mcs/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 using System.Runtime.ConstrainedExecution;
  30 using System.Runtime.InteropServices;
  31 using System.Security.AccessControl;
  32 using System.Runtime.CompilerServices;
  33 using System.IO;
  34
  35 namespace System.Threading {
  36
  37         [ComVisible (false)]
  38         public sealed class Semaphore : WaitHandle {
  39
  40                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  41                 private static extern IntPtr CreateSemaphore_internal (
  42                         int initialCount, int maximumCount, string name,
  43                         out bool createdNew);
  44
  45                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  46                 private static extern int ReleaseSemaphore_internal (
  47                         IntPtr handle, int releaseCount, out bool fail);
  48
  49                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  50                 private static extern IntPtr OpenSemaphore_internal (string name, SemaphoreRights rights, out MonoIOError error);
  51
  52                 private Semaphore (IntPtr handle)
  53                 {
  54                         Handle = handle;
  55                 }
  56
  57                 public Semaphore (int initialCount, int maximumCount)
  58                         : this (initialCount, maximumCount, null)
  59                 {
  60                 }
  61
  62                 public Semaphore (int initialCount, int maximumCount, string name)
  63                 {
  64                         if (initialCount < 0)
  65                                 throw new ArgumentOutOfRangeException ("initialCount", "< 0");
  66                         if (maximumCount < 1)
  67                                 throw new ArgumentOutOfRangeException ("maximumCount", "< 1");
  68                         if (initialCount > maximumCount)
  69                                 throw new ArgumentException ("initialCount > maximumCount");
  70
  71                         bool created;
  72
  73                         Handle = CreateSemaphore_internal (initialCount,
  74                                                            maximumCount, name,
  75                                                            out created);
  76                 }
  77
  78                 public Semaphore (int initialCount, int maximumCount, string name, out bool createdNew)
  79                         : this (initialCount, maximumCount, name, out createdNew, null)
  80                 {
  81                 }
  82
  83                 [MonoTODO ("Does not support access control, semaphoreSecurity is ignored")]
  84                 public Semaphore (int initialCount, int maximumCount, string name, out bool createdNew,
  85                         SemaphoreSecurity semaphoreSecurity)
  86                 {
  87                         if (initialCount < 0)
  88                                 throw new ArgumentOutOfRangeException ("initialCount", "< 0");
  89                         if (maximumCount < 1)
  90                                 throw new ArgumentOutOfRangeException ("maximumCount", "< 1");
  91                         if (initialCount > maximumCount)
  92                                 throw new ArgumentException ("initialCount > maximumCount");
  93
  94                         Handle = CreateSemaphore_internal (initialCount,
  95                                                            maximumCount, name,
  96                                                            out createdNew);
  97                 }
  98
  99                 [MonoTODO]
 100                 public SemaphoreSecurity GetAccessControl ()
 101                 {
 102                         throw new NotImplementedException ();
 103                 }
 104
 105                 [PrePrepareMethod]
 106                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 107                 public int Release ()
 108                 {
 109                         return (Release (1));
 110                 }
 111
 112                 [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
 113                 public int Release (int releaseCount)
 114                 {
 115                         if (releaseCount < 1)
 116                                 throw new ArgumentOutOfRangeException ("releaseCount");
 117
 118                         int ret;
 119                         bool fail;
 120
 121                         ret = ReleaseSemaphore_internal (Handle, releaseCount,
 122                                                          out fail);
 123
 124                         if (fail) {
 125                                 throw new SemaphoreFullException ();
 126                         }
 127
 128                         return (ret);
 129                 }
 130
 131                 [MonoTODO]
 132                 public void SetAccessControl (SemaphoreSecurity semaphoreSecurity)
 133                 {
 134                         if (semaphoreSecurity == null)
 135                                 throw new ArgumentNullException ("semaphoreSecurity");
 136
 137                         throw new NotImplementedException ();
 138                 }
 139
 140                 // static methods
 141
 142                 public static Semaphore OpenExisting (string name)
 143                 {
 144                         return OpenExisting (name, SemaphoreRights.Synchronize | SemaphoreRights.Modify);
 145                 }
 146
 147                 public static Semaphore OpenExisting (string name, SemaphoreRights rights)
 148                 {
 149                         if (name == null)
 150                                 throw new ArgumentNullException ("name");
 151                         if ((name.Length ==0) || (name.Length > 260))
 152                                 throw new ArgumentException ("name", Locale.GetText ("Invalid length [1-260]."));
 153
 154                         MonoIOError error;
 155                         IntPtr handle = OpenSemaphore_internal (name, rights,
 156                                                                 out error);
 157                         if (handle == (IntPtr)null) {
 158                                 if (error == MonoIOError.ERROR_FILE_NOT_FOUND) {
 159                                         throw new WaitHandleCannotBeOpenedException (Locale.GetText ("Named Semaphore handle does not exist: ") + name);
 160                                 } else if (error == MonoIOError.ERROR_ACCESS_DENIED) {
 161                                         throw new UnauthorizedAccessException ();
 162                                 } else {
 163                                         throw new IOException (Locale.GetText ("Win32 IO error: ") + error.ToString ());
 164                                 }
 165                         }
 166
 167                         return(new Semaphore (handle));
 168                 }
 169         }
 170 }
 171