/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2018-2019 Arm Limited
 */

#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/queue.h>
#include <unistd.h>

#include <rte_atomic.h>
#include <rte_common.h>
#include <rte_cycles.h>
#include <rte_eal.h>
#include <rte_launch.h>
#include <rte_lcore.h>
#include <rte_memory.h>
#include <rte_per_lcore.h>
#include <rte_ticketlock.h>

#include "test.h"

/*
 * Ticketlock test
 * =============
 *
 * - There is a global ticketlock and a table of ticketlocks (one per lcore).
 *
 * - The test function takes all of these locks and launches the
 *   ``test_ticketlock_per_core()`` function on each core (except the main).
 *
 *   - The function takes the global lock, display something, then releases
 *     the global lock.
 *   - The function takes the per-lcore lock, display something, then releases
 *     the per-core lock.
 *
 * - The main function unlocks the per-lcore locks sequentially and
 *   waits between each lock. This triggers the display of a message
 *   for each core, in the correct order. The autotest script checks that
 *   this order is correct.
 *
 * - A load test is carried out, with all cores attempting to lock a single lock
 *   multiple times
 */

static rte_ticketlock_t tl, tl_try;
static rte_ticketlock_t tl_tab[RTE_MAX_LCORE];
static rte_ticketlock_recursive_t tlr;
static unsigned int count;

static rte_atomic32_t synchro;

static int
test_ticketlock_per_core(__rte_unused void *arg)
{
        rte_ticketlock_lock(&tl);
        printf("Global lock taken on core %u\n", rte_lcore_id());
        rte_ticketlock_unlock(&tl);

        rte_ticketlock_lock(&tl_tab[rte_lcore_id()]);
        printf("Hello from core %u !\n", rte_lcore_id());
        rte_ticketlock_unlock(&tl_tab[rte_lcore_id()]);

        return 0;
}

static int
test_ticketlock_recursive_per_core(__rte_unused void *arg)
{
        unsigned int id = rte_lcore_id();

        rte_ticketlock_recursive_lock(&tlr);
        printf("Global recursive lock taken on core %u - count = %d\n",
               id, tlr.count);
        rte_ticketlock_recursive_lock(&tlr);
        printf("Global recursive lock taken on core %u - count = %d\n",
               id, tlr.count);
        rte_ticketlock_recursive_lock(&tlr);
        printf("Global recursive lock taken on core %u - count = %d\n",
               id, tlr.count);

        printf("Hello from within recursive locks from core %u !\n", id);

        rte_ticketlock_recursive_unlock(&tlr);
        printf("Global recursive lock released on core %u - count = %d\n",
               id, tlr.count);
        rte_ticketlock_recursive_unlock(&tlr);
        printf("Global recursive lock released on core %u - count = %d\n",
               id, tlr.count);
        rte_ticketlock_recursive_unlock(&tlr);
        printf("Global recursive lock released on core %u - count = %d\n",
               id, tlr.count);

        return 0;
}

static rte_ticketlock_t lk = RTE_TICKETLOCK_INITIALIZER;
static uint64_t lcount __rte_cache_aligned;
static uint64_t lcore_count[RTE_MAX_LCORE] __rte_cache_aligned;
static uint64_t time_cost[RTE_MAX_LCORE];

#define MAX_LOOP 10000

static int
load_loop_fn(void *func_param)
{
        uint64_t time_diff = 0, begin;
        uint64_t hz = rte_get_timer_hz();
        const int use_lock = *(int *)func_param;
        const unsigned int lcore = rte_lcore_id();

        /* wait synchro for workers */
        if (lcore != rte_get_main_lcore())
                while (rte_atomic32_read(&synchro) == 0)
                        ;

        begin = rte_rdtsc_precise();
        while (lcore_count[lcore] < MAX_LOOP) {
                if (use_lock)
                        rte_ticketlock_lock(&lk);
                lcore_count[lcore]++;
                lcount++;
                if (use_lock)
                        rte_ticketlock_unlock(&lk);
        }
        time_diff = rte_rdtsc_precise() - begin;
        time_cost[lcore] = time_diff * 1000000 / hz;
        return 0;
}

static int
test_ticketlock_perf(void)
{
        unsigned int i;
        uint64_t tcount = 0;
        uint64_t total_time = 0;
        int lock = 0;
        const unsigned int lcore = rte_lcore_id();

        printf("\nTest with no lock on single core...\n");
        load_loop_fn(&lock);
        printf("Core [%u] cost time = %"PRIu64" us\n", lcore, time_cost[lcore]);
        memset(lcore_count, 0, sizeof(lcore_count));
        memset(time_cost, 0, sizeof(time_cost));

        printf("\nTest with lock on single core...\n");
        lock = 1;
        load_loop_fn(&lock);
        printf("Core [%u] cost time = %"PRIu64" us\n", lcore, time_cost[lcore]);
        memset(lcore_count, 0, sizeof(lcore_count));
        memset(time_cost, 0, sizeof(time_cost));

        lcount = 0;
        printf("\nTest with lock on %u cores...\n", rte_lcore_count());

