// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2023. Huawei Technologies Co., Ltd */
#include <argp.h>
#include <stdbool.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <fcntl.h>

#include "bench.h"
#include "bpf_util.h"
#include "cgroup_helpers.h"
#include "htab_mem_bench.skel.h"

struct htab_mem_use_case {
        const char *name;
        const char **progs;
        /* Do synchronization between addition thread and deletion thread */
        bool need_sync;
};

static struct htab_mem_ctx {
        const struct htab_mem_use_case *uc;
        struct htab_mem_bench *skel;
        pthread_barrier_t *notify;
        int fd;
} ctx;

const char *ow_progs[] = {"overwrite", NULL};
const char *batch_progs[] = {"batch_add_batch_del", NULL};
const char *add_del_progs[] = {"add_only", "del_only", NULL};
const static struct htab_mem_use_case use_cases[] = {
        { .name = "overwrite", .progs = ow_progs },
        { .name = "batch_add_batch_del", .progs = batch_progs },
        { .name = "add_del_on_diff_cpu", .progs = add_del_progs, .need_sync = true },
};

static struct htab_mem_args {
        u32 value_size;
        const char *use_case;
        bool preallocated;
} args = {
        .value_size = 8,
        .use_case = "overwrite",
        .preallocated = false,
};

enum {
        ARG_VALUE_SIZE = 10000,
        ARG_USE_CASE = 10001,
        ARG_PREALLOCATED = 10002,
};

static const struct argp_option opts[] = {
        { "value-size", ARG_VALUE_SIZE, "VALUE_SIZE", 0,
          "Set the value size of hash map (default 8)" },
        { "use-case", ARG_USE_CASE, "USE_CASE", 0,
          "Set the use case of hash map: overwrite|batch_add_batch_del|add_del_on_diff_cpu" },
        { "preallocated", ARG_PREALLOCATED, NULL, 0, "use preallocated hash map" },
        {},
};

static error_t htab_mem_parse_arg(int key, char *arg, struct argp_state *state)
{
        switch (key) {
        case ARG_VALUE_SIZE:
                args.value_size = strtoul(arg, NULL, 10);
                if (args.value_size > 4096) {
                        fprintf(stderr, "too big value size %u\n", args.value_size);
                        argp_usage(state);
                }
                break;
        case ARG_USE_CASE:
                args.use_case = strdup(arg);
                if (!args.use_case) {
                        fprintf(stderr, "no mem for use-case\n");
                        argp_usage(state);
                }
                break;
        case ARG_PREALLOCATED:
                args.preallocated = true;
                break;
        default:
                return ARGP_ERR_UNKNOWN;
        }

        return 0;
}

const struct argp bench_htab_mem_argp = {
        .options = opts,
        .parser = htab_mem_parse_arg,
};

static void htab_mem_validate(void)
{
        if (!strcmp(use_cases[2].name, args.use_case) && env.producer_cnt % 2) {
                fprintf(stderr, "%s needs an even number of producers\n", args.use_case);
                exit(1);
        }
}

static int htab_mem_bench_init_barriers(void)
{
        pthread_barrier_t *barriers;
        unsigned int i, nr;

        if (!ctx.uc->need_sync)
                return 0;

        nr = (env.producer_cnt + 1) / 2;
        barriers = calloc(nr, sizeof(*barriers));
        if (!barriers)
                return -1;

        /* Used for synchronization between two threads */
        for (i = 0; i < nr; i++)
                pthread_barrier_init(&barriers[i], NULL, 2);

        ctx.notify = barriers;
        return 0;
}

static void htab_mem_bench_exit_barriers(void)
{
        unsigned int i, nr;

        if (!ctx.notify)
                return;

        nr = (env.producer_cnt + 1) / 2;
        for (i = 0; i < nr; i++)
                pthread_barrier_destroy(&ctx.notify[i]);
        free(ctx.notify);
}

static const struct htab_mem_use_case *htab_mem_find_use_case_or_exit(const char *name)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(use_cases); i++) {
                if (!strcmp(name, use_cases[i].name))
                        return &use_cases[i];
        }

        fprintf(stderr, "no such use-case: %s\n", name);
        fprintf(stderr, "available use case:");
        for (i = 0; i < ARRAY_SIZE(use_cases); i++)
                fprintf(stderr, " %s", use_cases[i].name);
        fprintf(stderr, "\n");
        exit(1);
}

static void htab_mem_setup(void)
{
        struct bpf_map *map;
        const char **names;
        int err;

        setup_libbpf();

        ctx.uc = htab_mem_find_use_case_or_exit(args.use_case);
        err = htab_mem_bench_init_barriers();
        if (err) {
                fprintf(stderr, "failed to init barrier\n");
                exit(1);
        }

        ctx.fd = cgroup_setup_and_join("/htab_mem");
        if (ctx.fd < 0)
                goto cleanup;

        ctx.skel = htab_mem_bench__open();
        if (!ctx.skel) {
                fprintf(stderr, "failed to open skeleton\n");
                goto cleanup;
        }

        map = ctx.skel->maps.htab;
        bpf_map__set_value_size(map, args.value_size);
        /* Ensure that different CPUs can operate on different subset */
        bpf_map__set_max_entries(map, MAX(8192, 64 * env.nr_cpus));
        if (args.preallocated)
                bpf_map__set_map_flags(map, bpf_map__map_flags(map) & ~BPF_F_NO_PREALLOC);

