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

   1 //
   2 // System.Threading.Monitor.cs
   3 //
   4 // Author:
   5 //   Dick Porter (dick@ximian.com)
   6 //
   7 // (C) Ximian, Inc.  http://www.ximian.com
   8 //
   9
  10 //
  11 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.Runtime.CompilerServices;
  34 using System.Runtime.Remoting.Contexts;
  35
  36 #if NET_2_0
  37 using System.Runtime.ConstrainedExecution;
  38 using System.Runtime.InteropServices;
  39 #endif
  40
  41 namespace System.Threading
  42 {
  43 #if NET_2_0
  44         [ComVisible (true)]
  45         public static class Monitor
  46         {
  47 #else
  48         public sealed class Monitor
  49         {
  50                 private Monitor () {}
  51 #endif
  52
  53                 // Grabs the mutex on object 'obj', with a maximum
  54                 // wait time 'ms' but doesn't block - if it can't get
  55                 // the lock it returns false, true if it can
  56                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  57                 private extern static bool Monitor_try_enter(object obj, int ms);
  58
  59                 // Enter/Exit are implemented directly as icalls for performance reasons
  60
  61                 // Acquires the mutex on object 'obj'
  62                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  63                 public extern static void Enter(object obj);
  64
  65                 // Releases the mutex on object 'obj'
  66 #if NET_2_0
  67                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
  68 #endif
  69                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  70                 public extern static void Exit(object obj);
  71
  72                 // Signals one of potentially many objects waiting on
  73                 // object 'obj'
  74                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  75                 private extern static void Monitor_pulse(object obj);
  76
  77                 // Checks whether object 'obj' is currently synchronised
  78                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  79                 private extern static bool Monitor_test_synchronised(object obj);
  80
  81                 public static void Pulse(object obj) {
  82                         if(obj==null) {
  83                                 throw new ArgumentNullException("obj");
  84                         }
  85                         if(Monitor_test_synchronised(obj)==false) {
  86                                 throw new SynchronizationLockException("Object is not synchronized");
  87                         }
  88
  89                         Monitor_pulse(obj);
  90                 }
  91
  92                 // Signals all of potentially many objects waiting on
  93                 // object 'obj'
  94                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  95                 private extern static void Monitor_pulse_all(object obj);
  96
  97                 public static void PulseAll(object obj) {
  98                         if(obj==null) {
  99                                 throw new ArgumentNullException("obj");
 100                         }
 101                         if(Monitor_test_synchronised(obj)==false) {
 102                                 throw new SynchronizationLockException("Object is not synchronized");
 103                         }
 104
 105                         Monitor_pulse_all(obj);
 106                 }
 107
 108                 public static bool TryEnter(object obj) {
 109                         if(obj==null) {
 110                                 throw new ArgumentNullException("obj");
 111                         }
 112                         //if(obj.GetType().IsValueType==true) {
 113                         //      throw new ArgumentException("Value type");
 114                         //}
 115
 116                         return(Monitor_try_enter(obj, 0));
 117                 }
 118
 119                 public static bool TryEnter(object obj, int millisecondsTimeout) {
 120                         if(obj==null) {
 121                                 throw new ArgumentNullException("obj");
 122                         }
 123                         //if(obj.GetType().IsValueType==true) {
 124                         //      throw new ArgumentException("Value type");
 125                         //}
 126
 127                         // LAMESPEC: should throw an exception when ms<0, but
 128                         // Timeout.Infinite is -1
 129                         if(millisecondsTimeout == Timeout.Infinite) {
 130                                 Enter(obj);
 131                                 return(true);
 132                         }
 133
 134                         if(millisecondsTimeout<0) {
 135                                 throw new ArgumentException("millisecondsTimeout", "negative value for millisecondsTimeout");
 136                         }
 137
 138                         return(Monitor_try_enter(obj, millisecondsTimeout));
 139                 }
 140
 141                 public static bool TryEnter(object obj, TimeSpan timeout) {
 142                         if(obj==null) {
 143                                 throw new ArgumentNullException("obj");
 144                         }
 145                         //if(obj.GetType().IsValueType==true) {
 146                         //      throw new ArgumentException("Value type");
 147                         //}
 148
 149                         // LAMESPEC: should throw an exception when ms<0, but
 150                         // Timeout.Infinite is -1
 151                         int ms=Convert.ToInt32(timeout.TotalMilliseconds);
 152
 153                         if(ms == Timeout.Infinite) {
 154                                 Enter(obj);
 155                                 return(true);
 156                         }
 157
 158                         if(ms < 0 || ms > Int32.MaxValue) {
 159                                 throw new ArgumentOutOfRangeException("timeout", "timeout out of range");
 160                         }
 161
 162                         return(Monitor_try_enter(obj, ms));
 163                 }
 164
 165                 // Waits for a signal on object 'obj' with maximum
 166                 // wait time 'ms'. Returns true if the object was
 167                 // signalled, false if it timed out
 168                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 169                 private extern static bool Monitor_wait(object obj, int ms);
 170
 171                 public static bool Wait(object obj) {
 172                         if(obj==null) {
 173                                 throw new ArgumentNullException("obj");
 174                         }
 175                         if(Monitor_test_synchronised(obj)==false) {
 176                                 throw new SynchronizationLockException("Object is not synchronized");
 177                         }
 178
 179                         return(Monitor_wait(obj, Timeout.Infinite));
 180                 }
 181
 182                 public static bool Wait(object obj, int millisecondsTimeout) {
 183                         if(obj==null) {
 184                                 throw new ArgumentNullException("obj");
 185                         }
 186                         if(Monitor_test_synchronised(obj)==false) {
 187                                 throw new SynchronizationLockException("Object is not synchronized");
 188                         }
 189                         if (millisecondsTimeout < 0 && millisecondsTimeout != Timeout.Infinite)
 190                                 throw new ArgumentOutOfRangeException ("millisecondsTimeout", "timeout out of range");
 191
 192                         return(Monitor_wait(obj, millisecondsTimeout));
 193                 }
 194
 195                 public static bool Wait(object obj, TimeSpan timeout) {
 196                         if(obj==null) {
 197                                 throw new ArgumentNullException("obj");
 198                         }
 199                         // LAMESPEC: says to throw ArgumentException too
 200                         int ms=Convert.ToInt32(timeout.TotalMilliseconds);
 201
 202                         if((ms < 0 && ms != Timeout.Infinite) || ms > Int32.MaxValue) {
 203                                 throw new ArgumentOutOfRangeException("timeout", "timeout out of range");
 204                         }
 205                         if(Monitor_test_synchronised(obj)==false) {
 206                                 throw new SynchronizationLockException("Object is not synchronized");
 207                         }
 208
 209                         return(Monitor_wait(obj, ms));
 210                 }
 211
 212                 public static bool Wait(object obj, int millisecondsTimeout, bool exitContext) {
 213                         try {
 214                                 if (exitContext) SynchronizationAttribute.ExitContext ();
 215                                 return Wait (obj, millisecondsTimeout);
 216                         }
 217                         finally {
 218                                 if (exitContext) SynchronizationAttribute.EnterContext ();
 219                         }
 220                 }
 221
 222                 public static bool Wait(object obj, TimeSpan timeout, bool exitContext) {
 223                         try {
 224                                 if (exitContext) SynchronizationAttribute.ExitContext ();
 225                                 return Wait (obj, timeout);
 226                         }
 227                         finally {
 228                                 if (exitContext) SynchronizationAttribute.EnterContext ();
 229                         }
 230                 }
 231         }
 232 }