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/* slice-known-pages.c - test GSlice across known pages
* Copyright (C) 2007 Tim Janik
*
* This work is provided "as is"; redistribution and modification
* in whole or in part, in any medium, physical or electronic is
* permitted without restriction.
*
* This work is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* In no event shall the authors or contributors be liable for any
* direct, indirect, incidental, special, exemplary, or consequential
* damages (including, but not limited to, procurement of substitute
* goods or services; loss of use, data, or profits; or business
* interruption) however caused and on any theory of liability, whether
* in contract, strict liability, or tort (including negligence or
* otherwise) arising in any way out of the use of this software, even
* if advised of the possibility of such damage.
*/
#include <glib.h>
#define N_PAGES (101) /* number of pages to sample */
#define SAMPLE_SIZE (7)
#define PAGE_SIZE (128) /* must be <= minimum GSlice alignment block */
#define MAGAZINE_PROBES \
{ \
97, 265, 347 \
} /* block sizes hopefully unused */
#define MAX_PROBE_TRIALS (1031) /* must be >= maximum magazine size */
#define ALIGN(size, base) \
((base) * (gsize) (((size) + (base) - 1) / (base)))
static struct {
void *page;
void *sample;
} pages[N_PAGES] = { { NULL, NULL }, };
static const guint magazine_probes[] = MAGAZINE_PROBES;
#define N_MAGAZINE_PROBES G_N_ELEMENTS (magazine_probes)
static void
release_trash_list (GSList **trash_list,
gsize block_size)
{
while (*trash_list)
{
g_slice_free1 (block_size, (*trash_list)->data);
*trash_list = g_slist_delete_link (*trash_list, *trash_list);
}
}
static GSList *free_list = NULL;
static gboolean
allocate_from_known_page (void)
{
guint i, j, n_trials = N_PAGES * PAGE_SIZE / SAMPLE_SIZE; /* upper bound */
for (i = 0; i < n_trials; i++)
{
void *b = g_slice_alloc (SAMPLE_SIZE);
void *p = (void*) (PAGE_SIZE * ((gsize) b / PAGE_SIZE));
free_list = g_slist_prepend (free_list, b);
/* find page */
for (j = 0; j < N_PAGES; j++)
if (pages[j].page == p)
return TRUE;
}
return FALSE;
}
static void
test_slice_known_pages (void)
{
gsize j, n_pages = 0;
void *mps[N_MAGAZINE_PROBES];
/* probe some magazine sizes */
for (j = 0; j < N_MAGAZINE_PROBES; j++)
mps[j] = g_slice_alloc (magazine_probes[j]);
/* mps[*] now contains pointers to allocated slices */
/* allocate blocks from N_PAGES different pages */
while (n_pages < N_PAGES)
{
void *b = g_slice_alloc (SAMPLE_SIZE);
void *p = (void*) (PAGE_SIZE * ((gsize) b / PAGE_SIZE));
for (j = 0; j < N_PAGES; j++)
if (pages[j].page == p)
break;
if (j < N_PAGES) /* known page */
free_list = g_slist_prepend (free_list, b);
else /* new page */
{
j = n_pages++;
pages[j].page = p;
pages[j].sample = b;
}
}
/* release intermediate allocations */
release_trash_list (&free_list, SAMPLE_SIZE);
/* ensure that we can allocate from known pages */
g_assert_true (allocate_from_known_page());
/* release intermediate allocations */
release_trash_list (&free_list, SAMPLE_SIZE);
/* release magazine probes to be retained */
for (j = 0; j < N_MAGAZINE_PROBES; j++)
g_slice_free1 (magazine_probes[j], mps[j]);
/* mps[*] now contains pointers to released slices */
/* ensure probes were retained */
for (j = 0; j < N_MAGAZINE_PROBES; j++)
{
GSList *trash = NULL;
guint k;
for (k = 0; k < MAX_PROBE_TRIALS; k++)
{
void *mem = g_slice_alloc (magazine_probes[j]);
if (mem == mps[j])
break; /* reallocated previously freed slice */
trash = g_slist_prepend (trash, mem);
}
release_trash_list (&trash, magazine_probes[j]);
g_assert_cmpint (k, <, MAX_PROBE_TRIALS); /* failed to reallocate slice */
}
/* mps[*] now contains pointers to reallocated slices */
/* release magazine probes to be retained across known pages */
for (j = 0; j < N_MAGAZINE_PROBES; j++)
g_slice_free1 (magazine_probes[j], mps[j]);
/* mps[*] now contains pointers to released slices */
/* ensure probes were retained */
for (j = 0; j < N_MAGAZINE_PROBES; j++)
{
GSList *trash = NULL;
guint k;
for (k = 0; k < MAX_PROBE_TRIALS; k++)
{
void *mem = g_slice_alloc (magazine_probes[j]);
if (mem == mps[j])
break; /* reallocated previously freed slice */
trash = g_slist_prepend (trash, mem);
}
release_trash_list (&trash, magazine_probes[j]);
g_assert_cmpint (k, <, MAX_PROBE_TRIALS); /* failed to reallocate slice */
}
/* mps[*] now contains pointers to reallocated slices */
/* ensure that we can allocate from known pages */
g_assert_true (allocate_from_known_page());
/* some cleanups */
for (j = 0; j < N_MAGAZINE_PROBES; j++)
g_slice_free1 (magazine_probes[j], mps[j]);
release_trash_list (&free_list, SAMPLE_SIZE);
}
int
main (int argc, char *argv[])
{
g_test_init (&argc, &argv, NULL);
g_test_add_func ("/slice/known_pages", test_slice_known_pages);
return g_test_run ();
}
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