/*
* rcuq_test.c
*
* usage: rcuq_test <readers> <duration>
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (c) 2013 Mike D. Day, IBM Corporation.
*/
#include "qemu/osdep.h"
#include "qemu/atomic.h"
#include "qemu/rcu.h"
#include "qemu/thread.h"
#include "qemu/rcu_queue.h"
/*
* Test variables.
*/
static QemuMutex counts_mutex;
static long long n_reads = 0LL;
static long long n_updates = 0LL;
static long long n_reclaims = 0LL;
static long long n_nodes_removed = 0LL;
static long long n_nodes = 0LL;
static int g_test_in_charge = 0;
static int nthreadsrunning;
#define GOFLAG_INIT 0
#define GOFLAG_RUN 1
#define GOFLAG_STOP 2
static volatile int goflag = GOFLAG_INIT;
#define RCU_READ_RUN 1000
#define RCU_UPDATE_RUN 10
#define NR_THREADS 100
#define RCU_Q_LEN 100
static QemuThread threads[NR_THREADS];
static struct rcu_reader_data *data[NR_THREADS];
static int n_threads;
static int select_random_el(int max)
{
return (rand() % max);
}
static void create_thread(void *(*func)(void *))
{
if (n_threads >= NR_THREADS) {
fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS);
exit(-1);
}
qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads],
QEMU_THREAD_JOINABLE);
n_threads++;
}
static void wait_all_threads(void)
{
int i;
for (i = 0; i < n_threads; i++) {
qemu_thread_join(&threads[i]);
}
n_threads = 0;
}
struct list_element {
QLIST_ENTRY(list_element) entry;
struct rcu_head rcu;
};
static void reclaim_list_el(struct rcu_head *prcu)
{
struct list_element *el = container_of(prcu, struct list_element, rcu);
g_free(el);
/* Accessed only from call_rcu thread. */
n_reclaims++;
}
static QLIST_HEAD(q_list_head, list_element) Q_list_head;
static void *rcu_q_reader(void *arg)
{
long long n_reads_local = 0;
struct list_element *el;
rcu_register_thread();
*(struct rcu_reader_data **)arg = &rcu_reader;
atomic_inc(&nthreadsrunning);
while (goflag == GOFLAG_INIT) {
g_usleep(1000);
}
while (goflag == GOFLAG_RUN) {
rcu_read_lock();
QLIST_FOREACH_RCU(el, &Q_list_head, entry) {
n_reads_local++;
if (goflag == GOFLAG_STOP) {
break;
}
}
rcu_read_unlock();
g_usleep(100);
}
qemu_mutex_lock(&counts_mutex);
n_reads += n_reads_local;
qemu_mutex_unlock(&counts_mutex);
rcu_unregister_thread();
return NULL;
}
static void *rcu_q_updater(void *arg)
{
int j, target_el;
long long n_nodes_local = 0;
long long n_updates_local = 0;
long long n_removed_local = 0;
struct list_element *el, *prev_el;
*(struct rcu_reader_data **)arg = &rcu_reader;
atomic_inc(&nthreadsrunning);
while (goflag == GOFLAG_INIT) {
g_usleep(1000);
}
while (goflag == GOFLAG_RUN) {
target_el = select_random_el(RCU_Q_LEN);
j = 0;
/* FOREACH_RCU could work here but let's use both macros */
QLIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
j++;
if (target_el == j) {
QLIST_REMOVE_RCU(prev_el, entry);
/* may be more than one updater in the future */
call_rcu1(&prev_el->rcu, reclaim_list_el);
n_removed_local++;
break;
}
}
if (goflag == GOFLAG_STOP) {
break;
}
target_el = select_random_el(RCU_Q_LEN);
j = 0;
QLIST_FOREACH_RCU(el, &Q_list_head, entry) {
j++;
if (target_el == j) {
prev_el = g_new(struct list_element, 1);
n_nodes += n_nodes_local;
QLIST_INSERT_BEFORE_RCU(el, prev_el, entry);
break;
}
}
n_updates_local += 2;
synchronize_rcu();
}
synchronize_rcu();
qemu_mutex_lock(&counts_mutex);
n_nodes += n_nodes_local;
n_updates += n_updates_local;
n_nodes_removed += n_removed_local;
qemu_mutex_unlock(&counts_mutex);
return NULL;
}
static void rcu_qtest_init(void)
{
struct list_element *new_el;
int i;
nthreadsrunning = 0;
srand(time(0));
for (i = 0; i < RCU_Q_LEN; i++) {
new_el = g_new(struct list_element, 1);
QLIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
}
qemu_mutex_lock(&counts_mutex);
n_nodes += RCU_Q_LEN;
qemu_mutex_unlock(&counts_mutex);
}
static void rcu_qtest_run(int duration, int nreaders)
{
int nthreads = nreaders + 1;
while (atomic_read(&nthreadsrunning) < nthreads) {
g_usleep(1000);
}
goflag = GOFLAG_RUN;
sleep(duration);
goflag = GOFLAG_STOP;
wait_all_threads();
}
static void rcu_qtest(const char *test, int duration, int nreaders)
{
int i;
long long n_removed_local = 0;
struct list_element *el, *prev_el;
rcu_qtest_init();
for (i = 0; i < nreaders; i++) {
create_thread(rcu_q_reader);
}
create_thread(rcu_q_updater);
rcu_qtest_run(duration, nreaders);
QLIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
QLIST_REMOVE_RCU(prev_el, entry);
call_rcu1(&prev_el->rcu, reclaim_list_el);
n_removed_local++;
}
qemu_mutex_lock(&counts_mutex);
n_nodes_removed += n_removed_local;
qemu_mutex_unlock(&counts_mutex);
synchronize_rcu();
while (n_nodes_removed > n_reclaims) {
g_usleep(100);
synchronize_rcu();
}
if (g_test_in_charge) {
g_assert_cmpint(n_nodes_removed, ==, n_reclaims);
} else {
printf("%s: %d readers; 1 updater; nodes read: " \
"%lld, nodes removed: %lld; nodes reclaimed: %lld\n",
test, nthreadsrunning - 1, n_reads, n_nodes_removed, n_reclaims);
exit(0);
}
}
static void usage(int argc, char *argv[])
{
fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
exit(-1);
}
static int gtest_seconds;
static void gtest_rcuq_one(void)
{
rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
}
static void gtest_rcuq_few(void)
{
rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
}
static void gtest_rcuq_many(void)
{
rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
}
int main(int argc, char *argv[])
{
int duration = 0, readers = 0;
qemu_mutex_init(&counts_mutex);
if (argc >= 2) {
if (argv[1][0] == '-') {
g_test_init(&argc, &argv, NULL);
if (g_test_quick()) {
gtest_seconds = 4;
} else {
gtest_seconds = 20;
}
g_test_add_func("/rcu/qlist/single-threaded", gtest_rcuq_one);
g_test_add_func("/rcu/qlist/short-few", gtest_rcuq_few);
g_test_add_func("/rcu/qlist/long-many", gtest_rcuq_many);
g_test_in_charge = 1;
return g_test_run();
}
duration = strtoul(argv[1], NULL, 0);
}
if (argc >= 3) {
readers = strtoul(argv[2], NULL, 0);
}
if (duration && readers) {
rcu_qtest(argv[0], duration, readers);
return 0;
}
usage(argc, argv);
return -1;
}
