AipGateway/Experimental.System.Messaging-master/Experimental.System.Messaging/Messaging/Interop/SafeHandles.cs

//------------------------------------------------------------------------------
// <copyright file="IPersistStreamInit.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>                                                                
//------------------------------------------------------------------------------

using Microsoft.Win32.SafeHandles;
using System;

namespace Experimental.System.Messaging.Interop
{
    internal class MessageQueueHandle : SafeHandleZeroOrMinusOneIsInvalid
    {

        public static readonly MessageQueueHandle InvalidHandle = new InvalidMessageQueueHandle();

        MessageQueueHandle() : base(true) { }


        protected override bool ReleaseHandle()
        {
            SafeNativeMethods.MQCloseQueue(this.handle);

            return true;
        }

        public override bool IsInvalid
        {
            get { return base.IsInvalid || IsClosed; }
        }


        // A subclass needed to express InvalidHandle. The reason is that CLR notices that 
        // ReleaseHandle requires a call to MQRT.DLL, and throws in the ctor if MQRT.DLL is not available,
        // even though CTOR ITSELF DOES NOT REQUIRE MQRT.DLL. 
        // We address this by defining a NOOP ReleaseHandle
        sealed class InvalidMessageQueueHandle : MessageQueueHandle
        {

            protected override bool ReleaseHandle()
            {
                return true;
            }
        }
    }


    internal class CursorHandle : SafeHandleZeroOrMinusOneIsInvalid
    {

        public static readonly CursorHandle NullHandle = new InvalidCursorHandle();

        protected CursorHandle() : base(true) { }

        protected override bool ReleaseHandle()
        {
            SafeNativeMethods.MQCloseCursor(this.handle);

            return true;
        }

        public override bool IsInvalid
        {
            get { return base.IsInvalid || IsClosed; }
        }


        // A subclass needed to express InvalidHandle. The reason is that CLR notices that 
        // ReleaseHandle requires a call to MQRT.DLL, and throws in the ctor if MQRT.DLL is not available,
        // even though CTOR ITSELF DOES NOT REQUIRE MQRT.DLL. 
        // We address this by defining a NOOP ReleaseHandle
        sealed class InvalidCursorHandle : CursorHandle
        {

            protected override bool ReleaseHandle()
            {
                return true;
            }
        }
    }


    internal class LocatorHandle : SafeHandleZeroOrMinusOneIsInvalid
    {

        public static readonly LocatorHandle InvalidHandle = new InvalidLocatorHandle();

        protected LocatorHandle() : base(true) { }

        protected override bool ReleaseHandle()
        {
            SafeNativeMethods.MQLocateEnd(this.handle);

            return true;
        }

        public override bool IsInvalid
        {
            get { return base.IsInvalid || IsClosed; }
        }


        // A subclass needed to express InvalidHandle. The reason is that CLR notices that 
        // ReleaseHandle requires a call to MQRT.DLL, and throws in the ctor if MQRT.DLL is not available,
        // even though CTOR ITSELF DOES NOT REQUIRE MQRT.DLL. 
        // We address this by defining a NOOP ReleaseHandle
        sealed class InvalidLocatorHandle : LocatorHandle
        {

            protected override bool ReleaseHandle()
            {
                return true;
            }
        }
    }




    internal sealed class SecurityContextHandle : SafeHandleZeroOrMinusOneIsInvalid
    {

        internal SecurityContextHandle(IntPtr existingHandle)
            : base(true)
        {
            SetHandle(existingHandle);
        }

        protected override bool ReleaseHandle()
        {
            SafeNativeMethods.MQFreeSecurityContext(this.handle);

            return true;
        }

        public override bool IsInvalid
        {
            get { return base.IsInvalid || IsClosed; }
        }
    }
}