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#include "../kselftest.h"
31
32#define NSEC_PER_SEC 1000000000ULL
33
34#define CLOCK_REALTIME			0
35#define CLOCK_MONOTONIC			1
36#define CLOCK_PROCESS_CPUTIME_ID	2
37#define CLOCK_THREAD_CPUTIME_ID		3
38#define CLOCK_MONOTONIC_RAW		4
39#define CLOCK_REALTIME_COARSE		5
40#define CLOCK_MONOTONIC_COARSE		6
41#define CLOCK_BOOTTIME			7
42#define CLOCK_REALTIME_ALARM		8
43#define CLOCK_BOOTTIME_ALARM		9
44#define CLOCK_HWSPECIFIC		10
45#define CLOCK_TAI			11
46#define NR_CLOCKIDS			12
47
48#define UNSUPPORTED 0xf00f
49
50char *clockstring(int clockid)
51{
52	switch (clockid) {
53	case CLOCK_REALTIME:
54		return "CLOCK_REALTIME";
55	case CLOCK_MONOTONIC:
56		return "CLOCK_MONOTONIC";
57	case CLOCK_PROCESS_CPUTIME_ID:
58		return "CLOCK_PROCESS_CPUTIME_ID";
59	case CLOCK_THREAD_CPUTIME_ID:
60		return "CLOCK_THREAD_CPUTIME_ID";
61	case CLOCK_MONOTONIC_RAW:
62		return "CLOCK_MONOTONIC_RAW";
63	case CLOCK_REALTIME_COARSE:
64		return "CLOCK_REALTIME_COARSE";
65	case CLOCK_MONOTONIC_COARSE:
66		return "CLOCK_MONOTONIC_COARSE";
67	case CLOCK_BOOTTIME:
68		return "CLOCK_BOOTTIME";
69	case CLOCK_REALTIME_ALARM:
70		return "CLOCK_REALTIME_ALARM";
71	case CLOCK_BOOTTIME_ALARM:
72		return "CLOCK_BOOTTIME_ALARM";
73	case CLOCK_TAI:
74		return "CLOCK_TAI";
75	};
76	return "UNKNOWN_CLOCKID";
77}
78
79/* returns 1 if a <= b, 0 otherwise */
80static inline int in_order(struct timespec a, struct timespec b)
81{
82	if (a.tv_sec < b.tv_sec)
83		return 1;
84	if (a.tv_sec > b.tv_sec)
85		return 0;
86	if (a.tv_nsec > b.tv_nsec)
87		return 0;
88	return 1;
89}
90
91struct timespec timespec_add(struct timespec ts, unsigned long long ns)
92{
93	ts.tv_nsec += ns;
94	while (ts.tv_nsec >= NSEC_PER_SEC) {
95		ts.tv_nsec -= NSEC_PER_SEC;
96		ts.tv_sec++;
97	}
98	return ts;
99}
100
101int nanosleep_test(int clockid, long long ns)
102{
103	struct timespec now, target, rel;
104
105	/* First check abs time */
106	if (clock_gettime(clockid, &now))
107		return UNSUPPORTED;
108	target = timespec_add(now, ns);
109
110	if (clock_nanosleep(clockid, TIMER_ABSTIME, &target, NULL))
111		return UNSUPPORTED;
112	clock_gettime(clockid, &now);
113
114	if (!in_order(target, now))
115		return -1;
116
117	/* Second check reltime */
118	clock_gettime(clockid, &now);
119	rel.tv_sec = 0;
120	rel.tv_nsec = 0;
121	rel = timespec_add(rel, ns);
122	target = timespec_add(now, ns);
123	clock_nanosleep(clockid, 0, &rel, NULL);
124	clock_gettime(clockid, &now);
125
126	if (!in_order(target, now))
127		return -1;
128	return 0;
129}
130
131int main(int argc, char **argv)
132{
133	long long length;
134	int clockid, ret;
135
136	for (clockid = CLOCK_REALTIME; clockid < NR_CLOCKIDS; clockid++) {
137
138		/* Skip cputime clockids since nanosleep won't increment cputime */
139		if (clockid == CLOCK_PROCESS_CPUTIME_ID ||
140				clockid == CLOCK_THREAD_CPUTIME_ID ||
141				clockid == CLOCK_HWSPECIFIC)
142			continue;
143
144		printf("Nanosleep %-31s ", clockstring(clockid));
145
146		length = 10;
147		while (length <= (NSEC_PER_SEC * 10)) {
148			ret = nanosleep_test(clockid, length);
149			if (ret == UNSUPPORTED) {
150				printf("[UNSUPPORTED]\n");
151				goto next;
152			}
153			if (ret < 0) {
154				printf("[FAILED]\n");
155				return ksft_exit_fail();
156			}
157			length *= 100;
158		}
159		printf("[OK]\n");
160next:
161		ret = 0;
162	}
163	return ksft_exit_pass();
164}
165