Add compiler barriers to read-side for mutex ordering

[userspace-rcu.git] / tests / test_urcu_lfs.c

/*
 * test_urcu_lfs.c
 *
 * Userspace RCU library - example RCU-based lock-free stack
 *
 * Copyright February 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 * Copyright February 2010 - Paolo Bonzini <pbonzini@redhat.com>
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _GNU_SOURCE
#include "../config.h"
#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <assert.h>
#include <sys/syscall.h>
#include <sched.h>
#include <errno.h>

#include <urcu/arch.h>

/* hardcoded number of CPUs */
#define NR_CPUS 16384

#if defined(_syscall0)
_syscall0(pid_t, gettid)
#elif defined(__NR_gettid)
static inline pid_t gettid(void)
{
	return syscall(__NR_gettid);
}
#else
#warning "use pid as tid"
static inline pid_t gettid(void)
{
	return getpid();
}
#endif

#ifndef DYNAMIC_LINK_TEST
#define _LGPL_SOURCE
#endif
#include <urcu.h>
#include <urcu/rculfstack.h>
#include <urcu-defer.h>

static volatile int test_go, test_stop;

static unsigned long rduration;

static unsigned long duration;

/* read-side C.S. duration, in loops */
static unsigned long wdelay;

static inline void loop_sleep(unsigned long l)
{
	while(l-- != 0)
		cpu_relax();
}

static int verbose_mode;

#define printf_verbose(fmt, args...)		\
	do {					\
		if (verbose_mode)		\
			printf(fmt, args);	\
	} while (0)

static unsigned int cpu_affinities[NR_CPUS];
static unsigned int next_aff = 0;
static int use_affinity = 0;

pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;

#ifndef HAVE_CPU_SET_T
typedef unsigned long cpu_set_t;
# define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
# define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
#endif

static void set_affinity(void)
{
	cpu_set_t mask;
	int cpu;
	int ret;

	if (!use_affinity)
		return;

#if HAVE_SCHED_SETAFFINITY
	ret = pthread_mutex_lock(&affinity_mutex);
	if (ret) {
		perror("Error in pthread mutex lock");
		exit(-1);
	}
	cpu = cpu_affinities[next_aff++];
	ret = pthread_mutex_unlock(&affinity_mutex);
	if (ret) {
		perror("Error in pthread mutex unlock");
		exit(-1);
	}

	CPU_ZERO(&mask);
	CPU_SET(cpu, &mask);
#if SCHED_SETAFFINITY_ARGS == 2
	sched_setaffinity(0, &mask);
#else
	sched_setaffinity(0, sizeof(mask), &mask);
#endif
#endif /* HAVE_SCHED_SETAFFINITY */
}

/*
 * returns 0 if test should end.
 */
static int test_duration_dequeue(void)
{
	return !test_stop;
}

static int test_duration_enqueue(void)
{
	return !test_stop;
}

static unsigned long long __thread nr_dequeues;
static unsigned long long __thread nr_enqueues;

static unsigned long long __thread nr_successful_dequeues;
static unsigned long long __thread nr_successful_enqueues;

static unsigned int nr_enqueuers;
static unsigned int nr_dequeuers;

static struct rcu_lfs_stack s;

void *thr_enqueuer(void *_count)
{
	unsigned long long *count = _count;

	printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
			"enqueuer", pthread_self(), (unsigned long)gettid());

	set_affinity();

	rcu_register_thread();

	while (!test_go)
	{
	}
	smp_mb();

	for (;;) {
		struct rcu_lfs_node *node = malloc(sizeof(*node));
		if (!node)
			goto fail;
		rcu_lfs_node_init(node);
		rcu_lfs_push(&s, node);
		nr_successful_enqueues++;

		if (unlikely(wdelay))
			loop_sleep(wdelay);
fail:
		nr_enqueues++;
		if (unlikely(!test_duration_enqueue()))
			break;
	}

	rcu_unregister_thread();

	count[0] = nr_enqueues;
	count[1] = nr_successful_enqueues;
	printf_verbose("enqueuer thread_end, thread id : %lx, tid %lu, "
		       "enqueues %llu successful_enqueues %llu\n",
		       pthread_self(), (unsigned long)gettid(), nr_enqueues,
		       nr_successful_enqueues);
	return ((void*)1);

}

void *thr_dequeuer(void *_count)
{
	unsigned long long *count = _count;

	printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
			"dequeuer", pthread_self(), (unsigned long)gettid());

	set_affinity();

	rcu_defer_register_thread();
	rcu_register_thread();

	while (!test_go)
	{
	}
	smp_mb();

	for (;;) {
		struct rcu_lfs_node *node = rcu_lfs_pop(&s);

		if (node) {
			defer_rcu(free, node);
			nr_successful_dequeues++;
		}

		nr_dequeues++;
		if (unlikely(!test_duration_dequeue()))
			break;
		if (unlikely(rduration))
			loop_sleep(rduration);
	}

	rcu_unregister_thread();
	rcu_defer_unregister_thread();

	printf_verbose("dequeuer thread_end, thread id : %lx, tid %lu, "
		       "dequeues %llu, successful_dequeues %llu\n",
		       pthread_self(), (unsigned long)gettid(), nr_dequeues,
		       nr_successful_dequeues);
	count[0] = nr_dequeues;
	count[1] = nr_successful_dequeues;
	return ((void*)2);
}

void test_end(struct rcu_lfs_stack *s, unsigned long long *nr_dequeues)
{
	struct rcu_lfs_node *node;

	do {
		node = rcu_lfs_pop(s);
		if (node) {
			free(node);
			(*nr_dequeues)++;
		}
	} while (node);
}