        names = ctx.uc->progs;
        while (*names) {
                struct bpf_program *prog;

                prog = bpf_object__find_program_by_name(ctx.skel->obj, *names);
                if (!prog) {
                        fprintf(stderr, "no such program %s\n", *names);
                        goto cleanup;
                }
                bpf_program__set_autoload(prog, true);
                names++;
        }
        ctx.skel->bss->nr_thread = env.producer_cnt;

        err = htab_mem_bench__load(ctx.skel);
        if (err) {
                fprintf(stderr, "failed to load skeleton\n");
                goto cleanup;
        }
        err = htab_mem_bench__attach(ctx.skel);
        if (err) {
                fprintf(stderr, "failed to attach skeleton\n");
                goto cleanup;
        }
        return;

cleanup:
        htab_mem_bench__destroy(ctx.skel);
        htab_mem_bench_exit_barriers();
        if (ctx.fd >= 0) {
                close(ctx.fd);
                cleanup_cgroup_environment();
        }
        exit(1);
}

static void htab_mem_add_fn(pthread_barrier_t *notify)
{
        while (true) {
                /* Do addition */
                (void)syscall(__NR_getpgid, 0);
                /* Notify deletion thread to do deletion */
                pthread_barrier_wait(notify);
                /* Wait for deletion to complete */
                pthread_barrier_wait(notify);
        }
}

static void htab_mem_delete_fn(pthread_barrier_t *notify)
{
        while (true) {
                /* Wait for addition to complete */
                pthread_barrier_wait(notify);
                /* Do deletion */
                (void)syscall(__NR_getppid);
                /* Notify addition thread to do addition */
                pthread_barrier_wait(notify);
        }
}

static void *htab_mem_producer(void *arg)
{
        pthread_barrier_t *notify;
        int seq;

        if (!ctx.uc->need_sync) {
                while (true)
                        (void)syscall(__NR_getpgid, 0);
                return NULL;
        }

        seq = (long)arg;
        notify = &ctx.notify[seq / 2];
        if (seq & 1)
                htab_mem_delete_fn(notify);
        else
                htab_mem_add_fn(notify);
        return NULL;
}

static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value)
{
        char buf[32];
        ssize_t got;
        int fd;

        fd = openat(ctx.fd, name, O_RDONLY);
        if (fd < 0) {
                /* cgroup v1 ? */
                fprintf(stderr, "no %s\n", name);
                *value = 0;
                return;
        }

        got = read(fd, buf, sizeof(buf) - 1);
        close(fd);
        if (got <= 0) {
                *value = 0;
                return;
        }
        buf[got] = 0;

        *value = strtoull(buf, NULL, 0);
}

static void htab_mem_measure(struct bench_res *res)
{
        res->hits = atomic_swap(&ctx.skel->bss->op_cnt, 0) / env.producer_cnt;
        htab_mem_read_mem_cgrp_file("memory.current", &res->gp_ct);
}

static void htab_mem_report_progress(int iter, struct bench_res *res, long delta_ns)
{
        double loop, mem;

        loop = res->hits / 1000.0 / (delta_ns / 1000000000.0);
        mem = res->gp_ct / 1048576.0;
        printf("Iter %3d (%7.3lfus): ", iter, (delta_ns - 1000000000) / 1000.0);
        printf("per-prod-op %7.2lfk/s, memory usage %7.2lfMiB\n", loop, mem);
}

static void htab_mem_report_final(struct bench_res res[], int res_cnt)
{
        double mem_mean = 0.0, mem_stddev = 0.0;
        double loop_mean = 0.0, loop_stddev = 0.0;
        unsigned long peak_mem;
        int i;

        for (i = 0; i < res_cnt; i++) {
                loop_mean += res[i].hits / 1000.0 / (0.0 + res_cnt);
                mem_mean += res[i].gp_ct / 1048576.0 / (0.0 + res_cnt);
        }
        if (res_cnt > 1)  {
                for (i = 0; i < res_cnt; i++) {
                        loop_stddev += (loop_mean - res[i].hits / 1000.0) *
                                       (loop_mean - res[i].hits / 1000.0) /
                                       (res_cnt - 1.0);
                        mem_stddev += (mem_mean - res[i].gp_ct / 1048576.0) *
                                      (mem_mean - res[i].gp_ct / 1048576.0) /
                                      (res_cnt - 1.0);
                }
                loop_stddev = sqrt(loop_stddev);
                mem_stddev = sqrt(mem_stddev);
        }

        htab_mem_read_mem_cgrp_file("memory.peak", &peak_mem);
        printf("Summary: per-prod-op %7.2lf \u00B1 %7.2lfk/s, memory usage %7.2lf \u00B1 %7.2lfMiB,"
               " peak memory usage %7.2lfMiB\n",
               loop_mean, loop_stddev, mem_mean, mem_stddev, peak_mem / 1048576.0);

        close(ctx.fd);
        cleanup_cgroup_environment();
}

const struct bench bench_htab_mem = {
        .name = "htab-mem",
        .argp = &bench_htab_mem_argp,
        .validate = htab_mem_validate,
        .setup = htab_mem_setup,
        .producer_thread = htab_mem_producer,
        .measure = htab_mem_measure,
        .report_progress = htab_mem_report_progress,
        .report_final = htab_mem_report_final,
};