snp-lab-code/P10_Sync/Sync/banking/a2/mrandom.h

75 lines
2.3 KiB
C
Raw Permalink Normal View History

2020-05-10 02:07:29 +02:00
#ifndef MY_RANDOMGENERATOR_DEFINITIONS
#define MY_RANDOMGENERATOR_DEFINITIONS
#include <sys/time.h>
#include <assert.h>
//******************************************************************************
// Course: BSy
// File: mrandom.h
// Author: M. Thaler, ZHAW
// Purpose: thread safe random functions (reentrant)
// Version: v.fs20
//******************************************************************************
// date type: mrand_t
//
// functions:
// - void mrandInit(mrand_t *mrt) -> initialize with fixed seed
// - unsigned int mrandUInt(mrand_t *mrt) -> unsigned random number
// - unsigned int mrandRange(int low, int high, mrand_t *mrt)
// -> random number within range
//
/******************************************************************************/
// constanst for ecuyer generator: length approx 8 x 10^12
#define M1 2147483563
#define M2 2147483399
#define A1 40014
#define A2 40692
#define Q1 53668
#define Q2 52774
#define R1 12211
#define R2 3791
#define MRAND_MAX M1-1
/******************************************************************************/
typedef struct mrand_t { unsigned int s1; \
unsigned int s2; } mrand_t;
void mrandInit(unsigned int seed, mrand_t *mrt) {
mrt->s1 = 33777 + seed * 777;
mrt->s2 = 9777572 + seed * 33775;
}
unsigned int mrandUInt(mrand_t *mrt) {
unsigned int rv;
mrt->s1 = A1 * (mrt->s1 % Q1) - mrt->s1 * (mrt->s1/Q1);
if (mrt->s1 <= 0) mrt->s1 += M1;
mrt->s2 = A2 * (mrt->s2 % Q2) - mrt->s2 * (mrt->s2/Q2);
if (mrt->s2 <= 0) mrt->s2 += M2;
rv = (mrt->s1 + mrt->s2) % M1;
return rv;
}
double mrandDouble(mrand_t *mrt) {
unsigned int rv;
double dv;
mrt->s1 = A1 * (mrt->s1 % Q1) - mrt->s1 * (mrt->s1/Q1);
if (mrt->s1 <= 0) mrt->s1 += M1;
mrt->s2 = A2 * (mrt->s2 % Q2) - mrt->s2 * (mrt->s2/Q2);
if (mrt->s2 <= 0) mrt->s2 += M2;
rv = (mrt->s1 + mrt->s2) % M1;
dv = (double)rv / ((double)(M1-1));
return dv;
}
unsigned int mrandRange(unsigned int low, unsigned int high, mrand_t *mrt) {
assert(low <= high);
double drv = mrandDouble(mrt);
unsigned int av = (unsigned int)(drv * (double)(high-low) + 0.5);
return low + av;
}
/******************************************************************************/
#endif