graphene/LibOS/shim/src/utils/strobjs.c

/* Copyright (C) 2014 Stony Brook University
   This file is part of Graphene Library OS.

   Graphene Library OS is free software: you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public License
   as published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   Graphene Library OS 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 Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/*
 * shim_syscalls.c
 *
 * This file contain functions to allocate / free a fixed-size string object.
 */

#include <shim_internal.h>
#include <shim_utils.h>

static struct shim_lock str_mgr_lock;

#define SYSTEM_LOCK()   lock(&str_mgr_lock)
#define SYSTEM_UNLOCK() unlock(&str_mgr_lock)

#define STR_MGR_ALLOC 32
#define PAGE_SIZE     allocsize

#define OBJ_TYPE struct shim_str
#include "memmgr.h"

static MEM_MGR str_mgr = NULL;

int init_str_mgr(void) {
    create_lock(&str_mgr_lock);
    str_mgr = create_mem_mgr(init_align_up(STR_MGR_ALLOC));
    return 0;
}

struct shim_str* get_str_obj(void) {
    return get_mem_obj_from_mgr_enlarge(str_mgr, size_align_up(STR_MGR_ALLOC));
}

int free_str_obj(struct shim_str* str) {
    if (str == NULL)
        return 0;

    if (memory_migrated(str)) {
        memset(str, 0, sizeof(struct shim_str));
        return 0;
    }

    free_mem_obj_to_mgr(str_mgr, str);
    return 0;
}