projects / ceph.git / blame
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|---|---|---|
| 7c673cae FG |
1 | /*- |
| 2 | * BSD LICENSE | |
| 3 | * | |
| 4 | * Copyright(c) 2010-2014 Intel Corporation. All rights reserved. | |
| 5 | * All rights reserved. | |
| 6 | * | |
| 7 | * Redistribution and use in source and binary forms, with or without | |
| 8 | * modification, are permitted provided that the following conditions | |
| 9 | * are met: | |
| 10 | * | |
| 11 | * * Redistributions of source code must retain the above copyright | |
| 12 | * notice, this list of conditions and the following disclaimer. | |
| 13 | * * Redistributions in binary form must reproduce the above copyright | |
| 14 | * notice, this list of conditions and the following disclaimer in | |
| 15 | * the documentation and/or other materials provided with the | |
| 16 | * distribution. | |
| 17 | * * Neither the name of Intel Corporation nor the names of its | |
| 18 | * contributors may be used to endorse or promote products derived | |
| 19 | * from this software without specific prior written permission. | |
| 20 | * | |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| 22 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| 23 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
| 24 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
| 25 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 26 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
| 27 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 28 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 29 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 30 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 31 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 32 | */ | |
| 33 | ||
| 34 | #ifndef _RTE_RANDOM_H_ | |
| 35 | #define _RTE_RANDOM_H_ | |
| 36 | ||
| 37 | /** | |
| 38 | * @file | |
| 39 | * | |
| 40 | * Pseudo-random Generators in RTE | |
| 41 | */ | |
| 42 | ||
| 43 | #ifdef __cplusplus | |
| 44 | extern "C" { | |
| 45 | #endif | |
| 46 | ||
| 47 | #include <stdint.h> | |
| 48 | #include <stdlib.h> | |
| 49 | ||
| 50 | /** | |
| 51 | * Seed the pseudo-random generator. | |
| 52 | * | |
| 53 | * The generator is automatically seeded by the EAL init with a timer | |
| 54 | * value. It may need to be re-seeded by the user with a real random | |
| 55 | * value. | |
| 56 | * | |
| 57 | * @param seedval | |
| 58 | * The value of the seed. | |
| 59 | */ | |
| 60 | static inline void | |
| 61 | rte_srand(uint64_t seedval) | |
| 62 | { | |
| 63 | srand48((long unsigned int)seedval); | |
| 64 | } | |
| 65 | ||
| 66 | /** | |
| 67 | * Get a pseudo-random value. | |
| 68 | * | |
| 69 | * This function generates pseudo-random numbers using the linear | |
| 70 | * congruential algorithm and 48-bit integer arithmetic, called twice | |
| 71 | * to generate a 64-bit value. | |
| 72 | * | |
| 73 | * @return | |
| 74 | * A pseudo-random value between 0 and (1<<64)-1. | |
| 75 | */ | |
| 76 | static inline uint64_t | |
| 77 | rte_rand(void) | |
| 78 | { | |
| 79 | uint64_t val; | |
| 80 | val = lrand48(); | |
| 81 | val <<= 32; | |
| 82 | val += lrand48(); | |
| 83 | return val; | |
| 84 | } | |
| 85 | ||
| 86 | #ifdef __cplusplus | |
| 87 | } | |
| 88 | #endif | |
| 89 | ||
| 90 | ||
| 91 | #endif /* _RTE_PER_LCORE_H_ */ |