libtopo/test/test.c

#include <stdint.h>
#include <unistd.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>

#include "topo.h"

#define S2NS (1000000000UL)

static inline uint64_t
get_uptime()
{
	struct timespec tp;
	clock_gettime(CLOCK_MONOTONIC, &tp);
    return ((uint64_t)tp.tv_sec * S2NS + (uint64_t)tp.tv_nsec);
}

void test(const char * case_name, struct timespec * ts)
{
    uint64_t slow;
    uint64_t fast;

    slow = get_uptime();
    if (nanosleep(ts, NULL) != 0) {
        perror("nanosleep() interrupted!");
        exit(-1);
    }
    slow = get_uptime() - slow;

    fast = topo_uptime_ns();
    if (nanosleep(ts, NULL) != 0) {
        perror("nanosleep() interrupted!");
        exit(-1);
    }
    fast = topo_uptime_ns() - fast;

    printf("%s: clock_gettime(): %lu, topo_uptime_ns(): %lu, %% diff: %.2f%%\n", case_name, slow, fast, ((float)fast - (float)slow) / (float)slow * 100);
}

int ts_test()
{
    struct timespec ts;
    // 1s
    ts.tv_nsec = 0;
    ts.tv_sec = 1;
    test("1s", &ts);

    // 100ms
    ts.tv_nsec = 100000000;
    ts.tv_sec = 0;
    test("100ms", &ts);

    // 10ms
    ts.tv_nsec = 10000000;
    ts.tv_sec = 0;
    test("10ms", &ts);

    // 1ms
    ts.tv_nsec = 1000000;
    ts.tv_sec = 0;
    test("1ms", &ts);

    // 100us
    ts.tv_nsec = 100000;
    ts.tv_sec = 0;
    test("100us", &ts);

    // 10us
    ts.tv_nsec = 10000;
    ts.tv_sec = 0;
    test("10us", &ts);

    // 1us
    ts.tv_nsec = 1000;
    ts.tv_sec = 0;
    test("1us", &ts);

    // 100ns
    ts.tv_nsec = 100;
    ts.tv_sec = 0;
    test("100ns", &ts);

    // 10ns
    ts.tv_nsec = 10;
    ts.tv_sec = 0;
    test("10ns", &ts);

    // 1ns
    ts.tv_nsec = 1;
    ts.tv_sec = 0;
    test("1ns", &ts);

    return 0;
}

int main()
{
    topo_init(1);
    topo_init(1);
    ts_test();
    return 0;
}