/*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "random.h"
-#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/time.h>
#include "entropy.h"
+#include "hash.h"
+#include "ovs-thread.h"
+#include "timeval.h"
#include "util.h"
/* This is the 32-bit PRNG recommended in G. Marsaglia, "Xorshift RNGs",
* cryptographic-quality randomness. */
/* Current random state. */
-static uint32_t seed;
+DEFINE_STATIC_PER_THREAD_DATA(uint32_t, seed, 0);
static uint32_t random_next(void);
void
random_init(void)
{
- while (!seed) {
+ uint32_t *seedp = seed_get();
+ while (!*seedp) {
struct timeval tv;
uint32_t entropy;
+ pthread_t self;
- if (gettimeofday(&tv, NULL) < 0) {
- ovs_fatal(errno, "gettimeofday");
- }
+ xgettimeofday(&tv);
get_entropy_or_die(&entropy, 4);
+ self = pthread_self();
- seed = tv.tv_sec ^ tv.tv_usec ^ entropy;
+ *seedp = (tv.tv_sec ^ tv.tv_usec ^ entropy
+ ^ hash_bytes(&self, sizeof self, 0));
}
}
void
random_set_seed(uint32_t seed_)
{
- assert(seed_);
- seed = seed_;
+ ovs_assert(seed_);
+ *seed_get() = seed_;
}
void
return random_next();
}
+uint64_t
+random_uint64(void)
+{
+ uint64_t x;
+
+ random_init();
+
+ x = random_next();
+ x |= (uint64_t) random_next() << 32;
+ return x;
+}
+
int
random_range(int max)
{
static uint32_t
random_next(void)
{
- seed ^= seed << 13;
- seed ^= seed >> 17;
- seed ^= seed << 5;
+ uint32_t *seedp = seed_get_unsafe();
+
+ *seedp ^= *seedp << 13;
+ *seedp ^= *seedp >> 17;
+ *seedp ^= *seedp << 5;
- return seed;
+ return *seedp;
}