Separate XorShift128 PRNG from /dev/urandom and make it generally available.

2026-06-06 16:50:55 +08:00 · 2016-08-20 11:36:02 -06:00
parent a5440fff64
commit 6f833be9d5
5 changed files with 254 additions and 62 deletions
@@ -0,0 +1,98 @@
+/****************************************************************************
+ * include/nuttx/lib/xorshift128.h
+ *
+ *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Author: David S. Alessio
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/* This random number generator is simple, fast and portable.
+ *      Ref:  https://en.wikipedia.org/wiki/Xorshift
+ */
+
+#ifndef __INCLUDE_NUTTX_LIB_XORSHIFT128_H
+#define __INCLUDE_NUTTX_LIB_XORSHIFT128_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: xorshift128_seed
+ *
+ * Description:
+ *   Seed the XorShift128 PRNG
+ *
+ * Input Parameters:
+ *   w, x, y, z:  Values for XorShift128 generation state.
+ *
+ * Returned Value:
+ *   No
+ *
+ ****************************************************************************/
+
+void xorshift128_seed(uint32_t w, uint32_t x, uint32_t y, uint32_t z);
+
+/****************************************************************************
+ * Name: xorshift128
+ *
+ * Description:
+ *   Generate one 32-bit pseudo-random number
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   The generated pseudo-random number
+ *
+ ****************************************************************************/
+
+uint32_t xorshift128(void);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_LIB_XORSHIFT128_H */