From f1f4cabd8e8602355630b2b4b5715fc137b4dc71 Mon Sep 17 00:00:00 2001 From: Emil Velikov Date: Sun, 22 Mar 2015 21:38:08 +0000 Subject: tests/random: extract test out of xf86drmRandom.c With follow up commits we can clear it up and wire to make check v2: - Use xf86drmRandom.h for common struct.(Jan) - Add test to .gitignore. Signed-off-by: Emil Velikov Reviewed-by: Jan Vesely --- tests/Makefile.am | 3 +- tests/random.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 120 insertions(+), 1 deletion(-) create mode 100644 tests/random.c (limited to 'tests') diff --git a/tests/Makefile.am b/tests/Makefile.am index 2e0520a7..45a604f2 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -29,7 +29,8 @@ LDADD = $(top_builddir)/libdrm.la check_PROGRAMS = \ dristat \ - drmstat + drmstat \ + random if HAVE_NOUVEAU SUBDIRS += nouveau diff --git a/tests/random.c b/tests/random.c new file mode 100644 index 00000000..db341f9d --- /dev/null +++ b/tests/random.c @@ -0,0 +1,118 @@ +/* xf86drmRandom.c -- "Minimal Standard" PRNG Implementation + * Created: Mon Apr 19 08:28:13 1999 by faith@precisioninsight.com + * + * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. + * All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * Authors: Rickard E. (Rik) Faith + * + * DESCRIPTION + * + * This file contains a simple, straightforward implementation of the Park + * & Miller "Minimal Standard" PRNG [PM88, PMS93], which is a Lehmer + * multiplicative linear congruential generator (MLCG) with a period of + * 2^31-1. + * + * This implementation is intended to provide a reliable, portable PRNG + * that is suitable for testing a hash table implementation and for + * implementing skip lists. + * + * FUTURE ENHANCEMENTS + * + * If initial seeds are not selected randomly, two instances of the PRNG + * can be correlated. [Knuth81, pp. 32-33] describes a shuffling technique + * that can eliminate this problem. + * + * If PRNGs are used for simulation, the period of the current + * implementation may be too short. [LE88] discusses methods of combining + * MLCGs to produce much longer periods, and suggests some alternative + * values for A and M. [LE90 and Sch92] also provide information on + * long-period PRNGs. + * + * REFERENCES + * + * [Knuth81] Donald E. Knuth. The Art of Computer Programming. Volume 2: + * Seminumerical Algorithms. Reading, Massachusetts: Addison-Wesley, 1981. + * + * [LE88] Pierre L'Ecuyer. "Efficient and Portable Combined Random Number + * Generators". CACM 31(6), June 1988, pp. 742-774. + * + * [LE90] Pierre L'Ecuyer. "Random Numbers for Simulation". CACM 33(10, + * October 1990, pp. 85-97. + * + * [PM88] Stephen K. Park and Keith W. Miller. "Random Number Generators: + * Good Ones are Hard to Find". CACM 31(10), October 1988, pp. 1192-1201. + * + * [Sch92] Bruce Schneier. "Pseudo-Ransom Sequence Generator for 32-Bit + * CPUs". Dr. Dobb's Journal 17(2), February 1992, pp. 34, 37-38, 40. + * + * [PMS93] Stephen K. Park, Keith W. Miller, and Paul K. Stockmeyer. In + * "Technical Correspondence: Remarks on Choosing and Implementing Random + * Number Generators". CACM 36(7), July 1993, pp. 105-110. + * + */ + +#include +#include + +#include "xf86drm.h" +#include "xf86drmRandom.h" + +static void check_period(unsigned long seed) +{ + unsigned long count = 0; + unsigned long initial; + void *state; + + state = drmRandomCreate(seed); + initial = drmRandom(state); + ++count; + while (initial != drmRandom(state)) { + if (!++count) break; + } + printf("With seed of %10lu, period = %10lu (0x%08lx)\n", + seed, count, count); + drmRandomDestroy(state); +} + +int main(void) +{ + RandomState *state; + int i; + unsigned long rand; + + state = drmRandomCreate(1); + for (i = 0; i < 10000; i++) { + rand = drmRandom(state); + } + printf("After 10000 iterations: %lu (%lu expected): %s\n", + rand, state->check, + rand - state->check ? "*INCORRECT*" : "CORRECT"); + drmRandomDestroy(state); + + printf("Checking periods...\n"); + check_period(1); + check_period(2); + check_period(31415926); + + return 0; +} -- cgit v1.2.3