lib/rand: fix bug with non uint64_t aligned random buffer fill

[fio.git] / lib / rand.c

diff --git a/lib/rand.c b/lib/rand.c
index 06812823994d45cfe744351095af015d5858fbae..32aec208b6c6fc6a01f1cd1ed1301b157286638a 100644 (file)
--- a/lib/rand.c
+++ b/lib/rand.c
@@ -33,51 +33,164 @@
 
 */
 
+#include <string.h>
+#include <assert.h>
 #include "rand.h"
 #include "../hash.h"
 
-struct frand_state __fio_rand_state;
-
 static inline int __seed(unsigned int x, unsigned int m)
 {
        return (x < m) ? x + m : x;
 }
 
+static void __init_rand(struct frand_state *state, unsigned int seed)
+{
+       int cranks = 6;
+
+#define LCG(x, seed)  ((x) * 69069 ^ (seed))
+
+       state->s1 = __seed(LCG((2^31) + (2^17) + (2^7), seed), 1);
+       state->s2 = __seed(LCG(state->s1, seed), 7);
+       state->s3 = __seed(LCG(state->s2, seed), 15);
+
+       while (cranks--)
+               __rand(state);
+}
+
 void init_rand(struct frand_state *state)
 {
-#define LCG(x)  ((x) * 69069)   /* super-duper LCG */
-
-       state->s1 = __seed(LCG((2^31) + (2^17) + (2^7)), 1);
-       state->s2 = __seed(LCG(state->s1), 7);
-       state->s3 = __seed(LCG(state->s2), 15);
-
-       __rand(state);
-       __rand(state);
-       __rand(state);
-       __rand(state);
-       __rand(state);
-       __rand(state);
+       __init_rand(state, 1);
 }
 
-void __fill_random_buf(void *buf, unsigned int len, unsigned long seed)
+void init_rand_seed(struct frand_state *state, unsigned int seed)
 {
-       long *ptr = buf;
+       __init_rand(state, seed);
+}
 
-       while ((void *) ptr - buf < len) {
-               *ptr = seed;
-               ptr++;
+void __fill_random_buf(void *buf, unsigned int len, unsigned long seed)
+{
+       void *ptr = buf;
+
+       while (len) {
+               if (len >= sizeof(int64_t)) {
+                       *((int64_t *) ptr) = seed;
+                       ptr += sizeof(int64_t);
+                       len -= sizeof(int64_t);
+               } else if (len >= sizeof(int32_t)) {
+                       *((int32_t *) ptr) = seed;
+                       ptr += sizeof(int32_t);
+                       len -= sizeof(int32_t);
+               } else if (len >= sizeof(int16_t)) {
+                       *((int16_t *) ptr) = seed;
+                       ptr += sizeof(int16_t);
+                       len -= sizeof(int16_t);
+               } else {
+                       *((int8_t *) ptr) = seed;
+                       ptr += sizeof(int8_t);
+                       len -= sizeof(int8_t);
+               }
                seed *= GOLDEN_RATIO_PRIME;
                seed >>= 3;
        }
 }
 
-unsigned long fill_random_buf(void *buf, unsigned int len)
+unsigned long fill_random_buf(struct frand_state *fs, void *buf,
+                             unsigned int len)
 {
-       unsigned long r = __rand(&__fio_rand_state);
+       unsigned long r = __rand(fs);
 
        if (sizeof(int) != sizeof(long *))
-               r *= (unsigned long) __rand(&__fio_rand_state);
+               r *= (unsigned long) __rand(fs);
 
        __fill_random_buf(buf, len, r);
        return r;
 }
+
+void fill_pattern(void *p, unsigned int len, char *pattern,
+                 unsigned int pattern_bytes)
+{
+       switch (pattern_bytes) {
+       case 0:
+               assert(0);
+               break;
+       case 1:
+               memset(p, pattern[0], len);
+               break;
+       default: {
+               unsigned int i = 0, size = 0;
+               unsigned char *b = p;
+
+               while (i < len) {
+                       size = pattern_bytes;
+                       if (size > (len - i))
+                               size = len - i;
+                       memcpy(b+i, pattern, size);
+                       i += size;
+               }
+               break;
+               }
+       }
+}
+
+void __fill_random_buf_percentage(unsigned long seed, void *buf,
+                                 unsigned int percentage,
+                                 unsigned int segment, unsigned int len,
+                                 char *pattern, unsigned int pbytes)
+{
+       unsigned int this_len;
+
+       if (percentage == 100) {
+               if (pbytes)
+                       fill_pattern(buf, len, pattern, pbytes);
+               else
+                       memset(buf, 0, len);
+               return;
+       }
+
+       if (segment > len)
+               segment = len;
+
+       while (len) {
+               /*
+                * Fill random chunk
+                */
+               this_len = (segment * (100 - percentage)) / 100;
+               if (this_len > len)
+                       this_len = len;
+
+               __fill_random_buf(buf, this_len, seed);
+
+               len -= this_len;
+               if (!len)
+                       break;
+               buf += this_len;
+
+               if (this_len > len)
+                       this_len = len;
+               else if (len - this_len <= sizeof(long))
+                       this_len = len;
+
+               if (pbytes)
+                       fill_pattern(buf, this_len, pattern, pbytes);
+               else
+                       memset(buf, 0, this_len);
+
+               len -= this_len;
+               buf += this_len;
+       }
+}
+
+unsigned long fill_random_buf_percentage(struct frand_state *fs, void *buf,
+                                        unsigned int percentage,
+                                        unsigned int segment, unsigned int len,
+                                        char *pattern, unsigned int pbytes)
+{
+       unsigned long r = __rand(fs);
+
+       if (sizeof(int) != sizeof(long *))
+               r *= (unsigned long) __rand(fs);
+
+       __fill_random_buf_percentage(r, buf, percentage, segment, len,
+                                       pattern, pbytes);
+       return r;
+}