/*

   +----------------------------------------------------------------------+

   | Zend OPcache                                                         |

   +----------------------------------------------------------------------+

   | Copyright © The PHP Group and Contributors.                          |

   +----------------------------------------------------------------------+

   | This source file is subject to the Modified BSD License that is      |

   | bundled with this package in the file LICENSE, and is available      |

   | through the World Wide Web at <https://www.php.net/license/>.        |

   |                                                                      |

   | SPDX-License-Identifier: BSD-3-Clause                                |

   +----------------------------------------------------------------------+

   | Authors: Andi Gutmans <andi@php.net>                                 |

   |          Zeev Suraski <zeev@php.net>                                 |

   |          Stanislav Malyshev <stas@zend.com>                          |

   |          Dmitry Stogov <dmitry@php.net>                              |

   +----------------------------------------------------------------------+

*/

#include "zend_shared_alloc.h"

#ifdef USE_SHM_OPEN

#include <sys/types.h>

#include <sys/stat.h>

#include <stdio.h>

#include <fcntl.h>

#include <sys/mman.h>

#include <unistd.h>

#include <stdlib.h>

typedef struct  {

    zend_shared_segment common;

    int shm_fd;

} zend_shared_segment_posix;

static int create_segments(size_t requested_size, zend_shared_segment_posix ***shared_segments_p, int *shared_segments_count, const char **error_in)

{

  zend_shared_segment_posix *shared_segment;

  char shared_segment_name[sizeof("/ZendAccelerator.") + 20];

  int shared_segment_flags = O_RDWR|O_CREAT|O_TRUNC;

  mode_t shared_segment_mode = 0600;

#if defined(HAVE_SHM_CREATE_LARGEPAGE)

  /**

   * architectures have 3 entries max and we are interested

   * from the second offset minimum to be worthy creating

   * a special shared segment tagged as 'large'.

   * only then amd64/i386/arm64 and perharps risc64*

   * archs are on interest here.

   */

  size_t shared_segment_lg_index = 0;

  size_t shared_segment_sindexes[3] = {0};

  const size_t entries = sizeof(shared_segment_sindexes) / sizeof(shared_segment_sindexes[0]);

  int i, shared_segment_sizes;

  shared_segment_sizes = getpagesizes(shared_segment_sindexes, entries);

  if (shared_segment_sizes > 0) {

    for (i = shared_segment_sizes - 1; i >= 0; i --) {

      if (shared_segment_sindexes[i] != 0 &&

          !(requested_size % shared_segment_sindexes[i])) {

        shared_segment_lg_index = i;

        break;

      }

    }

  }

#endif

  *shared_segments_count = 1;

  *shared_segments_p = (zend_shared_segment_posix **) calloc(1, sizeof(zend_shared_segment_posix) + sizeof(void *));

  if (!*shared_segments_p) {

    *error_in = "calloc";

    return ALLOC_FAILURE;

  }

  shared_segment = (zend_shared_segment_posix *)((char *)(*shared_segments_p) + sizeof(void *));

  (*shared_segments_p)[0] = shared_segment;

  snprintf(shared_segment_name, sizeof(shared_segment_name), "/ZendAccelerator.%d", getpid());

#if defined(HAVE_SHM_CREATE_LARGEPAGE)

  if (shared_segment_lg_index > 0) {

    shared_segment->shm_fd =  shm_create_largepage(shared_segment_name, shared_segment_flags, shared_segment_lg_index, SHM_LARGEPAGE_ALLOC_DEFAULT, shared_segment_mode);

    if (shared_segment->shm_fd != -1) {

      goto truncate_segment;

    }

  }

#endif

  shared_segment->shm_fd = shm_open(shared_segment_name, shared_segment_flags, shared_segment_mode);

  if (shared_segment->shm_fd == -1) {

    *error_in = "shm_open";

    return ALLOC_FAILURE;

  }

#if defined(HAVE_SHM_CREATE_LARGEPAGE)

truncate_segment:

#endif

  if (ftruncate(shared_segment->shm_fd, requested_size) != 0) {

    *error_in = "ftruncate";

    shm_unlink(shared_segment_name);

    return ALLOC_FAILURE;

  }

  shared_segment->common.p = mmap(0, requested_size, PROT_READ | PROT_WRITE, MAP_SHARED, shared_segment->shm_fd, 0);

  if (shared_segment->common.p == MAP_FAILED) {

    *error_in = "mmap";

    shm_unlink(shared_segment_name);

    return ALLOC_FAILURE;

  }

  shm_unlink(shared_segment_name);

  shared_segment->common.pos = 0;

  shared_segment->common.size = requested_size;

  return ALLOC_SUCCESS;

}

static int detach_segment(zend_shared_segment_posix *shared_segment)

{

  munmap(shared_segment->common.p, shared_segment->common.size);

  close(shared_segment->shm_fd);

  return 0;

}

static size_t segment_type_size(void)

{

  return sizeof(zend_shared_segment_posix);

}

const zend_shared_memory_handlers zend_alloc_posix_handlers = {

  (create_segments_t)create_segments,

  (detach_segment_t)detach_segment,

  segment_type_size

};

#endif /* USE_SHM_OPEN */