/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
 * Copyright (c) 2023 David Vernet <dvernet@meta.com>
 * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
 */
#include <bpf/bpf.h>
#include <scx/common.h>
#include <sys/wait.h>
#include <unistd.h>
#include "select_cpu_dfl_nodispatch.bpf.skel.h"
#include "scx_test.h"

#define NUM_CHILDREN 1028

static enum scx_test_status setup(void **ctx)
{
        struct select_cpu_dfl_nodispatch *skel;

        skel = select_cpu_dfl_nodispatch__open();
        SCX_FAIL_IF(!skel, "Failed to open");
        SCX_ENUM_INIT(skel);
        SCX_FAIL_IF(select_cpu_dfl_nodispatch__load(skel), "Failed to load skel");

        *ctx = skel;

        return SCX_TEST_PASS;
}

static enum scx_test_status run(void *ctx)
{
        struct select_cpu_dfl_nodispatch *skel = ctx;
        struct bpf_link *link;
        pid_t pids[NUM_CHILDREN];
        int i, status;

        link = bpf_map__attach_struct_ops(skel->maps.select_cpu_dfl_nodispatch_ops);
        SCX_FAIL_IF(!link, "Failed to attach scheduler");

        for (i = 0; i < NUM_CHILDREN; i++) {
                pids[i] = fork();
                if (pids[i] == 0) {
                        sleep(1);
                        exit(0);
                }
        }

        for (i = 0; i < NUM_CHILDREN; i++) {
                SCX_EQ(waitpid(pids[i], &status, 0), pids[i]);
                SCX_EQ(status, 0);
        }

        SCX_ASSERT(skel->bss->saw_local);

        bpf_link__destroy(link);

        return SCX_TEST_PASS;
}

static void cleanup(void *ctx)
{
        struct select_cpu_dfl_nodispatch *skel = ctx;

        select_cpu_dfl_nodispatch__destroy(skel);
}

struct scx_test select_cpu_dfl_nodispatch = {
        .name = "select_cpu_dfl_nodispatch",
        .description = "Verify behavior of scx_bpf_select_cpu_dfl() in "
                       "ops.select_cpu()",
        .setup = setup,
        .run = run,
        .cleanup = cleanup,
};
REGISTER_SCX_TEST(&select_cpu_dfl_nodispatch)