/*
 * Copyright (C) 2018 Oracle.
 * Copyright 2019 Joyent, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
 */

#include "smatch.h"
#include <fcntl.h>
#include <unistd.h>
#ifdef __sun
#include <sys/procfs.h>
#endif

static int my_id;

static unsigned long max_size;

#ifdef __sun
unsigned long get_mem_kb(void)
{
        static int my_fd = -2;
        prpsinfo_t pbuf;

        if (my_fd == -2) {
                /* Do not repeatedly attempt this if it fails. */
                my_fd = open("/proc/self/psinfo", O_RDONLY);
        }
        if (my_fd == -1) {
                return (0);
        }

        if (pread(my_fd, &pbuf, sizeof (pbuf), 0) != sizeof (pbuf)) {
                return (0);
        }

        return (pbuf.pr_rssize);
}
#else
unsigned long get_mem_kb(void)
{
        FILE *file;
        char buf[1024] = "0";
        unsigned long size;

        file = fopen("/proc/self/statm", "r");
        if (!file)
                return 0;
        fread(buf, 1, sizeof(buf), file);
        fclose(file);

        size = strtoul(buf, NULL, 10);
        size = size * sysconf(_SC_PAGESIZE) / 1024;
        return size;
}
#endif

static void match_end_func(struct symbol *sym)
{
        unsigned long size;

        if (option_mem) {
                size = get_mem_kb();
                if (size > max_size)
                        max_size = size;
        }
}

unsigned long get_max_memory(void)
{
        return max_size;
}

void register_mem_tracker(int id)
{
        my_id = id;

        add_hook(&match_end_func, END_FUNC_HOOK);
}