Semaphore.cs :  » 2.6.4-mono-.net-core » System.Threading » System » Threading » C# / CSharp Open Source

//
// System.Threading.Semaphore.cs
//
// Author:
//  Sebastien Pouliot  <sebastien@ximian.com>
//
// Copyright (C) 2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

#if NET_2_0

using System.Runtime.ConstrainedExecution;
using System.Runtime.InteropServices;
using System.Security.AccessControl;
using System.Runtime.CompilerServices;
using System.IO;

namespace System.Threading{

  [ComVisible (false)]
  public sealed class Semaphore : WaitHandle {

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    private static extern IntPtr CreateSemaphore_internal (
      int initialCount, int maximumCount, string name,
      out bool createdNew);

    [MethodImplAttribute(MethodImplOptions.InternalCall)]
    private static extern int ReleaseSemaphore_internal (
      IntPtr handle, int releaseCount, out bool fail);

    [MethodImplAttribute (MethodImplOptions.InternalCall)]
    private static extern IntPtr OpenSemaphore_internal (string name, SemaphoreRights rights, out MonoIOError error);
    
    private Semaphore (IntPtr handle)
    {
      Handle = handle;
    }
    
    public Semaphore (int initialCount, int maximumCount)
      : this (initialCount, maximumCount, null)
    {
    }

    public Semaphore (int initialCount, int maximumCount, string name)
    {
      if (initialCount < 0)
        throw new ArgumentOutOfRangeException ("initialCount", "< 0");
      if (maximumCount < 1)
        throw new ArgumentOutOfRangeException ("maximumCount", "< 1");
      if (initialCount > maximumCount)
        throw new ArgumentException ("initialCount > maximumCount");

      bool created;
      
      Handle = CreateSemaphore_internal (initialCount,
                 maximumCount, name,
                 out created);
    }

    public Semaphore (int initialCount, int maximumCount, string name, out bool createdNew)
      : this (initialCount, maximumCount, name, out createdNew, null)
    {
    }

    [MonoTODO ("Does not support access control, semaphoreSecurity is ignored")]
    public Semaphore (int initialCount, int maximumCount, string name, out bool createdNew, 
      SemaphoreSecurity semaphoreSecurity)
    {
      if (initialCount < 0)
        throw new ArgumentOutOfRangeException ("initialCount", "< 0");
      if (maximumCount < 1)
        throw new ArgumentOutOfRangeException ("maximumCount", "< 1");
      if (initialCount > maximumCount)
        throw new ArgumentException ("initialCount > maximumCount");

      Handle = CreateSemaphore_internal (initialCount,
                 maximumCount, name,
                 out createdNew);
    }

    [MonoTODO]
    public SemaphoreSecurity GetAccessControl ()
    {
      throw new NotImplementedException ();
    }

    [PrePrepareMethod]
    [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
    public int Release ()
    {
      return (Release (1));
    }

    [ReliabilityContract (Consistency.WillNotCorruptState, Cer.Success)]
    public int Release (int releaseCount)
    {
      if (releaseCount < 1)
        throw new ArgumentOutOfRangeException ("releaseCount");

      int ret;
      bool fail;
      
      ret = ReleaseSemaphore_internal (Handle, releaseCount,
               out fail);

      if (fail) {
        throw new SemaphoreFullException ();
      }

      return (ret);
    }

    [MonoTODO]
    public void SetAccessControl (SemaphoreSecurity semaphoreSecurity)
    {
      if (semaphoreSecurity == null)
        throw new ArgumentNullException ("semaphoreSecurity");

      throw new NotImplementedException ();
    }

    // static methods

    public static Semaphore OpenExisting (string name)
    {
      return OpenExisting (name, SemaphoreRights.Synchronize | SemaphoreRights.Modify);
    }

    public static Semaphore OpenExisting (string name, SemaphoreRights rights)
    {
      if (name == null)
        throw new ArgumentNullException ("name");
      if ((name.Length ==0) || (name.Length > 260))
        throw new ArgumentException ("name", Locale.GetText ("Invalid length [1-260]."));

      MonoIOError error;
      IntPtr handle = OpenSemaphore_internal (name, rights,
                out error);
      if (handle == (IntPtr)null) {
        if (error == MonoIOError.ERROR_FILE_NOT_FOUND) {
          throw new WaitHandleCannotBeOpenedException (Locale.GetText ("Named Semaphore handle does not exist: ") + name);
        } else if (error == MonoIOError.ERROR_ACCESS_DENIED) {
          throw new UnauthorizedAccessException ();
        } else {
          throw new IOException (Locale.GetText ("Win32 IO error: ") + error.ToString ());
        }
      }
      
      return(new Semaphore (handle));
    }
  }
}

#endif