malloc/tst-malloc_info.c

   1 /* Smoke test for malloc_info.
   2    Copyright (C) 2017-2021 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 *
  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
  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>