/* Make sure timers don't return early
 *              by: john stultz (johnstul@us.ibm.com)
 *                  John Stultz (john.stultz@linaro.org)
 *              (C) Copyright IBM 2012
 *              (C) Copyright Linaro 2013 2015
 *              Licensed under the GPLv2
 *
 *  To build:
 *      $ gcc nanosleep.c -o nanosleep -lrt
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include <sys/timex.h>
#include <string.h>
#include <signal.h>
#include <include/vdso/time64.h>
#include "kselftest.h"

/* CLOCK_HWSPECIFIC == CLOCK_SGI_CYCLE (Deprecated) */
#define CLOCK_HWSPECIFIC                10

#define UNSUPPORTED 0xf00f

char *clockstring(int clockid)
{
        switch (clockid) {
        case CLOCK_REALTIME:
                return "CLOCK_REALTIME";
        case CLOCK_MONOTONIC:
                return "CLOCK_MONOTONIC";
        case CLOCK_PROCESS_CPUTIME_ID:
                return "CLOCK_PROCESS_CPUTIME_ID";
        case CLOCK_THREAD_CPUTIME_ID:
                return "CLOCK_THREAD_CPUTIME_ID";
        case CLOCK_MONOTONIC_RAW:
                return "CLOCK_MONOTONIC_RAW";
        case CLOCK_REALTIME_COARSE:
                return "CLOCK_REALTIME_COARSE";
        case CLOCK_MONOTONIC_COARSE:
                return "CLOCK_MONOTONIC_COARSE";
        case CLOCK_BOOTTIME:
                return "CLOCK_BOOTTIME";
        case CLOCK_REALTIME_ALARM:
                return "CLOCK_REALTIME_ALARM";
        case CLOCK_BOOTTIME_ALARM:
                return "CLOCK_BOOTTIME_ALARM";
        case CLOCK_TAI:
                return "CLOCK_TAI";
        };
        return "UNKNOWN_CLOCKID";
}

/* returns 1 if a <= b, 0 otherwise */
static inline int in_order(struct timespec a, struct timespec b)
{
        if (a.tv_sec < b.tv_sec)
                return 1;
        if (a.tv_sec > b.tv_sec)
                return 0;
        if (a.tv_nsec > b.tv_nsec)
                return 0;
        return 1;
}

struct timespec timespec_add(struct timespec ts, unsigned long long ns)
{
        ts.tv_nsec += ns;
        while (ts.tv_nsec >= NSEC_PER_SEC) {
                ts.tv_nsec -= NSEC_PER_SEC;
                ts.tv_sec++;
        }
        return ts;
}

int nanosleep_test(int clockid, long long ns)
{
        struct timespec now, target, rel;

        /* First check abs time */
        if (clock_gettime(clockid, &now))
                return UNSUPPORTED;
        target = timespec_add(now, ns);

        if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL))
                return UNSUPPORTED;
        clock_gettime(clockid, &now);

        if (!in_order(target, now))
                return -1;

        /* Second check reltime */
        clock_gettime(clockid, &now);
        rel.tv_sec = 0;
        rel.tv_nsec = 0;
        rel = timespec_add(rel, ns);
        target = timespec_add(now, ns);
        clock_nanosleep(clockid, 0, &rel, NULL);
        clock_gettime(clockid, &now);

        if (!in_order(target, now))
                return -1;
        return 0;
}

static void dummy_event_handler(int val)
{
        /* No action needed */
}

static int nanosleep_test_remaining(int clockid)
{
        struct timespec rqtp = {}, rmtp = {};
        struct itimerspec itimer = {};
        struct sigaction sa = {};
        timer_t timer;
        int ret;

        sa.sa_handler = dummy_event_handler;
        ret = sigaction(SIGALRM, &sa, NULL);
        if (ret)
                return -1;

        ret = timer_create(clockid, NULL, &timer);
        if (ret)
                return -1;

        itimer.it_value.tv_nsec = NSEC_PER_SEC / 4;
        ret = timer_settime(timer, 0, &itimer, NULL);
        if (ret)
                return -1;

        rqtp.tv_nsec = NSEC_PER_SEC / 2;
        ret = clock_nanosleep(clockid, 0, &rqtp, &rmtp);
        if (ret != EINTR)
                return -1;

        ret = timer_delete(timer);
        if (ret)
                return -1;

        sa.sa_handler = SIG_DFL;
        ret = sigaction(SIGALRM, &sa, NULL);
        if (ret)
                return -1;

        if (!in_order((struct timespec) {}, rmtp))
                return -1;

        if (!in_order(rmtp, rqtp))
                return -1;

        return 0;
}

int main(int argc, char **argv)
{
        long long length;
        int clockid, ret;
        int max_clocks = CLOCK_TAI + 1;

        ksft_print_header();
        ksft_set_plan(max_clocks);

        for (clockid = CLOCK_REALTIME; clockid < max_clocks; clockid++) {

                /* Skip cputime clockids since nanosleep won't increment cputime */
                if (clockid == CLOCK_PROCESS_CPUTIME_ID ||
                                clockid == CLOCK_THREAD_CPUTIME_ID ||
                                clockid == CLOCK_HWSPECIFIC) {
                        ksft_test_result_skip("%-31s\n", clockstring(clockid));
                        continue;
                }

                fflush(stdout);

                length = 10;
                while (length <= (NSEC_PER_SEC * 10)) {
                        ret = nanosleep_test(clockid, length);
                        if (ret == UNSUPPORTED) {
                                ksft_test_result_skip("%-31s\n", clockstring(clockid));
                                goto next;
                        }
                        if (ret < 0) {
                                ksft_test_result_fail("%-31s\n", clockstring(clockid));
                                ksft_exit_fail();
                        }
                        length *= 100;
                }
                ret = nanosleep_test_remaining(clockid);
                if (ret < 0) {
                        ksft_test_result_fail("%-31s\n", clockstring(clockid));
                        ksft_exit_fail();
                }
                ksft_test_result_pass("%-31s\n", clockstring(clockid));
next:
                ret = 0;
        }
        ksft_exit_pass();
}