root/ext/opcache/shared_alloc_mmap.c

DEFINITIONS

1. create_segments
2. detach_segment
3. segment_type_size

/*
   +----------------------------------------------------------------------+
   | Zend OPcache                                                         |
   +----------------------------------------------------------------------+
   | Copyright (c) 1998-2015 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@zend.com>                                |
   |          Zeev Suraski <zeev@zend.com>                                |
   |          Stanislav Malyshev <stas@zend.com>                          |
   |          Dmitry Stogov <dmitry@zend.com>                             |
   +----------------------------------------------------------------------+
*/

#include "zend_shared_alloc.h"

#ifdef USE_MMAP

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>

#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
# define MAP_ANONYMOUS MAP_ANON
#endif

static int create_segments(size_t requested_size, zend_shared_segment ***shared_segments_p, int *shared_segments_count, char **error_in)
{
        zend_shared_segment *shared_segment;

        *shared_segments_count = 1;
        *shared_segments_p = (zend_shared_segment **) calloc(1, sizeof(zend_shared_segment) + sizeof(void *));
        if (!*shared_segments_p) {
                *error_in = "calloc";
                return ALLOC_FAILURE;
        }
        shared_segment = (zend_shared_segment *)((char *)(*shared_segments_p) + sizeof(void *));
        (*shared_segments_p)[0] = shared_segment;

        shared_segment->p = mmap(0, requested_size, PROT_READ | PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
        if (shared_segment->p == MAP_FAILED) {
                *error_in = "mmap";
                return ALLOC_FAILURE;
        }

        shared_segment->pos = 0;
        shared_segment->size = requested_size;

        return ALLOC_SUCCESS;
}

static int detach_segment(zend_shared_segment *shared_segment)
{
        munmap(shared_segment->p, shared_segment->size);
        return 0;
}

static size_t segment_type_size(void)
{
        return sizeof(zend_shared_segment);
}

zend_shared_memory_handlers zend_alloc_mmap_handlers = {
        create_segments,
        detach_segment,
        segment_type_size
};

#endif /* USE_MMAP */