From 6dfd46b99af38cc1e5f702f53c59212129fe615e Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@suse.de>
Date: Wed, 7 Jun 2006 13:57:06 +0200
Subject: [PATCH] [PATCH] OS abstract out the random seed and value retrieval

This is pretty crappy on FreeBSD, the seed function doesn't seed the
state we want. But it works, so it'll have to suffice for now...
---
 fio.c        |  8 ++++----
 fio.h        |  8 ++++----
 init.c       |  8 ++++----
 os-freebsd.h | 21 +++++++++++++++++++++
 os-linux.h   | 22 ++++++++++++++++++++++
 5 files changed, 55 insertions(+), 12 deletions(-)

diff --git a/fio.c b/fio.c
index 1e94cc6f..09c960fd 100644
--- a/fio.c
+++ b/fio.c
@@ -160,7 +160,7 @@ static int get_next_offset(struct thread_data *td, unsigned long long *offset)
 		int loops = 50;
 
 		do {
-			lrand48_r(&td->random_state, &r);
+			r = os_random_long(&td->random_state);
 			b = ((max_blocks - 1) * r / (unsigned long long) (RAND_MAX+1.0));
 			rb = b + (td->file_offset / td->min_bs);
 			loops--;
@@ -188,7 +188,7 @@ static unsigned int get_next_buflen(struct thread_data *td)
 	if (td->min_bs == td->max_bs)
 		buflen = td->min_bs;
 	else {
-		lrand48_r(&td->bsrange_state, &r);
+		r = os_random_long(&td->bsrange_state);
 		buflen = (1 + (double) (td->max_bs - 1) * r / (RAND_MAX + 1.0));
 		buflen = (buflen + td->min_bs - 1) & ~(td->min_bs - 1);
 	}
@@ -250,7 +250,7 @@ static void fill_random_bytes(struct thread_data *td,
 	double r;
 
 	while (len) {
-		drand48_r(&td->verify_state, &r);
+		r = os_random_double(&td->verify_state);
 
 		/*
 		 * lrand48_r seems to be broken and only fill the bottom
@@ -363,7 +363,7 @@ static int get_rw_ddir(struct thread_data *td)
 			unsigned long v;
 			long r;
 
-			lrand48_r(&td->random_state, &r);
+			r = os_random_long(&td->random_state);
 			v = 100UL * r / (unsigned long) (RAND_MAX + 1.0);
 			if (v < td->rwmixread)
 				td->rwmix_ddir = DDIR_READ;
diff --git a/fio.h b/fio.h
index 89d7bf94..0b25bb8d 100644
--- a/fio.h
+++ b/fio.h
@@ -169,8 +169,8 @@ struct thread_data {
 
 	char *ioscheduler;
 
-	struct drand48_data bsrange_state;
-	struct drand48_data verify_state;
+	os_random_state_t bsrange_state;
+	os_random_state_t verify_state;
 
 	int shm_id;
 
@@ -207,7 +207,7 @@ struct thread_data {
 	unsigned long long last_pos;
 	sem_t mutex;
 
-	struct drand48_data random_state;
+	os_random_state_t random_state;
 	unsigned long *file_map;
 	unsigned int num_maps;
 
@@ -237,7 +237,7 @@ struct thread_data {
 	unsigned int do_disk_util;
 	unsigned int override_sync;
 
-	struct drand48_data rwmix_state;
+	os_random_state_t rwmix_state;
 	struct timeval rwmix_switch;
 	int rwmix_ddir;
 
diff --git a/init.c b/init.c
index d02056cc..1bd79e27 100644
--- a/init.c
+++ b/init.c
@@ -256,9 +256,9 @@ int init_random_state(struct thread_data *td)
 
 	close(fd);
 
-	srand48_r(seeds[0], &td->bsrange_state);
-	srand48_r(seeds[1], &td->verify_state);
-	srand48_r(seeds[2], &td->rwmix_state);
+	os_random_seed(seeds[0], &td->bsrange_state);
+	os_random_seed(seeds[1], &td->verify_state);
+	os_random_seed(seeds[2], &td->rwmix_state);
 
 	if (td->sequential)
 		return 0;
@@ -272,7 +272,7 @@ int init_random_state(struct thread_data *td)
 	td->num_maps = num_maps;
 	memset(td->file_map, 0, num_maps * sizeof(long));
 
-	srand48_r(seeds[3], &td->random_state);
+	os_random_seed(seeds[3], &td->random_state);
 	return 0;
 }
 
diff --git a/os-freebsd.h b/os-freebsd.h
index 31fa0107..b56ba802 100644
--- a/os-freebsd.h
+++ b/os-freebsd.h
@@ -11,6 +11,7 @@
 #define OS_MAP_ANON		(MAP_ANON)
 
 typedef unsigned long os_cpu_mask_t;
+typedef unsigned int os_random_state_t;
 
 /*
  * FIXME
@@ -30,4 +31,24 @@ static inline unsigned long long os_phys_mem(void)
 	return mem;
 }
 
+static inline void os_random_seed(unsigned long seed, os_random_state_t *rs)
+{
+	srand(seed);
+}
+
+static inline long os_random_long(os_random_state_t *rs)
+{
+	long val;
+
+	val = rand_r(rs);
+	return val;
+}
+
+static inline double os_random_double(os_random_state_t *rs)
+{
+	double val;
+
+	val = (double) rand_r(rs);
+	return val;
+}
 #endif
diff --git a/os-linux.h b/os-linux.h
index f2df97d3..f9094cb4 100644
--- a/os-linux.h
+++ b/os-linux.h
@@ -20,6 +20,7 @@
 #define OS_MAP_ANON		(MAP_ANONYMOUS)
 
 typedef cpu_set_t os_cpu_mask_t;
+typedef struct drand48_data os_random_state_t;
 
 /*
  * we want fadvise64 really, but it's so tangled... later
@@ -99,4 +100,25 @@ static inline unsigned long long os_phys_mem(void)
 	return (unsigned long long) pages * (unsigned long long) pagesize;
 }
 
+static inline void os_random_seed(unsigned long seed, os_random_state_t *rs)
+{
+	srand48_r(seed, rs);
+}
+
+static inline long os_random_long(os_random_state_t *rs)
+{
+	long val;
+
+	lrand48_r(rs, &val);
+	return val;
+}
+
+static inline double os_random_double(os_random_state_t *rs)
+{
+	double val;
+
+	drand48_r(rs, &val);
+	return val;
+}
+
 #endif
-- 
2.25.1