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 using System.Runtime.ConstrainedExecution;
  36 using System.Runtime.InteropServices;
  37
  38 namespace System.Threading
  39 {
  40         [ComVisible (true)]
  41         public static class Monitor
  42         {
  43                 // Grabs the mutex on object 'obj', with a maximum
  44                 // wait time 'ms' but doesn't block - if it can't get
  45                 // the lock it returns false, true if it can
  46                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  47                 private extern static bool Monitor_try_enter(object obj, int ms);
  48
  49                 // Enter/Exit are implemented directly as icalls for performance reasons
  50
  51                 // Acquires the mutex on object 'obj'
  52                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  53                 public extern static void Enter(object obj);
  54
  55                 // Releases the mutex on object 'obj'
  56                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
  57                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  58                 public extern static void Exit(object obj);
  59
  60                 // Signals one of potentially many objects waiting on
  61                 // object 'obj'
  62                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  63                 private extern static void Monitor_pulse(object obj);
  64
  65                 // Checks whether object 'obj' is currently synchronised
  66                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  67                 private extern static bool Monitor_test_synchronised(object obj);
  68
  69                 public static void Pulse(object obj) {
  70                         if(obj==null) {
  71                                 throw new ArgumentNullException("obj");
  72                         }
  73                         if(Monitor_test_synchronised(obj)==false) {
  74                                 throw new SynchronizationLockException("Object is not synchronized");
  75                         }
  76
  77                         Monitor_pulse(obj);
  78                 }
  79
  80                 // Signals all of potentially many objects waiting on
  81                 // object 'obj'
  82                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  83                 private extern static void Monitor_pulse_all(object obj);
  84
  85                 public static void PulseAll(object obj) {
  86                         if(obj==null) {
  87                                 throw new ArgumentNullException("obj");
  88                         }
  89                         if(Monitor_test_synchronised(obj)==false) {
  90                                 throw new SynchronizationLockException("Object is not synchronized");
  91                         }
  92
  93                         Monitor_pulse_all(obj);
  94                 }
  95
  96                 public static bool TryEnter (object obj)
  97                 {
  98                         return TryEnter (obj, 0);
  99                 }
 100
 101                 public static bool TryEnter (object obj, int millisecondsTimeout)
 102                 {
 103                         if (obj == null)
 104                                 throw new ArgumentNullException ("obj");
 105
 106                         if (millisecondsTimeout == Timeout.Infinite) {
 107                                 Enter (obj);
 108                                 return true;
 109                         }
 110
 111                         if (millisecondsTimeout < 0)
 112                                 throw new ArgumentException ("negative value for millisecondsTimeout", "millisecondsTimeout");
 113
 114                         return Monitor_try_enter (obj, millisecondsTimeout);
 115                 }
 116
 117                 public static bool TryEnter (object obj, TimeSpan timeout)
 118                 {
 119                         long ms = (long) timeout.TotalMilliseconds;
 120                         if (ms < Timeout.Infinite || ms > Int32.MaxValue)
 121                                 throw new ArgumentOutOfRangeException ("timeout", "timeout out of range");
 122
 123                         return TryEnter (obj, (int) ms);
 124                 }
 125
 126                 // Waits for a signal on object 'obj' with maximum
 127                 // wait time 'ms'. Returns true if the object was
 128                 // signalled, false if it timed out
 129                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 130                 private extern static bool Monitor_wait(object obj, int ms);
 131
 132                 public static bool Wait (object obj)
 133                 {
 134                         return Wait (obj, Timeout.Infinite);
 135                 }
 136
 137                 public static bool Wait (object obj, int millisecondsTimeout)
 138                 {
 139                         if (obj == null)
 140                                 throw new ArgumentNullException ("obj");
 141
 142                         if (millisecondsTimeout < Timeout.Infinite)
 143                                 throw new ArgumentOutOfRangeException ("millisecondsTimeout", "timeout out of range");
 144
 145                         if (!Monitor_test_synchronised (obj))
 146                                 throw new SynchronizationLockException ("Object is not synchronized");
 147
 148                         return Monitor_wait (obj, millisecondsTimeout);
 149                 }
 150
 151                 public static bool Wait (object obj, TimeSpan timeout)
 152                 {
 153                         long ms = (long) timeout.TotalMilliseconds;
 154                         if (ms < Timeout.Infinite || ms > Int32.MaxValue)
 155                                 throw new ArgumentOutOfRangeException ("timeout", "timeout out of range");
 156
 157                         return Wait (obj, (int) ms);
 158                 }
 159
 160                 public static bool Wait(object obj, int millisecondsTimeout, bool exitContext) {
 161                         try {
 162                                 if (exitContext) {
 163 #if MONOTOUCH
 164                                         throw new NotSupportedException ("exitContext == true is not supported");
 165 #else
 166                                         SynchronizationAttribute.ExitContext ();
 167 #endif
 168                                 }
 169                                 return Wait (obj, millisecondsTimeout);
 170                         }
 171                         finally {
 172                                 if (exitContext) SynchronizationAttribute.EnterContext ();
 173                         }
 174                 }
 175
 176                 public static bool Wait(object obj, TimeSpan timeout, bool exitContext) {
 177                         try {
 178                                 if (exitContext) {
 179 #if MONOTOUCH
 180                                         throw new NotSupportedException ("exitContext == true is not supported");
 181 #else
 182                                         SynchronizationAttribute.ExitContext ();
 183 #endif
 184                                 }
 185                                 return Wait (obj, timeout);
 186                         }
 187                         finally {
 188                                 if (exitContext) SynchronizationAttribute.EnterContext ();
 189                         }
 190                 }
 191
 192                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 193                 extern static void try_enter_with_atomic_var (object obj, int millisecondsTimeout, ref bool lockTaken);
 194
 195                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 196                 extern static void enter_with_atomic_var (object obj, ref bool lockTaken);
 197
 198                 // Can't make this an icall since it has the same name as the other Enter method
 199                 [MethodImpl(MethodImplOptions.AggressiveInlining)]
 200                 public static void Enter (object obj, ref bool lockTaken)
 201                 {
 202                         enter_with_atomic_var (obj, ref lockTaken);
 203                 }
 204
 205                 public static void TryEnter (object obj, ref bool lockTaken)
 206                 {
 207                         TryEnter (obj, 0, ref lockTaken);
 208                 }
 209
 210                 public static void TryEnter (object obj, TimeSpan timeout, ref bool lockTaken)
 211                 {
 212                         long ms = (long) timeout.TotalMilliseconds;
 213                         if (ms < Timeout.Infinite || ms > Int32.MaxValue)
 214                                 throw new ArgumentOutOfRangeException ("timeout", "timeout out of range");
 215                         TryEnter (obj, (int)ms, ref lockTaken);
 216                 }
 217
 218                 public static void TryEnter (object obj, int millisecondsTimeout, ref bool lockTaken)
 219                 {
 220                         if (obj == null)
 221                                 throw new ArgumentNullException ("obj");
 222                         if (lockTaken)
 223                                 throw new ArgumentException ("lockTaken");
 224
 225                         if (millisecondsTimeout < 0 && millisecondsTimeout != Timeout.Infinite)
 226                                 throw new ArgumentException ("negative value for millisecondsTimeout", "millisecondsTimeout");
 227
 228                         try_enter_with_atomic_var (obj, millisecondsTimeout, ref lockTaken);
 229                 }
 230
 231
 232                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 233                 extern static bool Monitor_test_owner (object obj);
 234
 235                 public
 236                 static bool IsEntered (object obj)
 237                 {
 238                         return Monitor_test_owner(obj);
 239                 }
 240         }
 241 }