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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
************************************************************************
* @file M4PSW_Trace.c
* @brief Trace function for trace macros
* @note This file gives the implementation of the trace function used
* in the trace instrumentation macros
************************************************************************
*/
#include <stdio.h> /*for printf */
#include <stdarg.h> /* ANSI C macros and defs for variable args */
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "M4OSA_Types.h"
#include "M4OSA_Error.h"
#include "M4OSA_Memory.h"
#include "M4OSA_Mutex.h"
/**
************************************************************************
* @fn M4OSA_ERR M4OSA_randInit()
* @brief this function initialize the number generator
* this function must be called once before any call to M4OSA_rand()
* need the stdlib and time libraries
* @note
* @param
* @return M4NO_ERROR
************************************************************************
*/
M4OSA_ERR M4OSA_randInit()
{
int i;
srand(time(NULL));
/* Windows' rand is rotten, the first generated value after the init
above is not random enough, so let's shake things a little... */
for (i=0; i<100; i++) rand();
return M4NO_ERROR;
}
/**
************************************************************************
* @fn M4OSA_ERR M4OSA_rand(M4OSA_Int32* out_value, M4OSA_UInt32 max_value)
* @brief This function gives a random number between 1 and max_value
* (inclusive) with approximately equal probability, and
* returns this number in out_value. For instance, a max_value
* of 6 will simulate a fair 6-sided dice roll.
* @note
* @param out_value (OUT): on return, points to random result
* @param max_value (IN): max expected value
* @return M4NO_ERROR
************************************************************************
*/
M4OSA_ERR M4OSA_rand(M4OSA_Int32* out_value, M4OSA_UInt32 max_value)
{
if( (out_value == M4OSA_NULL) || (max_value < 1) )
{
return M4ERR_PARAMETER;
}
(*out_value) = rand();
/* notice this algorithm will only work for max_values such that the multiplication
won't overflow, which means that max_value typically shouldn't go over the range of
an Int16. */
(*out_value) = (((*out_value) * max_value) / ((M4OSA_UInt32)RAND_MAX + 1)) + 1;
return M4NO_ERROR;
}
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