gtk2/gsk/gskalloc.c
Руслан Ижбулатов c02bc22cc5 Use aligned allocators for GtkSnapshot
Any data that is later fed to graphene must be
allocated with proper alignment, if graphene
uses SSE2 or GCC vector instructions.

This adds custom array code (a streamlined copy
of GArray with all unnecessary bells and whistles removed),
which is then used for the state_stack instead of GArray.

There's also a runtime check for the size of GtkSnapshotState
itself being a multiple of 16. If that is not so, any array
elements past the 0th element will lose alignment.
There are probably struct attributes that can
make GtkSnapshotState always have size that is a multiple
of 16, but we'll burn that bridge if we cross it.
2018-06-10 20:35:54 +00:00

131 lines
3.2 KiB
C

#include "config.h"
#if defined(HAVE_POSIX_MEMALIGN) && !defined(_XOPEN_SOURCE)
# define _XOPEN_SOURCE 600
#endif
#include "gskallocprivate.h"
#if defined(HAVE_MEMALIGN) || defined(HAVE__ALIGNED_MALLOC)
/* Required for _aligned_malloc() and _aligned_free() on Windows */
#include <malloc.h>
#endif
#include <errno.h>
#include <string.h>
#ifdef HAVE__ALIGNED_MALLOC
/* _aligned_malloc() takes parameters of aligned_alloc() in reverse order */
# define aligned_alloc(alignment, size) _aligned_malloc (size, alignment)
/* _aligned_malloc()'ed memory must be freed by _align_free() on Windows */
# define aligned_free(x) _aligned_free (x)
#else
# define aligned_free(x) free (x)
#endif
/*
* gsk_aligned_alloc:
* @size: the size of the memory to allocate
* @number: the multiples of @size to allocate
* @alignment: the alignment to be enforced, as a power of 2
*
* Allocates @number times @size memory, with the given @alignment.
*
* If the total requested memory overflows %G_MAXSIZE, this function
* will abort.
*
* If allocation fails, this function will abort, in line with
* the behaviour of GLib.
*
* Returns: (transfer full): the allocated memory
*/
gpointer
gsk_aligned_alloc (gsize size,
gsize number,
gsize alignment)
{
gpointer res = NULL;
gsize real_size;
if (G_UNLIKELY (number > G_MAXSIZE / size))
{
#ifndef G_DISABLE_ASSERT
g_error ("%s: overflow in the allocation of (%"G_GSIZE_FORMAT" x %"G_GSIZE_FORMAT") bytes",
G_STRLOC, size, number);
#endif
return NULL;
}
real_size = size * number;
#ifndef G_DISABLE_ASSERT
errno = 0;
#endif
#if defined(HAVE_POSIX_MEMALIGN) && !defined (MALLOC_IS_ALIGNED16)
errno = posix_memalign (&res, alignment, real_size);
#elif (defined(HAVE_ALIGNED_ALLOC) || defined(HAVE__ALIGNED_MALLOC)) && !defined (MALLOC_IS_ALIGNED16)
/* real_size must be a multiple of alignment */
if (real_size % alignment != 0)
{
gsize offset = real_size % alignment;
real_size += (alignment - offset);
}
res = aligned_alloc (alignment, real_size);
#elif defined(HAVE_MEMALIGN) && !defined (MALLOC_IS_ALIGNED16)
res = memalign (alignment, real_size);
#else
res = malloc (real_size);
#endif
#ifndef G_DISABLE_ASSERT
if (errno != 0 || res == NULL)
{
g_error ("%s: error in the allocation of (%"G_GSIZE_FORMAT" x %"G_GSIZE_FORMAT") bytes: %s",
G_STRLOC, size, number, strerror (errno));
}
#endif
return res;
}
/*
* gsk_aligned_alloc0:
* @size: the size of the memory to allocate
* @number: the multiples of @size to allocate
* @alignment: the alignment to be enforced, as a power of 2
*
* Allocates @number times @size memory, with the given @alignment,
* like gsk_aligned_alloc(), but it also clears the memory.
*
* Returns: (transfer full): the allocated, cleared memory
*/
gpointer
gsk_aligned_alloc0 (gsize size,
gsize number,
gsize alignment)
{
gpointer mem;
mem = gsk_aligned_alloc (size, number, alignment);
if (mem)
memset (mem, 0, size * number);
return mem;
}
/*
* gsk_aligned_free:
* @mem: the memory to deallocate
*
* Frees the memory allocated by gsk_aligned_alloc().
*/
void
gsk_aligned_free (gpointer mem)
{
aligned_free (mem);
}