System.Text.RegularExpressions.RegexRunner.StartTimeoutWatch C# (CSharp) Method

        private void StartTimeoutWatch()
        {
            if (_ignoreTimeout)
                return;

            _timeoutChecksToSkip = TimeoutCheckFrequency;

            // We are using Environment.TickCount and not Timewatch for performance reasons.
            // Environment.TickCount is an int that cycles. We intentionally let timeoutOccursAt
            // overflow it will still stay ahead of Environment.TickCount for comparisons made
            // in DoCheckTimeout():
            unchecked
            {
                _timeoutOccursAt = Environment.TickCount + _timeout;
            }
        }