source: doc/theses/colby_parsons_MMAth/benchmarks/mutex_stmt/bench.h

#pragma once

#if defined(__cforall)
extern "C" {
#endif
        #include <stdlib.h>
        #include <stdint.h>                             // uint64_t
        #include <unistd.h>                             // sysconf
#if ! defined(__cforall)
        #include <time.h>
        #include <sys/time.h>
#else
}
#include <time.hfa>
#endif

#define L1 l1
#define L2 L1, l2
#define L3 L2, l3
#define L4 L3, l4
#define L5 L4, l5
#define L6 L5, l6
#define L7 L6, l7
#define L8 L7, l8

static inline uint64_t bench_time() {
        struct timespec ts;
        clock_gettime( CLOCK_THREAD_CPUTIME_ID, &ts );
        return 1000000000LL * ts.tv_sec + ts.tv_nsec;
} // bench_time


#if defined(__cforall)
struct test_spinlock {
        volatile bool lock;
};

static inline void lock( test_spinlock & this ) {
        for ( ;; ) {
                if ( (this.lock == 0) && (__atomic_test_and_set( &this.lock, __ATOMIC_ACQUIRE ) == 0) ) break;
        }
}

static inline void unlock( test_spinlock & this ) {
        __atomic_clear( &this.lock, __ATOMIC_RELEASE );
}
#endif

size_t threads = 1, num_locks = -1;

#define BENCH_START()                           \
        if ( argc > 3 ) exit( EXIT_FAILURE );   \
        if ( argc == 2 ) {                      \
                threads = atoi( argv[1] );      \
        } else if ( argc == 3 ) {                       \
                threads = atoi( argv[1] );      \
        num_locks = atoi( argv[2] );    \
        }

#define BENCH(statement, output, done_flag)             \
        uint64_t count = 0;             \
    while (true) {          \
        statement;                              \
    count++;                \
    if (done_flag) break; \
    }                       \
    __atomic_add_fetch(&output, count, __ATOMIC_SEQ_CST);
        // EndTime = bench_time();                      \
        // double output = (double)( EndTime - StartTime ) / times;


#if defined(__cforall)
Duration default_preemption() {
        return 0;
}
#endif
#if defined(__U_CPLUSPLUS__)
unsigned int uDefaultPreemption() {
        return 0;
}
#endif

// splitmix64 rand num generator
// https://rosettacode.org/wiki/Pseudo-random_numbers/Splitmix64
uint64_t state;                                  /* The state can be seeded with any (upto) 64 bit integer value. */

uint64_t next_int() {
    state += 0x9e3779b97f4a7c15;               /* increment the state variable */
    uint64_t z = state;                          /* copy the state to a working variable */
    z = (z ^ (z >> 30)) * 0xbf58476d1ce4e5b9;  /* xor the variable with the variable right bit shifted 30 then multiply by a constant */
    z = (z ^ (z >> 27)) * 0x94d049bb133111eb;  /* xor the variable with the variable right bit shifted 27 then multiply by a constant */
    return z ^ (z >> 31);                      /* return the variable xored with itself right bit shifted 31 */
}