// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
#include <stdlib.h>
#include <pthread.h>
#include <stdio.h>
#include <assert.h>

#include "regression.h"

static pthread_barrier_t worker_barrier;
static int obj0, obj1;
static RADIX_TREE(mt_tree, GFP_KERNEL);

static void *reader_fn(void *arg)
{
        int i;
        void *entry;

        rcu_register_thread();
        pthread_barrier_wait(&worker_barrier);

        for (i = 0; i < 1000000; i++) {
                rcu_read_lock();
                entry = radix_tree_lookup(&mt_tree, 0);
                rcu_read_unlock();
                if (entry != &obj0) {
                        printf("iteration %d bad entry = %p\n", i, entry);
                        abort();
                }
        }

        rcu_unregister_thread();

        return NULL;
}

static void *writer_fn(void *arg)
{
        int i;

        rcu_register_thread();
        pthread_barrier_wait(&worker_barrier);

        for (i = 0; i < 1000000; i++) {
                radix_tree_insert(&mt_tree, 1, &obj1);
                radix_tree_delete(&mt_tree, 1);
        }

        rcu_unregister_thread();

        return NULL;
}

void regression4_test(void)
{
        pthread_t reader, writer;

        printv(1, "regression test 4 starting\n");

        radix_tree_insert(&mt_tree, 0, &obj0);
        pthread_barrier_init(&worker_barrier, NULL, 2);

        if (pthread_create(&reader, NULL, reader_fn, NULL) ||
            pthread_create(&writer, NULL, writer_fn, NULL)) {
                perror("pthread_create");
                exit(1);
        }

        if (pthread_join(reader, NULL) || pthread_join(writer, NULL)) {
                perror("pthread_join");
                exit(1);
        }

        printv(1, "regression test 4 passed\n");
}