selftests: Add futex functional tests

The futextest testsuite [1] provides functional, stress, and
performance tests for the various futex op codes. Those tests will be of
more use to futex developers if they are included with the kernel
source.

Copy the core infrastructure and the functional tests into selftests,
but adapt them for inclusion in the kernel:

- Update the Makefile to include the run_tests target, remove reference
  to the performance and stress tests from the contributed sources.
- Replace my dead IBM email address with my current Intel email address.
- Remove the warrantee and write-to paragraphs from the license blurbs.
- Remove the NAME section as the filename is easily determined. ;-)
- Make the whitespace usage consistent in a couple of places.
- Cleanup various CodingStyle violations.

A future effort will explore moving the performance and stress tests
into the kernel.

1. http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: linux-api@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

1 files changed, 409 insertions, 0 deletions

diff --git a/tools/testing/selftests/futex/functional/futex_requeue_pi.c b/tools/testing/selftests/futex/functional/futex_requeue_pi.c
new file mode 100644
index 000000000000..3da06ad23996
--- /dev/null
+++ b/tools/testing/selftests/futex/functional/futex_requeue_pi.c
@@ -0,0 +1,409 @@
+/******************************************************************************
+ *
+ *   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 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);
+		}
+	}
+
+	printf("%s: Test requeue functionality\n", basename(argv[0]));
+	printf("\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(ret);
+	return ret;
+}