System.Text.RegularExpressions.SharedReference.Cache C# (CSharp) Method

        internal void Cache(Object obj) {
            if (0 == Interlocked.Exchange(ref _locked, 1)) {
                _ref.Target = obj;
                _locked = 0;
            }
        }
    }

        /// <summary>
        /// Replaces all occurrences of the previously defined pattern with the
        /// <paramref name="replacement"/> pattern, starting at the character position
        /// <paramref name="startat"/>.
        /// </summary>
        public string Replace(string input, string replacement, int count, int startat)
        {
            if (input == null)
                throw new ArgumentNullException(nameof(input));

            if (replacement == null)
                throw new ArgumentNullException(nameof(replacement));

            // a little code to grab a cached parsed replacement object
            RegexReplacement repl = (RegexReplacement)_replref.Get();

            if (repl == null || !repl.Pattern.Equals(replacement))
            {
                repl = RegexParser.ParseReplacement(replacement, caps, capsize, capnames, roptions);
                _replref.Cache(repl);
            }

            return repl.Replace(this, input, count, startat);
        }