src/posix/picture.c

   1 /*****************************************************************************
   2  * picture.c:
   3  *****************************************************************************
   4  * Copyright (C) 2018 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <assert.h>
  26 #include <sys/types.h>
  27 #include <sys/mman.h>
  28
  29 #include <vlc_common.h>
  30 #include <vlc_fs.h>
  31 #include "misc/picture.h"
  32
  33 void *picture_Allocate(int *restrict fdp, size_t size)
  34 {
  35     int fd = vlc_memfd();
  36     if (fd == -1)
  37         return NULL;
  38
  39     if (ftruncate(fd, size)) {
  40 error:
  41         vlc_close(fd);
  42         return NULL;
  43     }
  44
  45     void *base = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  46     if (base == MAP_FAILED)
  47         goto error;
  48
  49     *fdp = fd;
  50     return base;
  51 }
  52
  53 void picture_Deallocate(int fd, void *base, size_t size)
  54 {
  55     munmap(base, size);
  56     vlc_close(fd);
  57 }