryPoint = "CFNetworkCopyProxiesForAutoConfigurationScript")]
                // CFArrayRef CFNetworkCopyProxiesForAutoConfigurationScript (CFStringRef proxyAutoConfigurationScript, CFURLRef targetURL, CFErrorRef* error);
-               extern static IntPtr CFNetworkCopyProxiesForAutoConfigurationScript (IntPtr proxyAutoConfigurationScript, IntPtr targetURL, out IntPtr error);
-               
+               extern static IntPtr CFNetworkCopyProxiesForAutoConfigurationScriptSequential (IntPtr proxyAutoConfigurationScript, IntPtr targetURL, out IntPtr error);
+
+               class GetProxyData : IDisposable {
+                       public IntPtr script;
+                       public IntPtr targetUri;
+                       public IntPtr error;
+                       public IntPtr result;
+                       public ManualResetEvent evt = new ManualResetEvent (false);
+
+                       public void Dispose ()
+                       {
+                               evt.Close ();
+                       }
+               }
+
+               static object lock_obj = new object ();
+               static Queue<GetProxyData> get_proxy_queue;
+               static AutoResetEvent proxy_event;
+
+               static void CFNetworkCopyProxiesForAutoConfigurationScriptThread ()
+               {
+                       GetProxyData data;
+                       var data_left = true;
+
+                       while (true) {
+                               proxy_event.WaitOne ();
+
+                               do {
+                                       lock (lock_obj) {
+                                               if (get_proxy_queue.Count == 0)
+                                                       break;
+                                               data = get_proxy_queue.Dequeue ();
+                                               data_left = get_proxy_queue.Count > 0;
+                                       }
+
+                                       data.result = CFNetworkCopyProxiesForAutoConfigurationScriptSequential (data.script, data.targetUri, out data.error);
+                                       data.evt.Set ();
+                               } while (data_left);
+                       }
+               }
+
+               static IntPtr CFNetworkCopyProxiesForAutoConfigurationScript (IntPtr proxyAutoConfigurationScript, IntPtr targetURL, out IntPtr error)
+               {
+                       // This method must only be called on only one thread during an application's life time.
+                       // Note that it's not enough to use a lock to make calls sequential across different threads,
+                       // it has to be one thread. Also note that that thread can't be the main thread, because the
+                       // main thread might be blocking waiting for this network request to finish.
+                       // Another possibility would be to use JavaScriptCore to execute this piece of
+                       // javascript ourselves, but unfortunately it's not available before iOS7.
+                       // See bug #7923 comment #21+.
+
+                       using (var data = new GetProxyData ()) {
+                               data.script = proxyAutoConfigurationScript;
+                               data.targetUri = targetURL;
+
+                               lock (lock_obj) {
+                                       if (get_proxy_queue == null) {
+                                               get_proxy_queue = new Queue<GetProxyData> ();
+                                               proxy_event = new AutoResetEvent (false);
+                                               new Thread (CFNetworkCopyProxiesForAutoConfigurationScriptThread) {
+                                                       IsBackground = true,
+                                               }.Start ();
+                                       }
+                                       get_proxy_queue.Enqueue (data);
+                                       proxy_event.Set ();
+                               }
+
+                               data.evt.WaitOne ();
+
+                               error = data.error;
+
+                               return data.result;
+                       }
+               }
+
                static CFArray CopyProxiesForAutoConfigurationScript (IntPtr proxyAutoConfigurationScript, CFUrl targetURL)
                {
                        IntPtr err = IntPtr.Zero;