#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "pagealign_alloc.h"
#include <errno.h>
#include <stdlib.h>
#include <fcntl.h>
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#if HAVE_MMAP
# include <sys/mman.h>
#endif
#include "error.h"
#include "exit.h"
#include "getpagesize.h"
#include "xalloc.h"
#include "gettext.h"
#define _(str) gettext (str)
#if HAVE_MMAP
# ifndef MAP_FILE
# define MAP_FILE 0
# endif
# ifndef MAP_FAILED
# define MAP_FAILED ((void *)-1)
# endif
#endif
#if HAVE_MMAP || ! HAVE_POSIX_MEMALIGN
# if HAVE_MMAP
typedef size_t info_t;
# else
typedef void * info_t;
# endif
typedef struct memnode_s memnode_t;
struct memnode_s
{
void *aligned_ptr;
info_t info;
memnode_t *next;
};
static memnode_t *memnode_table = NULL;
static void
new_memnode (void *aligned_ptr, info_t info)
{
memnode_t *new_node = (memnode_t *) xmalloc (sizeof (memnode_t));
new_node->aligned_ptr = aligned_ptr;
new_node->info = info;
new_node->next = memnode_table;
memnode_table = new_node;
}
static info_t
get_memnode (void *aligned_ptr)
{
info_t ret;
memnode_t *c;
memnode_t **p_next = &memnode_table;
for (c = *p_next; c != NULL; p_next = &c->next, c = c->next)
if (c->aligned_ptr == aligned_ptr)
break;
if (c == NULL)
abort ();
*p_next = c->next;
ret = c->info;
free (c);
return ret;
}
#endif
void *
pagealign_alloc (size_t size)
{
void *ret;
#if HAVE_MMAP
# ifdef HAVE_MAP_ANONYMOUS
const int fd = -1;
const int flags = MAP_ANONYMOUS | MAP_PRIVATE;
# else
static int fd = -1;
const int flags = MAP_FILE | MAP_PRIVATE;
if (fd == -1)
{
fd = open ("/dev/zero", O_RDONLY, 0666);
if (fd < 0)
error (EXIT_FAILURE, errno, _("Failed to open /dev/zero for read"));
}
# endif
ret = mmap (NULL, size, PROT_READ | PROT_WRITE, flags, fd, 0);
if (ret == MAP_FAILED)
return NULL;
new_memnode (ret, size);
#elif HAVE_POSIX_MEMALIGN
int status = posix_memalign (&ret, getpagesize (), size);
if (status)
{
errno = status;
return NULL;
}
#else
size_t pagesize = getpagesize ();
void *unaligned_ptr = malloc (size + pagesize - 1);
if (unaligned_ptr == NULL)
{
errno = ENOMEM;
return NULL;
}
ret = (char *) unaligned_ptr
+ ((- (unsigned long) unaligned_ptr) & (pagesize - 1));
new_memnode (ret, unaligned_ptr);
#endif
return ret;
}
void *
pagealign_xalloc (size_t size)
{
void *ret;
ret = pagealign_alloc (size);
if (ret == NULL)
xalloc_die ();
return ret;
}
void
pagealign_free (void *aligned_ptr)
{
#if HAVE_MMAP
if (munmap (aligned_ptr, get_memnode (aligned_ptr)) < 0)
error (EXIT_FAILURE, errno, "Failed to unmap memory");
#elif HAVE_POSIX_MEMALIGN
free (aligned_ptr);
#else
free (get_memnode (aligned_ptr));
#endif
}