1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16/**
17 ************************************************************************
18 * @file        M4PSW_Trace.c
19 * @brief        Trace function for trace macros
20 * @note        This file gives the implementation of the trace function used
21 *                in the trace instrumentation macros
22 ************************************************************************
23*/
24
25#include <stdio.h>  /*for printf */
26#include <stdarg.h> /* ANSI C macros and defs for variable args */
27#include <stdlib.h>
28#include <string.h>
29#include <time.h>
30
31#include "M4OSA_Types.h"
32#include "M4OSA_Error.h"
33#include "M4OSA_Memory.h"
34#include "M4OSA_Mutex.h"
35/**
36 ************************************************************************
37 * @fn         M4OSA_ERR M4OSA_randInit()
38 * @brief      this function initialize the number generator
39 *               this function must be called once before any call to M4OSA_rand()
40 *               need the stdlib and time libraries
41 * @note
42 * @param
43 * @return     M4NO_ERROR
44 ************************************************************************
45*/
46
47M4OSA_ERR M4OSA_randInit()
48{
49    int i;
50
51    srand(time(NULL));
52
53    /* Windows' rand is rotten, the first generated value after the init
54    above is not random enough, so let's shake things a little... */
55
56    for (i=0; i<100; i++) rand();
57
58    return M4NO_ERROR;
59}
60/**
61 ************************************************************************
62 * @fn           M4OSA_ERR M4OSA_rand(M4OSA_Int32* out_value, M4OSA_UInt32 max_value)
63 * @brief       This function gives a random number between 1 and max_value
64 *               (inclusive) with approximately equal probability, and
65 *               returns this number in out_value. For instance, a max_value
66 *             of 6 will simulate a fair 6-sided dice roll.
67 * @note
68 * @param      out_value (OUT): on return, points to random result
69 * @param       max_value (IN): max expected value
70 * @return     M4NO_ERROR
71 ************************************************************************
72*/
73
74M4OSA_ERR M4OSA_rand(M4OSA_Int32* out_value, M4OSA_UInt32 max_value)
75{
76    if( (out_value == M4OSA_NULL) || (max_value < 1) )
77    {
78        return M4ERR_PARAMETER;
79    }
80
81    (*out_value) = rand();
82    /* notice this algorithm will only work for max_values such that the multiplication
83    won't overflow, which means that max_value typically shouldn't go over the range of
84    an Int16. */
85    (*out_value) = (((*out_value) * max_value) / ((M4OSA_UInt32)RAND_MAX + 1)) + 1;
86
87    return M4NO_ERROR;
88}
89
90
91