System.Security.AccessControl.Privilege.Revert C# (CSharp) Method

        public void Revert()
        {
            int error = 0;

            if (!this.currentThread.Equals(Thread.CurrentThread))
            {
                throw new InvalidOperationException(SR.InvalidOperation_MustBeSameThread);
            }

            if (!this.NeedToRevert)
            {
                return;
            }

            //
            // This code must be eagerly prepared and non-interruptible.
            //

            try
            {
                //
                // The payload is entirely in the finally block
                // This is how we ensure that the code will not be
                // interrupted by catastrophic exceptions
                //
            }
            finally
            {
                bool success = true;

                try
                {
                    //
                    // Only call AdjustTokenPrivileges if we're not going to be reverting to self,
                    // on this Revert, since doing the latter obliterates the thread token anyway
                    //

                    if (this.stateWasChanged &&
                        (this.tlsContents.ReferenceCountValue > 1 ||
                          !this.tlsContents.IsImpersonating))
                    {
                        Interop.Advapi32.LUID_AND_ATTRIBUTES luidAndAttrs = new Interop.Advapi32.LUID_AND_ATTRIBUTES();
                        luidAndAttrs.Luid = this.luid;
                        luidAndAttrs.Attributes = (this.initialState ? Interop.Advapi32.SEPrivileges.SE_PRIVILEGE_ENABLED : Interop.Advapi32.SEPrivileges.SE_PRIVILEGE_DISABLED);

                        Interop.Advapi32.TOKEN_PRIVILEGE newState = new Interop.Advapi32.TOKEN_PRIVILEGE();
                        newState.PrivilegeCount = 1;
                        newState.Privileges[0] = luidAndAttrs;

                        Interop.Advapi32.TOKEN_PRIVILEGE previousState = new Interop.Advapi32.TOKEN_PRIVILEGE();
                        uint previousSize = 0;

                        if (false == Interop.Advapi32.AdjustTokenPrivileges(
                                          this.tlsContents.ThreadHandle,
                                          false,
                                          ref newState,
                                          (uint)Marshal.SizeOf(previousState),
                                          ref previousState,
                                          ref previousSize))
                        {
                            error = Marshal.GetLastWin32Error();
                            success = false;
                        }
                    }
                }
                finally
                {
                    if (success)
                    {
                        this.Reset();
                    }
                }
            }

            if (error == Interop.Errors.ERROR_NOT_ENOUGH_MEMORY)
            {
                throw new OutOfMemoryException();
            }
            else if (error == Interop.Errors.ERROR_ACCESS_DENIED)
            {
                throw new UnauthorizedAccessException();
            }
            else if (error != 0)
            {
                System.Diagnostics.Debug.Assert(false, string.Format(CultureInfo.InvariantCulture, "AdjustTokenPrivileges() failed with unrecognized error code {0}", error));
                throw new InvalidOperationException();
            }
        }
#if false

        public static void RunWithPrivilege(string privilege, bool enabled, PrivilegedHelper helper)
        {
            if (helper == null)
            {
                throw new ArgumentNullException("helper");
            }
            Contract.EndContractBlock();

            Privilege p = new Privilege(privilege);

            try
            {
                if (enabled)
                {
                    p.Enable();
                }
                else
                {
                    p.Disable();
                }

                helper();
            }
            finally
            {
                p.Revert();
            }
        }