1 /* Test that glibc.malloc.mxfast tunable works.
2    Copyright (C) 2019-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 /* This test verifies that setting the glibc.malloc.mxfast tunable to
20    zero results in free'd blocks being returned to the small bins, not
21    the fast bins.  */
22 
23 #include <malloc.h>
24 #include <libc-diag.h>
25 #include <support/check.h>
26 
27 int
do_test(void)28 do_test (void)
29 {
30   struct mallinfo m;
31   char *volatile p1;
32   char *volatile p2;
33 
34   /* Arbitrary value; must be in default fastbin range.  */
35   p1 = malloc (3);
36   /* Something large so that p1 isn't a "top block" */
37   p2 = malloc (512);
38   free (p1);
39 
40   /* The test below covers the deprecated mallinfo function.  */
41   DIAG_PUSH_NEEDS_COMMENT;
42   DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
43 
44   m = mallinfo ();
45 
46   DIAG_POP_NEEDS_COMMENT;
47 
48   /* This will fail if there are any blocks in the fastbins.  */
49   TEST_COMPARE (m.smblks, 0);
50 
51   /* To keep gcc happy.  */
52   free (p2);
53 
54   return 0;
55 }
56 
57 #include <support/test-driver.c>
58