/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2021 Microsoft Corporation
 */

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

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

#include "test.h"

/*
 * phase-fair lock test
 * ====================
 * Provides UT for phase-fair lock API.
 * Main concern is on functional testing, but also provides some
 * performance measurements.
 * Obviously for proper testing need to be executed with more than one lcore.
 */

static rte_pflock_t sl;
static rte_pflock_t sl_tab[RTE_MAX_LCORE];
static uint32_t synchro;

static int
test_pflock_per_core(__rte_unused void *arg)
{
        rte_pflock_write_lock(&sl);
        printf("Global write lock taken on core %u\n", rte_lcore_id());
        rte_pflock_write_unlock(&sl);

        rte_pflock_write_lock(&sl_tab[rte_lcore_id()]);
        printf("Hello from core %u !\n", rte_lcore_id());
        rte_pflock_write_unlock(&sl_tab[rte_lcore_id()]);

        rte_pflock_read_lock(&sl);
        printf("Global read lock taken on core %u\n", rte_lcore_id());
        rte_delay_ms(100);
        printf("Release global read lock on core %u\n", rte_lcore_id());
        rte_pflock_read_unlock(&sl);

        return 0;
}

static rte_pflock_t lk = RTE_PFLOCK_INITIALIZER;
static uint64_t time_count[RTE_MAX_LCORE] = {0};

#define MAX_LOOP 10000

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

        /* wait synchro for workers */
        if (lcore != rte_get_main_lcore())
                rte_wait_until_equal_32(&synchro, 1, __ATOMIC_RELAXED);

        begin = rte_rdtsc_precise();
        while (lcount < MAX_LOOP) {
                if (use_lock)
                        rte_pflock_write_lock(&lk);
                lcount++;
                if (use_lock)
                        rte_pflock_write_unlock(&lk);

                if (use_lock) {
                        rte_pflock_read_lock(&lk);
                        rte_pflock_read_unlock(&lk);
                }
        }

        time_diff = rte_rdtsc_precise() - begin;
        time_count[lcore] = time_diff * 1000000 / hz;
        return 0;
}

static int
test_pflock_perf(void)
{
        unsigned int i;
        int lock = 0;
        uint64_t total = 0;
        const unsigned int lcore = rte_lcore_id();

        printf("\nTest with no lock on single core...\n");
        __atomic_store_n(&synchro, 1, __ATOMIC_RELAXED);
        load_loop_fn(&lock);
        printf("Core [%u] Cost Time = %"PRIu64" us\n",
                        lcore, time_count[lcore]);
        memset(time_count, 0, sizeof(time_count));

        printf("\nTest with phase-fair lock on single core...\n");
        lock = 1;
        __atomic_store_n(&synchro, 1, __ATOMIC_RELAXED);
        load_loop_fn(&lock);
        printf("Core [%u] Cost Time = %"PRIu64" us\n",
                        lcore, time_count[lcore]);
        memset(time_count, 0, sizeof(time_count));

        printf("\nPhase-fair test on %u cores...\n", rte_lcore_count());

        /* clear synchro and start workers */
        __atomic_store_n(&synchro, 0, __ATOMIC_RELAXED);
        if (rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MAIN) < 0)
                return -1;

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

        rte_eal_mp_wait_lcore();

        RTE_LCORE_FOREACH(i) {
                printf("Core [%u] cost time = %"PRIu64" us\n",
                        i, time_count[i]);
                total += time_count[i];
        }

        printf("Total cost time = %"PRIu64" us\n", total);
        memset(time_count, 0, sizeof(time_count));

        return 0;
}

/*
 * - There is a global pflock and a table of pflocks (one per lcore).
 *
 * - The test function takes all of these locks and launches the
 *   ``test_pflock_per_core()`` function on each core (except the main).
 *
 *   - The function takes the global write lock, display something,
 *     then releases the global lock.
 *   - Then, it takes the per-lcore write lock, display something, and
 *     releases the per-core lock.
 *   - Finally, a read lock is taken during 100 ms, then released.
 *
 * - 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.
 *
 *   Then, it tries to take the global write lock and display the last
 *   message. The autotest script checks that the message order is correct.
 */
static int
test_pflock(void)
{
        int i;

        rte_pflock_init(&sl);
        for (i = 0; i < RTE_MAX_LCORE; i++)
                rte_pflock_init(&sl_tab[i]);

        rte_pflock_write_lock(&sl);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_pflock_write_lock(&sl_tab[i]);
                rte_eal_remote_launch(test_pflock_per_core, NULL, i);
        }

        rte_pflock_write_unlock(&sl);

        RTE_LCORE_FOREACH_WORKER(i) {
                rte_pflock_write_unlock(&sl_tab[i]);
                rte_delay_ms(100);
        }

        rte_pflock_write_lock(&sl);
        /* this message should be the last message of test */
        printf("Global write lock taken on main core %u\n", rte_lcore_id());
        rte_pflock_write_unlock(&sl);

        rte_eal_mp_wait_lcore();

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

        return 0;
}

REGISTER_TEST_COMMAND(pflock_autotest, test_pflock);