thloop.c

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#include <pthread.h>
 3#include <stdlib.h>
 4#include <signal.h>
 5#include <unistd.h>
 6#include <linux/compiler.h>
 7#include "../tests.h"
 8
 9static volatile sig_atomic_t done;
10
11/* We want to check this symbol in perf report */
12noinline void test_loop(void);
13
14static void sighandler(int sig __maybe_unused)
15{
16	done = 1;
17}
18
19noinline void test_loop(void)
20{
21	while (!done);
22}
23
24static void *thfunc(void *arg)
25{
26	void (*loop_fn)(void) = arg;
27
28	loop_fn();
29	return NULL;
30}
31
32static int thloop(int argc, const char **argv)
33{
34	int nt = 2, sec = 1, err = 1;
35	pthread_t *thread_list = NULL;
36
37	if (argc > 0)
38		sec = atoi(argv[0]);
39
40	if (sec <= 0) {
41		fprintf(stderr, "Error: seconds (%d) must be >= 1\n", sec);
42		return 1;
43	}
44
45	if (argc > 1)
46		nt = atoi(argv[1]);
47
48	if (nt <= 0) {
49		fprintf(stderr, "Error: thread count (%d) must be >= 1\n", nt);
50		return 1;
51	}
52
53	signal(SIGINT, sighandler);
54	signal(SIGALRM, sighandler);
55
56	thread_list = calloc(nt, sizeof(pthread_t));
57	if (thread_list == NULL) {
58		fprintf(stderr, "Error: malloc failed for %d threads\n", nt);
59		goto out;
60	}
61	for (int i = 1; i < nt; i++) {
62		int ret = pthread_create(&thread_list[i], NULL, thfunc, test_loop);
63
64		if (ret) {
65			fprintf(stderr, "Error: failed to create thread %d\n", i);
66			done = 1; // Ensure started threads terminate.
67			goto out;
68		}
69	}
70	alarm(sec);
71	test_loop();
72	err = 0;
73out:
74	for (int i = 1; i < nt; i++) {
75		if (thread_list && thread_list[i])
76			pthread_join(thread_list[i], /*retval=*/NULL);
77	}
78	free(thread_list);
79	return err;
80}
81
82DEFINE_WORKLOAD(thloop);