[PATCH libdrm 6/9] tests/random: extract test out of xf86drmRandom.c

Emil Velikov emil.l.velikov at gmail.com
Sun Mar 22 15:03:42 PDT 2015


With follow up commits we can clear it up and wire to
make check

Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
---
 tests/Makefile.am |   3 +-
 tests/random.c    | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 xf86drmRandom.c   |  67 ++--------------------------
 3 files changed, 132 insertions(+), 65 deletions(-)
 create mode 100644 tests/random.c

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 392abf5..9b13b2e 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 0000000..6dc8386
--- /dev/null
+++ b/tests/random.c
@@ -0,0 +1,127 @@
+/* xf86drmRandom.c -- "Minimal Standard" PRNG Implementation
+ * Created: Mon Apr 19 08:28:13 1999 by faith at 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 <faith at valinux.com>
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+
+#include "xf86drm.h"
+
+typedef struct RandomState {
+    unsigned long magic;
+    unsigned long a;
+    unsigned long m;
+    unsigned long q;		/* m div a */
+    unsigned long r;		/* m mod a */
+    unsigned long check;
+    unsigned long seed;
+} RandomState;
+
+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;
+}
diff --git a/xf86drmRandom.c b/xf86drmRandom.c
index 94922ad..39f3c52 100644
--- a/xf86drmRandom.c
+++ b/xf86drmRandom.c
@@ -74,23 +74,11 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#define RANDOM_MAIN 0
-
-#if !RANDOM_MAIN
-# include "xf86drm.h"
-#endif
+#include "xf86drm.h"
 
 #define RANDOM_MAGIC 0xfeedbeef
 #define RANDOM_DEBUG 0
 
-#if RANDOM_MAIN
-#define RANDOM_ALLOC malloc
-#define RANDOM_FREE  free
-#else
-#define RANDOM_ALLOC drmMalloc
-#define RANDOM_FREE  drmFree
-#endif
-
 typedef struct RandomState {
     unsigned long magic;
     unsigned long a;
@@ -101,18 +89,11 @@ typedef struct RandomState {
     unsigned long seed;
 } RandomState;
 
-#if RANDOM_MAIN
-extern void          *drmRandomCreate(unsigned long seed);
-extern int           drmRandomDestroy(void *state);
-extern unsigned long drmRandom(void *state);
-extern double        drmRandomDouble(void *state);
-#endif
-
 void *drmRandomCreate(unsigned long seed)
 {
     RandomState  *state;
 
-    state           = RANDOM_ALLOC(sizeof(*state));
+    state           = drmMalloc(sizeof(*state));
     if (!state) return NULL;
     state->magic    = RANDOM_MAGIC;
 #if 0
@@ -140,7 +121,7 @@ void *drmRandomCreate(unsigned long seed)
 
 int drmRandomDestroy(void *state)
 {
-    RANDOM_FREE(state);
+    drmFree(state);
     return 0;
 }
 
@@ -164,45 +145,3 @@ double drmRandomDouble(void *state)
     
     return (double)drmRandom(state)/(double)s->m;
 }
-
-#if RANDOM_MAIN
-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;
-}
-#endif
-- 
2.3.1



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