/******************************************************************************
*
* Copyright © International Business Machines Corp., 2006-2008
*
* 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.
*
* DESCRIPTION
* This test excercises the futex syscall op codes needed for requeuing
* priority inheritance aware POSIX condition variables and mutexes.
*
* AUTHORS
* Sripathi Kodi <sripathik@in.ibm.com>
* Darren Hart <dvhart@linux.intel.com>
*
* HISTORY
* 2008-Jan-13: Initial version by Sripathi Kodi <sripathik@in.ibm.com>
* 2009-Nov-6: futex test adaptation by Darren Hart <dvhart@linux.intel.com>
*
*****************************************************************************/
#include <errno.h>
#include <limits.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include "atomic.h"
#include "futextest.h"
#include "logging.h"
#define TEST_NAME "futex-requeue-pi"
#define MAX_WAKE_ITERS 1000
#define THREAD_MAX 10
#define SIGNAL_PERIOD_US 100
atomic_t waiters_blocked = ATOMIC_INITIALIZER;
atomic_t waiters_woken = ATOMIC_INITIALIZER;
futex_t f1 = FUTEX_INITIALIZER;
futex_t f2 = FUTEX_INITIALIZER;
futex_t wake_complete = FUTEX_INITIALIZER;
/* Test option defaults */
static long timeout_ns;
static int broadcast;
static int owner;
static int locked;
struct thread_arg {
long id;
struct timespec *timeout;
int lock;
int ret;
};
#define THREAD_ARG_INITIALIZER { 0, NULL, 0, 0 }
void usage(char *prog)
{
printf("Usage: %s\n", prog);
printf(" -b Broadcast wakeup (all waiters)\n");
printf(" -c Use color\n");
printf(" -h Display this help message\n");
printf(" -l Lock the pi futex across requeue\n");
printf(" -o Use a third party pi futex owner during requeue (cancels -l)\n");
printf(" -t N Timeout in nanoseconds (default: 0)\n");
printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
VQUIET, VCRITICAL, VINFO);
}
int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg,
int policy, int prio)
{
int ret;
struct sched_param schedp;
pthread_attr_t attr;
pthread_attr_init(&attr);
memset(&schedp, 0, sizeof(schedp));
ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
if (ret) {
error("pthread_attr_setinheritsched\n", ret);
return -1;
}
ret = pthread_attr_setschedpolicy(&attr, policy);
if (ret) {
error("pthread_attr_setschedpolicy\n", ret);
return -1;
}
schedp.sched_priority = prio;
ret = pthread_attr_setschedparam(&attr, &schedp);
if (ret) {
error("pthread_attr_setschedparam\n", ret);
return -1;
}
ret = pthread_create(pth, &attr, func, arg);
if (ret) {
error("pthread_create\n", ret);
return -1;
}
return 0;
}
void *waiterfn(void *arg)
{
struct thread_arg *args = (struct thread_arg *)arg;
futex_t old_val;
info("Waiter %ld: running\n", args->id);
/* Each thread sleeps for a different amount of time
* This is to avoid races, because we don't lock the
* external mutex here */
usleep(1000 * (long)args->id);
old_val = f1;
atomic_inc(&waiters_blocked);
info("Calling futex_wait_requeue_pi: %p (%u) -> %p\n",
&f1, f1, &f2);
args->ret = futex_wait_requeue_pi(&f1, old_val, &f2, args->timeout,
FUTEX_PRIVATE_FLAG);
info("waiter %ld woke with %d %s\n", args->id, args->ret,
args->ret < 0 ? strerror(errno) : "");
atomic_inc(&waiters_woken);
if (args->ret < 0) {
if (args->timeout && errno == ETIMEDOUT)
args->ret = 0;
else {
args->ret = RET_ERROR;
error("futex_wait_requeue_pi\n", errno);
}
futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
}
futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
info("Waiter %ld: exiting with %d\n", args->id, args->ret);
pthread_exit((void *)&args->ret);
}
void *broadcast_wakerfn(void *arg)
{
struct thread_arg *args = (struct thread_arg *)arg;
int nr_requeue = INT_MAX;
int task_count = 0;
futex_t old_val;
int nr_wake = 1;
int i = 0;
info("Waker: waiting for waiters to block\n");
while (waiters_blocked.val < THREAD_MAX)
usleep(1000);
usleep(1000);
info("Waker: Calling broadcast\n");
if (args->lock) {
info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n", f2, &f2);
futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
}
continue_requeue:
old_val = f1;
args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2, nr_wake, nr_requeue,
FUTEX_PRIVATE_FLAG);
if (args->ret < 0) {
args->ret = RET_ERROR;
error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
} else if (++i < MAX_WAKE_ITERS) {
task_count += args->ret;
if (task_count < THREAD_MAX - waiters_woken.val)
goto continue_requeue;
} else {
error("max broadcast iterations (%d) reached with %d/%d tasks woken or requeued\n",
0, MAX_WAKE_ITERS, task_count, THREAD_MAX);
args->ret = RET_ERROR;
}
futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
if (args->lock)
futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
if (args->ret > 0)
args->ret = task_count;
info("Waker: exiting with %d\n", args->ret);
pthread_exit((void *)&args->ret);
}
void *signal_wakerfn(void *arg)
{
struct thread_arg *args = (struct thread_arg *)arg;