void show_usage(int argc, char **argv)
{
	printf("Usage : %s nr_dequeuers nr_enqueuers duration (s)", argv[0]);
	printf(" [-d delay] (enqueuer period (in loops))");
	printf(" [-c duration] (dequeuer period (in loops))");
	printf(" [-v] (verbose output)");
	printf(" [-a cpu#] [-a cpu#]... (affinity)");
	printf("\n");
}

int main(int argc, char **argv)
{
	int err;
	pthread_t *tid_enqueuer, *tid_dequeuer;
	void *tret;
	unsigned long long *count_enqueuer, *count_dequeuer;
	unsigned long long tot_enqueues = 0, tot_dequeues = 0;
	unsigned long long tot_successful_enqueues = 0,
			   tot_successful_dequeues = 0;
	unsigned long long end_dequeues = 0;
	int i, a;

	if (argc < 4) {
		show_usage(argc, argv);
		return -1;
	}

	err = sscanf(argv[1], "%u", &nr_dequeuers);
	if (err != 1) {
		show_usage(argc, argv);
		return -1;
	}

	err = sscanf(argv[2], "%u", &nr_enqueuers);
	if (err != 1) {
		show_usage(argc, argv);
		return -1;
	}
	
	err = sscanf(argv[3], "%lu", &duration);
	if (err != 1) {
		show_usage(argc, argv);
		return -1;
	}

	for (i = 4; i < argc; i++) {
		if (argv[i][0] != '-')
			continue;
		switch (argv[i][1]) {
		case 'a':
			if (argc < i + 2) {
				show_usage(argc, argv);
				return -1;
			}
			a = atoi(argv[++i]);
			cpu_affinities[next_aff++] = a;
			use_affinity = 1;
			printf_verbose("Adding CPU %d affinity\n", a);
			break;
		case 'c':
			if (argc < i + 2) {
				show_usage(argc, argv);
				return -1;
			}
			rduration = atol(argv[++i]);
			break;
		case 'd':
			if (argc < i + 2) {
				show_usage(argc, argv);
				return -1;
			}
			wdelay = atol(argv[++i]);
			break;
		case 'v':
			verbose_mode = 1;
			break;
		}
	}

	printf_verbose("running test for %lu seconds, %u enqueuers, "
		       "%u dequeuers.\n",
		       duration, nr_enqueuers, nr_dequeuers);
	printf_verbose("Writer delay : %lu loops.\n", rduration);
	printf_verbose("Reader duration : %lu loops.\n", wdelay);
	printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
			"main", pthread_self(), (unsigned long)gettid());

	tid_enqueuer = malloc(sizeof(*tid_enqueuer) * nr_enqueuers);
	tid_dequeuer = malloc(sizeof(*tid_dequeuer) * nr_dequeuers);
	count_enqueuer = malloc(2 * sizeof(*count_enqueuer) * nr_enqueuers);
	count_dequeuer = malloc(2 * sizeof(*count_dequeuer) * nr_dequeuers);
	rcu_lfs_init(&s);

	next_aff = 0;

	for (i = 0; i < nr_enqueuers; i++) {
		err = pthread_create(&tid_enqueuer[i], NULL, thr_enqueuer,
				     &count_enqueuer[2 * i]);
		if (err != 0)
			exit(1);
	}
	for (i = 0; i < nr_dequeuers; i++) {
		err = pthread_create(&tid_dequeuer[i], NULL, thr_dequeuer,
				     &count_dequeuer[2 * i]);
		if (err != 0)
			exit(1);
	}

	smp_mb();

	test_go = 1;

	for (i = 0; i < duration; i++) {
		sleep(1);
		if (verbose_mode)
			write (1, ".", 1);
	}

	test_stop = 1;

	for (i = 0; i < nr_enqueuers; i++) {
		err = pthread_join(tid_enqueuer[i], &tret);
		if (err != 0)
			exit(1);
		tot_enqueues += count_enqueuer[2 * i];
		tot_successful_enqueues += count_enqueuer[2 * i + 1];
	}
	for (i = 0; i < nr_dequeuers; i++) {
		err = pthread_join(tid_dequeuer[i], &tret);
		if (err != 0)
			exit(1);
		tot_dequeues += count_dequeuer[2 * i];
		tot_successful_dequeues += count_dequeuer[2 * i + 1];
	}
	
	test_end(&s, &end_dequeues);

	printf_verbose("total number of enqueues : %llu, dequeues %llu\n",
		       tot_enqueues, tot_dequeues);
	printf_verbose("total number of successful enqueues : %llu, "
		       "successful dequeues %llu\n",
		       tot_successful_enqueues, tot_successful_dequeues);
	printf("SUMMARY %-25s testdur %4lu nr_enqueuers %3u wdelay %6lu "
		"nr_dequeuers %3u "
		"rdur %6lu nr_enqueues %12llu nr_dequeues %12llu "
		"successful enqueues %12llu successful dequeues %12llu "
		"end_dequeues %llu nr_ops %12llu\n",
		argv[0], duration, nr_enqueuers, wdelay,
		nr_dequeuers, rduration, tot_enqueues, tot_dequeues,
		tot_successful_enqueues,
		tot_successful_dequeues, end_dequeues,
		tot_enqueues + tot_dequeues);
	if (tot_successful_enqueues != tot_successful_dequeues + end_dequeues)
		printf("WARNING! Discrepancy between nr succ. enqueues %llu vs "
		       "succ. dequeues + end dequeues %llu.\n",
		       tot_successful_enqueues,
		       tot_successful_dequeues + end_dequeues);

	free(count_enqueuer);
	free(count_dequeuer);
	free(tid_enqueuer);
	free(tid_dequeuer);
	return 0;
}