// ==++==
// 
//   Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// ==--==
/*============================================================
**
** Class:  SafeFileMappingHandle
**
** <EMAIL>Author: David Gutierrez (Microsoft) </EMAIL>
**
** A wrapper for handle to file mappings, returned by 
** CreateFileMapping and OpenFileMapping.  Used for shared 
** memory.
**
** Date:  July 8, 2002
** 
===========================================================*/

using System;
using System.Security;
using System.Security.Permissions;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;
using Microsoft.Win32;
using Microsoft.Win32.SafeHandles;
using System.Runtime.ConstrainedExecution;
using System.Runtime.Versioning;

namespace Microsoft.Win32.SafeHandles {
    [HostProtectionAttribute(MayLeakOnAbort = true)]
    [SuppressUnmanagedCodeSecurityAttribute]
    internal sealed class SafeFileMappingHandle : SafeHandleZeroOrMinusOneIsInvalid
    { 
        // Note that CreateFileMapping returns 0 on failure.

        // Note that you can pass in -1 for the hFile parameter.
        [SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode=true)]
        internal SafeFileMappingHandle() : base(true) {}
             
        [DllImport(ExternDll.Kernel32, ExactSpelling=true, SetLastError=true)]
        [ResourceExposure(ResourceScope.None)]
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
        private static extern bool CloseHandle(IntPtr handle);

        override protected bool ReleaseHandle()
        {
            return CloseHandle(handle);
        }
    }
}