unsigned int old_val;
int nr_requeue = 0;
int task_count = 0;
int nr_wake = 1;
int i = 0;
info("Waker: waiting for waiters to block\n");
while (waiters_blocked.val < THREAD_MAX)
usleep(1000);
usleep(1000);
while (task_count < THREAD_MAX && waiters_woken.val < THREAD_MAX) {
info("task_count: %d, waiters_woken: %d\n",
task_count, waiters_woken.val);
if (args->lock) {
info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n",
f2, &f2);
futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
}
info("Waker: Calling signal\n");
/* cond_signal */
old_val = f1;
args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2,
nr_wake, nr_requeue,
FUTEX_PRIVATE_FLAG);
if (args->ret < 0)
args->ret = -errno;
info("futex: %x\n", f2);
if (args->lock) {
info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n",
f2, &f2);
futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
}
info("futex: %x\n", f2);
if (args->ret < 0) {
error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
args->ret = RET_ERROR;
break;
}
task_count += args->ret;
usleep(SIGNAL_PERIOD_US);
i++;
/* we have to loop at least THREAD_MAX times */
if (i > MAX_WAKE_ITERS + THREAD_MAX) {
error("max signaling iterations (%d) reached, giving up on pending waiters.\n",
0, MAX_WAKE_ITERS + THREAD_MAX);
args->ret = RET_ERROR;
break;
}
}
futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
if (args->ret >= 0)
args->ret = task_count;
info("Waker: exiting with %d\n", args->ret);
info("Waker: waiters_woken: %d\n", waiters_woken.val);
pthread_exit((void *)&args->ret);
}
void *third_party_blocker(void *arg)
{
struct thread_arg *args = (struct thread_arg *)arg;
int ret2 = 0;
args->ret = futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
if (args->ret)
goto out;
args->ret = futex_wait(&wake_complete, wake_complete, NULL,
FUTEX_PRIVATE_FLAG);
ret2 = futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
out:
if (args->ret || ret2) {
error("third_party_blocker() futex error", 0);
args->ret = RET_ERROR;
}
pthread_exit((void *)&args->ret);
}
int unit_test(int broadcast, long lock, int third_party_owner, long timeout_ns)
{
void *(*wakerfn)(void *) = signal_wakerfn;
struct thread_arg blocker_arg = THREAD_ARG_INITIALIZER;
struct thread_arg waker_arg = THREAD_ARG_INITIALIZER;
pthread_t waiter[THREAD_MAX], waker, blocker;
struct timespec ts, *tsp = NULL;
struct thread_arg args[THREAD_MAX];
int *waiter_ret;
int i, ret = RET_PASS;
if (timeout_ns) {
time_t secs;
info("timeout_ns = %ld\n", timeout_ns);
ret = clock_gettime(CLOCK_MONOTONIC, &ts);
secs = (ts.tv_nsec + timeout_ns) / 1000000000;
ts.tv_nsec = ((int64_t)ts.tv_nsec + timeout_ns) % 1000000000;
ts.tv_sec += secs;
info("ts.tv_sec = %ld\n", ts.tv_sec);
info("ts.tv_nsec = %ld\n", ts.tv_nsec);
tsp = &ts;
}
if (broadcast)
wakerfn = broadcast_wakerfn;
if (third_party_owner) {
if (create_rt_thread(&blocker, third_party_blocker,
(void *)&blocker_arg, SCHED_FIFO, 1)) {
error("Creating third party blocker thread failed\n",
errno);
ret = RET_ERROR;
goto out;
}
}
atomic_set(&waiters_woken, 0);
for (i = 0; i < THREAD_MAX; i++) {
args[i].id = i;
args[i].timeout = tsp;
info("Starting thread %d\n", i);
if (create_rt_thread(&waiter[i], waiterfn, (void *)&args[i],
SCHED_FIFO, 1)) {
error("Creating waiting thread failed\n", errno);
ret = RET_ERROR;
goto out;
}
}
waker_arg.lock = lock;
if (create_rt_thread(&waker, wakerfn, (void *)&waker_arg,
SCHED_FIFO, 1)) {
error("Creating waker thread failed\n", errno);
ret = RET_ERROR;
goto out;
}
/* Wait for threads to finish */
/* Store the first error or failure encountered in waiter_ret */
waiter_ret = &args[0].ret;
for (i = 0; i < THREAD_MAX; i++)
pthread_join(waiter[i],
*waiter_ret ? NULL : (void **)&waiter_ret);
if (third_party_owner)
pthread_join(blocker, NULL);
pthread_join(waker, NULL);
out:
if (!ret) {
if (*waiter_ret)
ret = *waiter_ret;
else if (waker_arg.ret < 0)
ret = waker_arg.ret;
else if (blocker_arg.ret)
ret = blocker_arg.ret;
}
return ret;
}
int main(int argc, char *argv[])
{
int c, ret;
while ((c = getopt(argc, argv, "bchlot:v:")) != -1) {
switch (c) {
case 'b':
broadcast = 1;
break;
case 'c':
log_color(1);
break;
case 'h':
usage(basename(argv[0]));
exit(0);
case 'l':
locked = 1;
break;
case 'o':
owner = 1;
locked = 0;
break;
case 't':
timeout_ns = atoi(optarg);
break;
case 'v':
log_verbosity(atoi(optarg));
break;
default:
usage(basename(argv[0]));
exit(1);
}
}
ksft_print_header();
ksft_print_msg("%s: Test requeue functionality\n", basename(argv[0]));
ksft_print_msg(
"\tArguments: broadcast=%d locked=%d owner=%d timeout=%ldns\n",
broadcast, locked, owner, timeout_ns);
/*
* FIXME: unit_test is obsolete now that we parse options and the
* various style of runs are done by run.sh - simplify the code and move
* unit_test into main()
*/
ret = unit_test(broadcast, locked, owner, timeout_ns);
print_result(TEST_NAME, ret);
return ret;
}