1/* Make sure timers don't return early
  2 *              by: john stultz (johnstul@us.ibm.com)
  3 *		    John Stultz (john.stultz@linaro.org)
  4 *              (C) Copyright IBM 2012
  5 *              (C) Copyright Linaro 2013 2015
  6 *              Licensed under the GPLv2
  7 *
  8 *  To build:
  9 *	$ gcc nanosleep.c -o nanosleep -lrt
 10 *
 11 *   This program is free software: you can redistribute it and/or modify
 12 *   it under the terms of the GNU General Public License as published by
 13 *   the Free Software Foundation, either version 2 of the License, or
 14 *   (at your option) any later version.
 15 *
 16 *   This program is distributed in the hope that it will be useful,
 17 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 18 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 19 *   GNU General Public License for more details.
 20 */
 21
 22#include <errno.h>
 23#include <stdio.h>
 24#include <stdlib.h>
 25#include <time.h>
 26#include <sys/time.h>
 27#include <sys/timex.h>
 28#include <string.h>
 29#include <signal.h>
 30#ifdef KTEST
 31#include "../kselftest.h"
 32#else
 33static inline int ksft_exit_pass(void)
 34{
 35	exit(0);
 36}
 37static inline int ksft_exit_fail(void)
 38{
 39	exit(1);
 40}
 41#endif
 42
 43#define NSEC_PER_SEC 1000000000ULL
 44
 45#define CLOCK_REALTIME			0
 46#define CLOCK_MONOTONIC			1
 47#define CLOCK_PROCESS_CPUTIME_ID	2
 48#define CLOCK_THREAD_CPUTIME_ID		3
 49#define CLOCK_MONOTONIC_RAW		4
 50#define CLOCK_REALTIME_COARSE		5
 51#define CLOCK_MONOTONIC_COARSE		6
 52#define CLOCK_BOOTTIME			7
 53#define CLOCK_REALTIME_ALARM		8
 54#define CLOCK_BOOTTIME_ALARM		9
 55#define CLOCK_HWSPECIFIC		10
 56#define CLOCK_TAI			11
 57#define NR_CLOCKIDS			12
 58
 59#define UNSUPPORTED 0xf00f
 60
 61char *clockstring(int clockid)
 62{
 63	switch (clockid) {
 64	case CLOCK_REALTIME:
 65		return "CLOCK_REALTIME";
 66	case CLOCK_MONOTONIC:
 67		return "CLOCK_MONOTONIC";
 68	case CLOCK_PROCESS_CPUTIME_ID:
 69		return "CLOCK_PROCESS_CPUTIME_ID";
 70	case CLOCK_THREAD_CPUTIME_ID:
 71		return "CLOCK_THREAD_CPUTIME_ID";
 72	case CLOCK_MONOTONIC_RAW:
 73		return "CLOCK_MONOTONIC_RAW";
 74	case CLOCK_REALTIME_COARSE:
 75		return "CLOCK_REALTIME_COARSE";
 76	case CLOCK_MONOTONIC_COARSE:
 77		return "CLOCK_MONOTONIC_COARSE";
 78	case CLOCK_BOOTTIME:
 79		return "CLOCK_BOOTTIME";
 80	case CLOCK_REALTIME_ALARM:
 81		return "CLOCK_REALTIME_ALARM";
 82	case CLOCK_BOOTTIME_ALARM:
 83		return "CLOCK_BOOTTIME_ALARM";
 84	case CLOCK_TAI:
 85		return "CLOCK_TAI";
 86	};
 87	return "UNKNOWN_CLOCKID";
 88}
 89
 90/* returns 1 if a <= b, 0 otherwise */
 91static inline int in_order(struct timespec a, struct timespec b)
 92{
 93	if (a.tv_sec < b.tv_sec)
 94		return 1;
 95	if (a.tv_sec > b.tv_sec)
 96		return 0;
 97	if (a.tv_nsec > b.tv_nsec)
 98		return 0;
 99	return 1;
100}
101
102struct timespec timespec_add(struct timespec ts, unsigned long long ns)
103{
104	ts.tv_nsec += ns;
105	while (ts.tv_nsec >= NSEC_PER_SEC) {
106		ts.tv_nsec -= NSEC_PER_SEC;
107		ts.tv_sec++;
108	}
109	return ts;
110}
111
112int nanosleep_test(int clockid, long long ns)
113{
114	struct timespec now, target, rel;
115
116	/* First check abs time */
117	if (clock_gettime(clockid, &now))
118		return UNSUPPORTED;
119	target = timespec_add(now, ns);
120
121	if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL))
122		return UNSUPPORTED;
123	clock_gettime(clockid, &now);
124
125	if (!in_order(target, now))
126		return -1;
127
128	/* Second check reltime */
129	clock_gettime(clockid, &now);
130	rel.tv_sec = 0;
131	rel.tv_nsec = 0;
132	rel = timespec_add(rel, ns);
133	target = timespec_add(now, ns);
134	clock_nanosleep(clockid, 0, &rel, NULL);
135	clock_gettime(clockid, &now);
136
137	if (!in_order(target, now))
138		return -1;
139	return 0;
140}
141
142int main(int argc, char **argv)
143{
144	long long length;
145	int clockid, ret;
146
147	for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) {
148
149		/* Skip cputime clockids since nanosleep won't increment cputime */
150		if (clockid == CLOCK_PROCESS_CPUTIME_ID ||
151				clockid == CLOCK_THREAD_CPUTIME_ID ||
152				clockid == CLOCK_HWSPECIFIC)
153			continue;
154
155		printf("Nanosleep %-31s ", clockstring(clockid));
156
157		length = 10;
158		while (length <= (NSEC_PER_SEC * 10)) {
159			ret = nanosleep_test(clockid, length);
160			if (ret == UNSUPPORTED) {
161				printf("[UNSUPPORTED]\n");
162				goto next;
163			}
164			if (ret < 0) {
165				printf("[FAILED]\n");
166				return ksft_exit_fail();
167			}
168			length *= 100;
169		}
170		printf("[OK]\n");
171next:
172		ret = 0;
173	}
174	return ksft_exit_pass();
175}