1 /* Smoke test for malloc_info.
2    Copyright (C) 2017-2022 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 /* The purpose of this test is to provide a quick way to run
20    malloc_info in a multi-threaded process.  */
21 
22 #include <array_length.h>
23 #include <malloc.h>
24 #include <stdlib.h>
25 #include <support/support.h>
26 #include <support/xthread.h>
27 
28 /* This barrier is used to have the main thread wait until the helper
29    threads have performed their allocations.  */
30 static pthread_barrier_t barrier;
31 
32 enum
33   {
34     /* Number of threads performing allocations.  */
35     thread_count  = 4,
36 
37     /* Amount of memory allocation per thread.  This should be large
38        enough to cause the allocation of multiple heaps per arena.  */
39     per_thread_allocations
40       = sizeof (void *) == 4 ? 16 * 1024 * 1024 : 128 * 1024 * 1024,
41   };
42 
43 static void *
allocation_thread_function(void * closure)44 allocation_thread_function (void *closure)
45 {
46   struct list
47   {
48     struct list *next;
49     long dummy[4];
50   };
51 
52   struct list *head = NULL;
53   size_t allocated = 0;
54   while (allocated < per_thread_allocations)
55     {
56       struct list *new_head = xmalloc (sizeof (*new_head));
57       allocated += sizeof (*new_head);
58       new_head->next = head;
59       head = new_head;
60     }
61 
62   xpthread_barrier_wait (&barrier);
63 
64   /* Main thread prints first statistics here.  */
65 
66   xpthread_barrier_wait (&barrier);
67 
68   while (head != NULL)
69     {
70       struct list *next_head = head->next;
71       free (head);
72       head = next_head;
73     }
74 
75   return NULL;
76 }
77 
78 static int
do_test(void)79 do_test (void)
80 {
81   xpthread_barrier_init (&barrier, NULL, thread_count + 1);
82 
83   pthread_t threads[thread_count];
84   for (size_t i = 0; i < array_length (threads); ++i)
85     threads[i] = xpthread_create (NULL, allocation_thread_function, NULL);
86 
87   xpthread_barrier_wait (&barrier);
88   puts ("info: After allocation:");
89   malloc_info (0, stdout);
90 
91   xpthread_barrier_wait (&barrier);
92   for (size_t i = 0; i < array_length (threads); ++i)
93     xpthread_join (threads[i]);
94 
95   puts ("\ninfo: After deallocation:");
96   malloc_info (0, stdout);
97 
98   return 0;
99 }
100 
101 #include <support/test-driver.c>
102