/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
 * Copyright (c) 2024 Emil Tsalapatis <etsal@meta.com>
 * Copyright (c) 2024 Tejun Heo <tj@kernel.org>
 * Copyright (c) 2022 David Vernet <dvernet@meta.com>
 */
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <libgen.h>
#include <bpf/bpf.h>
#include <scx/common.h>

#include "scx_sdt.h"
#include "scx_sdt.bpf.skel.h"

const char help_fmt[] =
"A simple arena-based sched_ext scheduler.\n"
"\n"
"Modified version of scx_simple that demonstrates arena-based data structures.\n"
"\n"
"Usage: %s [-f] [-v]\n"
"\n"
"  -v            Print libbpf debug messages\n"
"  -h            Display this help and exit\n";

static bool verbose;
static volatile int exit_req;

static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
{
        if (level == LIBBPF_DEBUG && !verbose)
                return 0;
        return vfprintf(stderr, format, args);
}

static void sigint_handler(int sig)
{
        exit_req = 1;
}

int main(int argc, char **argv)
{
        struct scx_sdt *skel;
        struct bpf_link *link;
        __u32 opt;
        __u64 ecode;

        libbpf_set_print(libbpf_print_fn);
        signal(SIGINT, sigint_handler);
        signal(SIGTERM, sigint_handler);
restart:
        optind = 1;
        skel = SCX_OPS_OPEN(sdt_ops, scx_sdt);

        while ((opt = getopt(argc, argv, "vh")) != -1) {
                switch (opt) {
                case 'v':
                        verbose = true;
                        break;
                default:
                        fprintf(stderr, help_fmt, basename(argv[0]));
                        return opt != 'h';
                }
        }

        SCX_OPS_LOAD(skel, sdt_ops, scx_sdt, uei);
        link = SCX_OPS_ATTACH(skel, sdt_ops, scx_sdt);

        while (!exit_req && !UEI_EXITED(skel, uei)) {
                printf("====SCHEDULING STATS====\n");
                printf("enqueues=%llu\t", skel->bss->stat_enqueue);
                printf("inits=%llu\t", skel->bss->stat_init);
                printf("exits=%llu\t", skel->bss->stat_exit);
                printf("\n");

                printf("select_idle_cpu=%llu\t", skel->bss->stat_select_idle_cpu);
                printf("select_busy_cpu=%llu\t", skel->bss->stat_select_busy_cpu);
                printf("\n");

                printf("====ALLOCATION STATS====\n");
                printf("chunk allocs=%llu\t", skel->bss->alloc_stats.chunk_allocs);
                printf("data_allocs=%llu\n", skel->bss->alloc_stats.data_allocs);
                printf("alloc_ops=%llu\t", skel->bss->alloc_stats.alloc_ops);
                printf("free_ops=%llu\t", skel->bss->alloc_stats.free_ops);
                printf("active_allocs=%llu\t", skel->bss->alloc_stats.active_allocs);
                printf("arena_pages_used=%llu\t", skel->bss->alloc_stats.arena_pages_used);
                printf("\n\n");

                fflush(stdout);
                sleep(1);
        }

        bpf_link__destroy(link);
        ecode = UEI_REPORT(skel, uei);
        scx_sdt__destroy(skel);

        if (UEI_ECODE_RESTART(ecode))
                goto restart;
        return 0;
}