// SPDX-License-Identifier: GPL-2.0-or-later
/******************************************************************************
 *
 *   Copyright © International Business Machines  Corp., 2006-2008
 *
 * 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>
 *
 *****************************************************************************/

#define _GNU_SOURCE

#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 "kselftest_harness.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;

struct thread_arg {
        long id;
        struct timespec *timeout;
        int lock;
        int ret;
};
#define THREAD_ARG_INITIALIZER { 0, NULL, 0, 0 }

FIXTURE(args)
{
};

FIXTURE_SETUP(args)
{
};

FIXTURE_TEARDOWN(args)
{
};

FIXTURE_VARIANT(args)
{
        long timeout_ns;
        bool broadcast;
        bool owner;
        bool locked;
};

/*
 * For a given timeout value, this macro creates a test input with all the
 * possible combinations of valid arguments
 */
#define FIXTURE_VARIANT_ADD_TIMEOUT(timeout)            \
                                                        \
FIXTURE_VARIANT_ADD(args, t_##timeout)                  \
{                                                       \
        .timeout_ns = timeout,                          \
};                                                      \
                                                        \
FIXTURE_VARIANT_ADD(args, t_##timeout##_broadcast)      \
{                                                       \
        .timeout_ns = timeout,                          \
        .broadcast = true,                              \
};                                                      \
                                                        \
FIXTURE_VARIANT_ADD(args, t_##timeout##_broadcast_locked) \
{                                                       \
        .timeout_ns = timeout,                          \
        .broadcast = true,                              \
        .locked = true,                                 \
};                                                      \
                                                        \
FIXTURE_VARIANT_ADD(args, t_##timeout##_broadcast_owner) \
{                                                       \
        .timeout_ns = timeout,                          \
        .broadcast = true,                              \
        .owner = true,                                  \
};                                                      \
                                                        \
FIXTURE_VARIANT_ADD(args, t_##timeout##_locked)         \
{                                                       \
        .timeout_ns = timeout,                          \
        .locked = true,                                 \
};                                                      \
                                                        \
FIXTURE_VARIANT_ADD(args, t_##timeout##_owner)          \
{                                                       \
        .timeout_ns = timeout,                          \
        .owner = true,                                  \
};                                                      \

FIXTURE_VARIANT_ADD_TIMEOUT(0);
FIXTURE_VARIANT_ADD_TIMEOUT(5000);
FIXTURE_VARIANT_ADD_TIMEOUT(500000);
FIXTURE_VARIANT_ADD_TIMEOUT(2000000000);

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) {
                ksft_exit_fail_msg("pthread_attr_setinheritsched\n");
                return -1;
        }

        ret = pthread_attr_setschedpolicy(&attr, policy);
        if (ret) {
                ksft_exit_fail_msg("pthread_attr_setschedpolicy\n");
                return -1;
        }

        schedp.sched_priority = prio;
        ret = pthread_attr_setschedparam(&attr, &schedp);
        if (ret) {
                ksft_exit_fail_msg("pthread_attr_setschedparam\n");
                return -1;
        }

        ret = pthread_create(pth, &attr, func, arg);
        if (ret) {
                ksft_exit_fail_msg("pthread_create\n");
                return -1;
        }
        return 0;
}


void *waiterfn(void *arg)
{
        struct thread_arg *args = (struct thread_arg *)arg;
        futex_t old_val;

        ksft_print_dbg_msg("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);
        ksft_print_dbg_msg("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);

        ksft_print_dbg_msg("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 {
                        ksft_exit_fail_msg("futex_wait_requeue_pi\n");
                }
                futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
        }
        futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);

        ksft_print_dbg_msg("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;

        ksft_print_dbg_msg("Waker: waiting for waiters to block\n");
        while (waiters_blocked.val < THREAD_MAX)
                usleep(1000);
        usleep(1000);

