/* SPDX-License-Identifier: GPL-2.0 */
/*
 * A scheduler that verifies that we do proper counting of init, enable, etc
 * callbacks.
 *
 * 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 <scx/common.bpf.h>

char _license[] SEC("license") = "GPL";

u64 init_task_cnt, exit_task_cnt, enable_cnt, disable_cnt;
u64 init_fork_cnt, init_transition_cnt;

s32 BPF_STRUCT_OPS_SLEEPABLE(cnt_init_task, struct task_struct *p,
                             struct scx_init_task_args *args)
{
        __sync_fetch_and_add(&init_task_cnt, 1);

        if (args->fork)
                __sync_fetch_and_add(&init_fork_cnt, 1);
        else
                __sync_fetch_and_add(&init_transition_cnt, 1);

        return 0;
}

void BPF_STRUCT_OPS(cnt_exit_task, struct task_struct *p)
{
        __sync_fetch_and_add(&exit_task_cnt, 1);
}

void BPF_STRUCT_OPS(cnt_enable, struct task_struct *p)
{
        __sync_fetch_and_add(&enable_cnt, 1);
}

void BPF_STRUCT_OPS(cnt_disable, struct task_struct *p)
{
        __sync_fetch_and_add(&disable_cnt, 1);
}

SEC(".struct_ops.link")
struct sched_ext_ops init_enable_count_ops = {
        .init_task      = (void *) cnt_init_task,
        .exit_task      = (void *) cnt_exit_task,
        .enable         = (void *) cnt_enable,
        .disable        = (void *) cnt_disable,
        .name           = "init_enable_count",
};