eal: simplify meson build of common directory

[dpdk.git] / lib / librte_eal / common / include / rte_random.h

diff --git a/lib/librte_eal/common/include/rte_random.h b/lib/librte_eal/common/include/rte_random.h
index 72ccebd..2b30ec8 100644 (file)
--- a/lib/librte_eal/common/include/rte_random.h
+++ b/lib/librte_eal/common/include/rte_random.h
@@ -1,35 +1,5 @@
-/*-
- *   BSD LICENSE
- * 
- *   Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
- *   All rights reserved.
- * 
- *   Redistribution and use in source and binary forms, with or without 
- *   modification, are permitted provided that the following conditions 
- *   are met:
- * 
- *     * Redistributions of source code must retain the above copyright 
- *       notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above copyright 
- *       notice, this list of conditions and the following disclaimer in 
- *       the documentation and/or other materials provided with the 
- *       distribution.
- *     * Neither the name of Intel Corporation nor the names of its 
- *       contributors may be used to endorse or promote products derived 
- *       from this software without specific prior written permission.
- * 
- *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
- *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
- *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 
- *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
- *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
- *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
- *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
- *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
- *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
- *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
- *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- * 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2014 Intel Corporation
  */
 
 #ifndef _RTE_RANDOM_H_
@@ -46,7 +16,8 @@ extern "C" {
 #endif
 
 #include <stdint.h>
-#include <stdlib.h>
+
+#include <rte_compat.h>
 
 /**
  * Seed the pseudo-random generator.
@@ -55,38 +26,49 @@ extern "C" {
  * value. It may need to be re-seeded by the user with a real random
  * value.
  *
+ * This function is not multi-thread safe in regards to other
+ * rte_srand() calls, nor is it in relation to concurrent rte_rand()
+ * calls.
+ *
  * @param seedval
  *   The value of the seed.
  */
-static inline void
-rte_srand(uint64_t seedval)
-{
-       srand48((long unsigned int)seedval);
-}
+void
+rte_srand(uint64_t seedval);
 
 /**
  * Get a pseudo-random value.
  *
- * This function generates pseudo-random numbers using the linear
- * congruential algorithm and 48-bit integer arithmetic, called twice
- * to generate a 64-bit value.
+ * The generator is not cryptographically secure.
+ *
+ * If called from lcore threads, this function is thread-safe.
  *
  * @return
  *   A pseudo-random value between 0 and (1<<64)-1.
  */
-static inline uint64_t
-rte_rand(void)
-{
-       uint64_t val;
-       val = lrand48();
-       val <<= 32;
-       val += lrand48();
-       return val;
-}
+uint64_t
+rte_rand(void);
+
+/**
+ * Generates a pseudo-random number with an upper bound.
+ *
+ * This function returns an uniformly distributed (unbiased) random
+ * number less than a user-specified maximum value.
+ *
+ * If called from lcore threads, this function is thread-safe.
+ *
+ * @param upper_bound
+ *   The upper bound of the generated number.
+ * @return
+ *   A pseudo-random value between 0 and (upper_bound-1).
+ */
+__rte_experimental
+uint64_t
+rte_rand_max(uint64_t upper_bound);
 
 #ifdef __cplusplus
 }
 #endif
 
 
-#endif /* _RTE_PER_LCORE_H_ */
+#endif /* _RTE_RANDOM_H_ */