namespace System.Diagnostics { internal sealed class RandomNumberGenerator { [ThreadStatic] private static RandomNumberGenerator t_random; private ulong _s0; private ulong _s1; private ulong _s2; private ulong _s3; public static RandomNumberGenerator Current { get { if (t_random == null) t_random = new RandomNumberGenerator(); return t_random; } } public unsafe RandomNumberGenerator() { do { Guid guid = Guid.NewGuid(); Guid guid2 = Guid.NewGuid(); ulong* ptr = (ulong*)(&guid); ulong* ptr2 = (ulong*)(&guid2); _s0 = *ptr; _s1 = ptr[1]; _s2 = *ptr2; _s3 = ptr2[1]; _s0 = (ulong)((long)(_s0 & 1152921504606846975) | ((long)_s1 & -1152921504606846976)); _s2 = (ulong)((long)(_s2 & 1152921504606846975) | ((long)_s3 & -1152921504606846976)); _s1 = (ulong)(((long)_s1 & -193) | (long)(_s0 & 192)); _s3 = (ulong)(((long)_s3 & -193) | (long)(_s2 & 192)); } while ((_s0 | _s1 | _s2 | _s3) == 0); } private ulong Rol64(ulong x, int k) { return (x << k) | (x >> 64 - k); } public long Next() { ulong result = Rol64(_s1 * 5, 7) * 9; ulong num = _s1 << 17; _s2 ^= _s0; _s3 ^= _s1; _s1 ^= _s2; _s0 ^= _s3; _s2 ^= num; _s3 = Rol64(_s3, 45); return (long)result; } } }