1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
/* Test pagealign_alloc module.
Copyright (C) 2025-2026 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2025. */
#include <config.h>
/* Specification. */
#include "pagealign_alloc.h"
/* This test verifies that allocating and then freeing N pages is O(N),
not O(N²). */
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include "xalloc.h"
int
main (int argc, char *argv[])
{
#if HAVE_DECL_ALARM
/* Declare failure if test takes too long, by using default abort
caused by SIGALRM.
On a fast x86_64 machine in 2025, with the PA_IMPL_MALLOC implementation,
the execution times are:
n | time | time |
| linear list | hash set |
-------+-------------+----------+
10000 | 0.15 sec | 0.03 sec |
25000 | 0.8 sec | 0.07 sec |
50000 | 3.1 sec | 0.13 sec |
100000 | 14 sec | 0.26 sec |
*/
int alarm_value = 10;
signal (SIGALRM, SIG_DFL);
alarm (alarm_value);
#endif
int n;
if (argc > 1)
n = atoi (argv[1]);
else
{
#if defined __CYGWIN__
n = 25000;
#else
n = (sizeof (void *) <= 4 ? 25000 : 50000);
#endif
}
void **pages = XNMALLOC (n, void *);
size_t pagesize = getpagesize ();
for (int i = 0; i < n; i++)
pages[i] = pagealign_xalloc (pagesize);
/* Free half of the pages in allocation order and the other half of the pages
in reverse allocation order. */
int half = n / 2;
for (int i = 0; i < half; i++)
pagealign_free (pages[i]);
for (int i = n - 1; i >= half; i--)
pagealign_free (pages[i]);
return 0;
}
|
