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 #endif
  39
  40 namespace System.Threading
  41 {
  42         public sealed class Monitor
  43         {
  44                 private Monitor () {}
  45
  46                 // Grabs the mutex on object 'obj', with a maximum
  47                 // wait time 'ms' but doesn't block - if it can't get
  48                 // the lock it returns false, true if it can
  49                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  50                 private extern static bool Monitor_try_enter(object obj, int ms);
  51
  52                 public static void Enter(object obj) {
  53                         if(obj==null) {
  54                                 throw new ArgumentNullException("obj");
  55                         }
  56                         //if(obj.GetType().IsValueType==true) {
  57                         //      throw new ArgumentException("Value type");
  58                         //}
  59
  60                         Monitor_try_enter(obj, Timeout.Infinite);
  61                 }
  62
  63                 // Releases the mutex on object 'obj'
  64                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  65                 private extern static void Monitor_exit(object obj);
  66
  67 #if NET_2_0
  68                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
  69 #endif
  70                 public static void Exit(object obj) {
  71                         if(obj==null) {
  72                                 throw new ArgumentNullException("obj");
  73                         }
  74                         //if(obj.GetType().IsValueType==true) {
  75                         //      throw new ArgumentException("Value type");
  76                         //}
  77
  78                         Monitor_exit(obj);
  79                 }
  80
  81                 // Signals one of potentially many objects waiting on
  82                 // object 'obj'
  83                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  84                 private extern static void Monitor_pulse(object obj);
  85
  86                 // Checks whether object 'obj' is currently synchronised
  87                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  88                 private extern static bool Monitor_test_synchronised(object obj);
  89
  90                 public static void Pulse(object obj) {
  91                         if(obj==null) {
  92                                 throw new ArgumentNullException("obj");
  93                         }
  94                         if(Monitor_test_synchronised(obj)==false) {
  95                                 throw new SynchronizationLockException("Object is not synchronized");
  96                         }
  97
  98                         Monitor_pulse(obj);
  99                 }
 100
 101                 // Signals all of potentially many objects waiting on
 102                 // object 'obj'
 103                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 104                 private extern static void Monitor_pulse_all(object obj);
 105
 106                 public static void PulseAll(object obj) {
 107                         if(obj==null) {
 108                                 throw new ArgumentNullException("obj");
 109                         }
 110                         if(Monitor_test_synchronised(obj)==false) {
 111                                 throw new SynchronizationLockException("Object is not synchronized");
 112                         }
 113
 114                         Monitor_pulse_all(obj);
 115                 }
 116
 117                 public static bool TryEnter(object obj) {
 118                         if(obj==null) {
 119                                 throw new ArgumentNullException("obj");
 120                         }
 121                         //if(obj.GetType().IsValueType==true) {
 122                         //      throw new ArgumentException("Value type");
 123                         //}
 124
 125                         return(Monitor_try_enter(obj, 0));
 126                 }
 127
 128                 public static bool TryEnter(object obj, int millisecondsTimeout) {
 129                         if(obj==null) {
 130                                 throw new ArgumentNullException("obj");
 131                         }
 132                         //if(obj.GetType().IsValueType==true) {
 133                         //      throw new ArgumentException("Value type");
 134                         //}
 135
 136                         // LAMESPEC: should throw an exception when ms<0, but
 137                         // Timeout.Infinite is -1
 138                         if(millisecondsTimeout == Timeout.Infinite) {
 139                                 Enter(obj);
 140                                 return(true);
 141                         }
 142
 143                         if(millisecondsTimeout<0) {
 144                                 throw new ArgumentException("millisecondsTimeout", "negative value for millisecondsTimeout");
 145                         }
 146
 147                         return(Monitor_try_enter(obj, millisecondsTimeout));
 148                 }
 149
 150                 public static bool TryEnter(object obj, TimeSpan timeout) {
 151                         if(obj==null) {
 152                                 throw new ArgumentNullException("obj");
 153                         }
 154                         //if(obj.GetType().IsValueType==true) {
 155                         //      throw new ArgumentException("Value type");
 156                         //}
 157
 158                         // LAMESPEC: should throw an exception when ms<0, but
 159                         // Timeout.Infinite is -1
 160                         int ms=Convert.ToInt32(timeout.TotalMilliseconds);
 161
 162                         if(ms == Timeout.Infinite) {
 163                                 Enter(obj);
 164                                 return(true);
 165                         }
 166
 167                         if(ms < 0 || ms > Int32.MaxValue) {
 168                                 throw new ArgumentOutOfRangeException("timeout", "timeout out of range");
 169                         }
 170
 171                         return(Monitor_try_enter(obj, ms));
 172                 }
 173
 174                 // Waits for a signal on object 'obj' with maximum
 175                 // wait time 'ms'. Returns true if the object was
 176                 // signalled, false if it timed out
 177                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 178                 private extern static bool Monitor_wait(object obj, int ms);
 179
 180                 public static bool Wait(object obj) {
 181                         if(obj==null) {
 182                                 throw new ArgumentNullException("obj");
 183                         }
 184                         if(Monitor_test_synchronised(obj)==false) {
 185                                 throw new SynchronizationLockException("Object is not synchronized");
 186                         }
 187
 188                         return(Monitor_wait(obj, Timeout.Infinite));
 189                 }
 190
 191                 public static bool Wait(object obj, int millisecondsTimeout) {
 192                         if(obj==null) {
 193                                 throw new ArgumentNullException("obj");
 194                         }
 195                         if(Monitor_test_synchronised(obj)==false) {
 196                                 throw new SynchronizationLockException("Object is not synchronized");
 197                         }
 198                         if (millisecondsTimeout < 0 && millisecondsTimeout != Timeout.Infinite)
 199                                 throw new ArgumentOutOfRangeException ("millisecondsTimeout", "timeout out of range");
 200
 201                         return(Monitor_wait(obj, millisecondsTimeout));
 202                 }
 203
 204                 public static bool Wait(object obj, TimeSpan timeout) {
 205                         if(obj==null) {
 206                                 throw new ArgumentNullException("obj");
 207                         }
 208                         // LAMESPEC: says to throw ArgumentException too
 209                         int ms=Convert.ToInt32(timeout.TotalMilliseconds);
 210
 211                         if((ms < 0 && ms != Timeout.Infinite) || ms > Int32.MaxValue) {
 212                                 throw new ArgumentOutOfRangeException("timeout", "timeout out of range");
 213                         }
 214                         if(Monitor_test_synchronised(obj)==false) {
 215                                 throw new SynchronizationLockException("Object is not synchronized");
 216                         }
 217
 218                         return(Monitor_wait(obj, ms));
 219                 }
 220
 221                 public static bool Wait(object obj, int millisecondsTimeout, bool exitContext) {
 222                         try {
 223                                 if (exitContext) SynchronizationAttribute.ExitContext ();
 224                                 return Wait (obj, millisecondsTimeout);
 225                         }
 226                         finally {
 227                                 if (exitContext) SynchronizationAttribute.EnterContext ();
 228                         }
 229                 }
 230
 231                 public static bool Wait(object obj, TimeSpan timeout, bool exitContext) {
 232                         try {
 233                                 if (exitContext) SynchronizationAttribute.ExitContext ();
 234                                 return Wait (obj, timeout);
 235                         }
 236                         finally {
 237                                 if (exitContext) SynchronizationAttribute.EnterContext ();
 238                         }
 239                 }
 240         }
 241 }