        ksft_print_dbg_msg("Waker: Calling broadcast\n");
        if (args->lock) {
                ksft_print_dbg_msg("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) {
                ksft_exit_fail_msg("FUTEX_CMP_REQUEUE_PI failed\n");
        } else if (++i < MAX_WAKE_ITERS) {
                task_count += args->ret;
                if (task_count < THREAD_MAX - waiters_woken.val)
                        goto continue_requeue;
        } else {
                ksft_exit_fail_msg("max broadcast iterations (%d) reached with %d/%d tasks woken or requeued\n",
                       MAX_WAKE_ITERS, task_count, THREAD_MAX);
        }

        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;

        ksft_print_dbg_msg("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;

        ksft_print_dbg_msg("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) {
                ksft_print_dbg_msg("task_count: %d, waiters_woken: %d\n",
                     task_count, waiters_woken.val);
                if (args->lock) {
                        ksft_print_dbg_msg("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n",
                            f2, &f2);
                        futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
                }
                ksft_print_dbg_msg("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;
                ksft_print_dbg_msg("futex: %x\n", f2);
                if (args->lock) {
                        ksft_print_dbg_msg("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n",
                            f2, &f2);
                        futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
                }
                ksft_print_dbg_msg("futex: %x\n", f2);
                if (args->ret < 0)
                        ksft_exit_fail_msg("FUTEX_CMP_REQUEUE_PI failed\n");

                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) {
                        ksft_exit_fail_msg("max signaling iterations (%d) reached, giving up on pending waiters.\n",
                              MAX_WAKE_ITERS + THREAD_MAX);
                }
        }

        futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);

        if (args->ret >= 0)
                args->ret = task_count;

        ksft_print_dbg_msg("Waker: exiting with %d\n", args->ret);
        ksft_print_dbg_msg("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)
                ksft_exit_fail_msg("third_party_blocker() futex error");

        pthread_exit((void *)&args->ret);
}

TEST_F(args, futex_requeue_pi)
{
        struct thread_arg blocker_arg = THREAD_ARG_INITIALIZER;
        struct thread_arg waker_arg = THREAD_ARG_INITIALIZER;
        pthread_t waiter[THREAD_MAX], waker, blocker;
        void *(*wakerfn)(void *) = signal_wakerfn;
        bool third_party_owner = variant->owner;
        long timeout_ns = variant->timeout_ns;
        bool broadcast = variant->broadcast;
        struct thread_arg args[THREAD_MAX];
        struct timespec ts, *tsp = NULL;
        bool lock = variant->locked;
        int *waiter_ret, i, ret = 0;

        ksft_print_msg(
                "\tArguments: broadcast=%d locked=%d owner=%d timeout=%ldns\n",
                broadcast, lock, third_party_owner, timeout_ns);

        if (timeout_ns) {
                time_t secs;

                ksft_print_dbg_msg("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;
                ksft_print_dbg_msg("ts.tv_sec  = %ld\n", ts.tv_sec);
                ksft_print_dbg_msg("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)) {
                        ksft_exit_fail_msg("Creating third party blocker thread failed\n");
                }
        }

        atomic_set(&waiters_woken, 0);
        for (i = 0; i < THREAD_MAX; i++) {
                args[i].id = i;
                args[i].timeout = tsp;
                ksft_print_dbg_msg("Starting thread %d\n", i);
                if (create_rt_thread(&waiter[i], waiterfn, (void *)&args[i],
                                     SCHED_FIFO, 1)) {
                        ksft_exit_fail_msg("Creating waiting thread failed\n");
                }
        }
        waker_arg.lock = lock;
        if (create_rt_thread(&waker, wakerfn, (void *)&waker_arg,
                             SCHED_FIFO, 1)) {
                ksft_exit_fail_msg("Creating waker thread failed\n");
        }

        /* 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);

        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;
        }

        if (ret)
                ksft_test_result_fail("fail");
}

TEST_HARNESS_MAIN