class/System/System.Threading/Semaphore.cs

   1 //
   2 // System.Threading.Semaphore.cs
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // Copyright (C) 2005 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 #if NET_2_0
  30
  31 using System.Runtime.ConstrainedExecution;
  32 using System.Runtime.InteropServices;
  33 using System.Security.AccessControl;
  34 using System.Runtime.CompilerServices;
  35 using System.IO;
  36
  37 namespace System.Threading {
  38
  39         [ComVisible (false)]
  40         public sealed class Semaphore : WaitHandle {
  41
  42                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  43                 private static extern IntPtr CreateSemaphore_internal (
  44                         int initialCount, int maximumCount, string name,
  45                         out bool createdNew);
  46
  47                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  48                 private static extern int ReleaseSemaphore_internal (
  49                         IntPtr handle, int releaseCount, out bool fail);
  50
  51                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  52                 private static extern IntPtr OpenSemaphore_internal (string name, SemaphoreRights rights, out MonoIOError error);
  53
  54                 private Semaphore (IntPtr handle)
  55                 {
  56                         Handle = handle;
  57                 }
  58
  59                 public Semaphore (int initialCount, int maximumCount)
  60                         : this (initialCount, maximumCount, null)
  61                 {
  62                 }
  63
  64                 public Semaphore (int initialCount, int maximumCount, string name)
  65                 {
  66                         if (initialCount < 0)
  67                                 throw new ArgumentOutOfRangeException ("initialCount", "< 0");
  68                         if (maximumCount < 1)
  69                                 throw new ArgumentOutOfRangeException ("maximumCount", "< 1");
  70                         if (initialCount > maximumCount)
  71                                 throw new ArgumentException ("initialCount > maximumCount");
  72
  73                         bool created;
  74
  75                         Handle = CreateSemaphore_internal (initialCount,
  76                                                            maximumCount, name,
  77                                                            out created);
  78                 }
  79
  80                 public Semaphore (int initialCount, int maximumCount, string name, out bool createdNew)
  81                         : this (initialCount, maximumCount, name, out createdNew, null)
  82                 {
  83                 }
  84
  85                 [MonoTODO ("Does not support access control, semaphoreSecurity is ignored")]
  86                 public Semaphore (int initialCount, int maximumCount, string name, out bool createdNew,
  87                         SemaphoreSecurity semaphoreSecurity)
  88                 {
  89                         if (initialCount < 0)
  90                                 throw new ArgumentOutOfRangeException ("initialCount", "< 0");
  91                         if (maximumCount < 1)
  92                                 throw new ArgumentOutOfRangeException ("maximumCount", "< 1");
  93                         if (initialCount > maximumCount)
  94                                 throw new ArgumentException ("initialCount > maximumCount");
  95
  96                         Handle = CreateSemaphore_internal (initialCount,
  97                                                            maximumCount, name,
  98                                                            out createdNew);
  99                 }
 100
 101                 [MonoTODO]
 102                 public SemaphoreSecurity GetAccessControl ()
 103                 {
 104                         throw new NotImplementedException ();
 105                 }
 106
 107                 [PrePrepareMethod]
 108                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 109                 public int Release ()
 110                 {
 111                         return (Release (1));
 112                 }
 113
 114                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 115                 public int Release (int releaseCount)
 116                 {
 117                         if (releaseCount < 1)
 118                                 throw new ArgumentOutOfRangeException ("releaseCount");
 119
 120                         int ret;
 121                         bool fail;
 122
 123                         ret = ReleaseSemaphore_internal (Handle, releaseCount,
 124                                                          out fail);
 125
 126                         if (fail) {
 127                                 throw new SemaphoreFullException ();
 128                         }
 129
 130                         return (ret);
 131                 }
 132
 133                 [MonoTODO]
 134                 public void SetAccessControl (SemaphoreSecurity semaphoreSecurity)
 135                 {
 136                         if (semaphoreSecurity == null)
 137                                 throw new ArgumentNullException ("semaphoreSecurity");
 138
 139                         throw new NotImplementedException ();
 140                 }
 141
 142                 // static methods
 143
 144                 public static Semaphore OpenExisting (string name)
 145                 {
 146                         return OpenExisting (name, SemaphoreRights.Synchronize | SemaphoreRights.Modify);
 147                 }
 148
 149                 public static Semaphore OpenExisting (string name, SemaphoreRights rights)
 150                 {
 151                         if (name == null)
 152                                 throw new ArgumentNullException ("name");
 153                         if ((name.Length ==0) || (name.Length > 260))
 154                                 throw new ArgumentException ("name", Locale.GetText ("Invalid length [1-260]."));
 155
 156                         MonoIOError error;
 157                         IntPtr handle = OpenSemaphore_internal (name, rights,
 158                                                                 out error);
 159                         if (handle == (IntPtr)null) {
 160                                 if (error == MonoIOError.ERROR_FILE_NOT_FOUND) {
 161                                         throw new WaitHandleCannotBeOpenedException (Locale.GetText ("Named Semaphore handle does not exist: ") + name);
 162                                 } else if (error == MonoIOError.ERROR_ACCESS_DENIED) {
 163                                         throw new UnauthorizedAccessException ();
 164                                 } else {
 165                                         throw new IOException (Locale.GetText ("Win32 IO error: ") + error.ToString ());
 166                                 }
 167                         }
 168
 169                         return(new Semaphore (handle));
 170                 }
 171         }
 172 }
 173
 174 #endif