mcs/class/corlib/System.Threading/ExecutionContext.cs

   1 //
   2 // System.Threading.ExecutionContext.cs
   3 //
   4 // Authors:
   5 //      Lluis Sanchez (lluis@novell.com)
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System.Runtime.InteropServices;
  31 using System.Runtime.Serialization;
  32 using System.Security;
  33 using System.Security.Permissions;
  34 using System.Runtime.Remoting.Messaging;
  35
  36 namespace System.Threading {
  37         [Serializable]
  38         public sealed class ExecutionContext : ISerializable
  39 #if NET_4_0
  40                 , IDisposable
  41 #endif
  42         {
  43                 private SecurityContext _sc;
  44                 private LogicalCallContext _lcc;
  45                 private bool _suppressFlow;
  46                 private bool _capture;
  47
  48                 internal ExecutionContext ()
  49                 {
  50                 }
  51
  52                 internal ExecutionContext (ExecutionContext ec)
  53                 {
  54                         if (ec._sc != null)
  55                                 _sc = new SecurityContext (ec._sc);
  56                         _suppressFlow = ec._suppressFlow;
  57                         _capture = true;
  58                 }
  59
  60                 [MonoTODO]
  61                 internal ExecutionContext (SerializationInfo info, StreamingContext context)
  62                 {
  63                         throw new NotImplementedException ();
  64                 }
  65
  66                 public static ExecutionContext Capture ()
  67                 {
  68                         return Capture (true);
  69                 }
  70
  71                 internal static ExecutionContext Capture (bool captureSyncContext)
  72                 {
  73                         ExecutionContext ec = Thread.CurrentThread.ExecutionContext;
  74                         if (ec.FlowSuppressed)
  75                                 return null;
  76
  77                         ExecutionContext capture = new ExecutionContext (ec);
  78                         if (SecurityManager.SecurityEnabled)
  79                                 capture.SecurityContext = SecurityContext.Capture ();
  80 #if !MONOTOUCH
  81                         capture.LogicalCallContext = CallContext.CreateLogicalCallContext (false);
  82 #endif
  83                         return capture;
  84                 }
  85
  86                 public ExecutionContext CreateCopy ()
  87                 {
  88                         if (!_capture)
  89                                 throw new InvalidOperationException ();
  90
  91                         return new ExecutionContext (this);
  92                 }
  93
  94 #if NET_4_0
  95                 public void Dispose ()
  96                 {
  97                         if (_sc != null)
  98                                 _sc.Dispose ();
  99                 }
 100 #endif
 101
 102                 [MonoTODO]
 103                 [ReflectionPermission (SecurityAction.Demand, MemberAccess = true)]
 104                 public void GetObjectData (SerializationInfo info, StreamingContext context)
 105                 {
 106                         if (info == null)
 107                                 throw new ArgumentNullException ("info");
 108                         throw new NotImplementedException ();
 109                 }
 110
 111                 // internal stuff
 112
 113                 internal LogicalCallContext LogicalCallContext {
 114                         get {
 115                                 if (_lcc == null)
 116                                         return new LogicalCallContext ();
 117                                 return _lcc;
 118                         }
 119                         set {
 120                                 _lcc = value;
 121                         }
 122                 }
 123
 124                 internal SecurityContext SecurityContext {
 125                         get {
 126                                 if (_sc == null)
 127                                         _sc = new SecurityContext ();
 128                                 return _sc;
 129                         }
 130                         set { _sc = value; }
 131                 }
 132                 internal bool FlowSuppressed {
 133                         get { return _suppressFlow; }
 134                         set { _suppressFlow = value; }
 135                 }
 136
 137                 // Note: Previous to version 2.0 only the CompressedStack and (sometimes!) the WindowsIdentity
 138                 // were propagated to new threads. This is why ExecutionContext is internal in before NET_2_0.
 139                 // It also means that all newer context classes should be here (i.e. inside the #if NET_2_0).
 140
 141                 public static bool IsFlowSuppressed ()
 142                 {
 143                         return Thread.CurrentThread.ExecutionContext.FlowSuppressed;
 144                 }
 145
 146                 public static void RestoreFlow ()
 147                 {
 148                         ExecutionContext ec = Thread.CurrentThread.ExecutionContext;
 149                         if (!ec.FlowSuppressed)
 150                                 throw new InvalidOperationException ();
 151
 152                         ec.FlowSuppressed = false;
 153                 }
 154
 155                 [MonoTODO ("only the SecurityContext is considered")]
 156                 [SecurityPermission (SecurityAction.LinkDemand, Infrastructure = true)]
 157                 public static void Run (ExecutionContext executionContext, ContextCallback callback, object state)
 158                 {
 159                         if (executionContext == null) {
 160                                 throw new InvalidOperationException (Locale.GetText (
 161                                         "Null ExecutionContext"));
 162                         }
 163
 164                         // FIXME: supporting more than one context should be done with executionContextSwitcher
 165                         // and will requires a rewrite of this method
 166                         var callContextCallBack = new ContextCallback (new Action<object> ((ostate) => {
 167                                 var originalCallContext = CallContext.CreateLogicalCallContext (true);
 168                                 try {
 169                                         CallContext.SetCurrentCallContext (executionContext.LogicalCallContext);
 170                                         callback (ostate);
 171                                 } finally {
 172                                         CallContext.SetCurrentCallContext (originalCallContext);
 173                                 }
 174                         }));
 175                         SecurityContext.Run (executionContext.SecurityContext, callContextCallBack, state);
 176                 }
 177
 178                 public static AsyncFlowControl SuppressFlow ()
 179                 {
 180                         Thread t = Thread.CurrentThread;
 181                         t.ExecutionContext.FlowSuppressed = true;
 182                         return new AsyncFlowControl (t, AsyncFlowControlType.Execution);
 183                 }
 184         }
 185 }