        /* Clear synchro and start workers */
        rte_atomic32_set(&synchro, 0);
        rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MAIN);

        /* start synchro and launch test on main */
        rte_atomic32_set(&synchro, 1);
        load_loop_fn(&lock);

        rte_eal_mp_wait_lcore();

        RTE_LCORE_FOREACH(i) {
                printf("Core [%u] cost time = %"PRIu64" us\n", i, time_cost[i]);
                tcount += lcore_count[i];
                total_time += time_cost[i];
        }

        if (tcount != lcount)
                return -1;

        printf("Total cost time = %"PRIu64" us\n", total_time);

        return 0;
}

/*
 * Use rte_ticketlock_trylock() to trylock a ticketlock object,
 * If it could not lock the object successfully, it would
 * return immediately and the variable of "count" would be
 * increased by one per times. the value of "count" could be
 * checked as the result later.
 */
static int
test_ticketlock_try(__rte_unused void *arg)
{
        if (rte_ticketlock_trylock(&tl_try) == 0) {
                rte_ticketlock_lock(&tl);
                count++;
                rte_ticketlock_unlock(&tl);
        }

        return 0;
}


/*
 * Test rte_eal_get_lcore_state() in addition to ticketlocks
 * as we have "waiting" then "running" lcores.
 */
static int
test_ticketlock(void)
{
        int ret = 0;
        int i;

        /* worker cores should be waiting: print it */
        RTE_LCORE_FOREACH_WORKER(i) {
                printf("lcore %d state: %d\n", i,
                       (int) rte_eal_get_lcore_state(i));
        }

        rte_ticketlock_init(&tl);
        rte_ticketlock_init(&tl_try);
        rte_ticketlock_recursive_init(&tlr);
        RTE_LCORE_FOREACH_WORKER(i) {
                rte_ticketlock_init(&tl_tab[i]);
        }

        rte_ticketlock_lock(&tl);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_ticketlock_lock(&tl_tab[i]);
                rte_eal_remote_launch(test_ticketlock_per_core, NULL, i);
        }

        /* worker cores should be busy: print it */
        RTE_LCORE_FOREACH_WORKER(i) {
                printf("lcore %d state: %d\n", i,
                       (int) rte_eal_get_lcore_state(i));
        }
        rte_ticketlock_unlock(&tl);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_ticketlock_unlock(&tl_tab[i]);
                rte_delay_ms(10);
        }

        rte_eal_mp_wait_lcore();

        rte_ticketlock_recursive_lock(&tlr);

        /*
         * Try to acquire a lock that we already own
         */
        if (!rte_ticketlock_recursive_trylock(&tlr)) {
                printf("rte_ticketlock_recursive_trylock failed on a lock that "
                       "we already own\n");
                ret = -1;
        } else
                rte_ticketlock_recursive_unlock(&tlr);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_eal_remote_launch(test_ticketlock_recursive_per_core,
                                        NULL, i);
        }
        rte_ticketlock_recursive_unlock(&tlr);
        rte_eal_mp_wait_lcore();

        /*
         * Test if it could return immediately from try-locking a locked object.
         * Here it will lock the ticketlock object first, then launch all the
         * worker lcores to trylock the same ticketlock object.
         * All the worker lcores should give up try-locking a locked object and
         * return immediately, and then increase the "count" initialized with
         * zero by one per times.
         * We can check if the "count" is finally equal to the number of all
         * worker lcores to see if the behavior of try-locking a locked
         * ticketlock object is correct.
         */
        if (rte_ticketlock_trylock(&tl_try) == 0)
                return -1;

        count = 0;
        RTE_LCORE_FOREACH_WORKER(i) {
                rte_eal_remote_launch(test_ticketlock_try, NULL, i);
        }
        rte_eal_mp_wait_lcore();
        rte_ticketlock_unlock(&tl_try);
        if (rte_ticketlock_is_locked(&tl)) {
                printf("ticketlock is locked but it should not be\n");
                return -1;
        }
        rte_ticketlock_lock(&tl);
        if (count != (rte_lcore_count() - 1))
                ret = -1;

        rte_ticketlock_unlock(&tl);

        /*
         * Test if it can trylock recursively.
         * Use rte_ticketlock_recursive_trylock() to check if it can lock
         * a ticketlock object recursively. Here it will try to lock a
         * ticketlock object twice.
         */
        if (rte_ticketlock_recursive_trylock(&tlr) == 0) {
                printf("It failed to do the first ticketlock_recursive_trylock "
                           "but it should able to do\n");
                return -1;
        }
        if (rte_ticketlock_recursive_trylock(&tlr) == 0) {
                printf("It failed to do the second ticketlock_recursive_trylock "
                           "but it should able to do\n");
                return -1;
        }
        rte_ticketlock_recursive_unlock(&tlr);
        rte_ticketlock_recursive_unlock(&tlr);

        if (test_ticketlock_perf() < 0)
                return -1;

        return ret;
}

REGISTER_TEST_COMMAND(ticketlock_autotest, test_ticketlock);