malloc/tst-malloc-thread-exit.c

   1 /* Test malloc with concurrent thread termination.
   2    Copyright (C) 2015-2023 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 thread spawns a number of outer threads, equal to the arena
  20    limit.  The outer threads run a loop which start and join two
  21    different kinds of threads: the first kind allocates (attaching an
  22    arena to the thread; malloc_first_thread) and waits, the second
  23    kind waits and allocates (wait_first_threads).  Both kinds of
  24    threads exit immediately after waiting.  The hope is that this will
  25    exhibit races in thread termination and arena management,
  26    particularly related to the arena free list.  */
  27
  28 #include <errno.h>
  29 #include <malloc.h>
  30 #include <pthread.h>
  31 #include <stdbool.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <unistd.h>
  35
  36 #include <support/support.h>
  37 #include <support/xthread.h>
  38 #include <support/test-driver.h>
  39
  40 static bool termination_requested;
  41 static int inner_thread_count = 4;
  42 static size_t malloc_size = 32;
  43
  44 static void
  45 __attribute__ ((noinline, noclone))
  46 unoptimized_free (void *ptr)
  47 {
  48   free (ptr);
  49 }
  50
  51 static void *
  52 malloc_first_thread (void * closure)
  53 {
  54   pthread_barrier_t *barrier = closure;
  55   void *ptr = xmalloc (malloc_size);
  56   xpthread_barrier_wait (barrier);
  57   unoptimized_free (ptr);
  58   return NULL;
  59 }
  60
  61 static void *
  62 wait_first_thread (void * closure)
  63 {
  64   pthread_barrier_t *barrier = closure;
  65   xpthread_barrier_wait (barrier);
  66   void *ptr = xmalloc (malloc_size);
  67   unoptimized_free (ptr);
  68   return NULL;
  69 }
  70
  71 static void *
  72 outer_thread (void *closure)
  73 {
  74   pthread_t *threads = xcalloc (sizeof (*threads), inner_thread_count);
  75   while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
  76     {
  77       pthread_barrier_t barrier;
  78       xpthread_barrier_init (&barrier, NULL, inner_thread_count + 1);
  79       for (int i = 0; i < inner_thread_count; ++i)
  80         {
  81           void *(*func) (void *);
  82           if ((i  % 2) == 0)
  83             func = malloc_first_thread;
  84           else
  85             func = wait_first_thread;
  86           threads[i] = xpthread_create (NULL, func, &barrier);
  87         }
  88       xpthread_barrier_wait (&barrier);
  89       for (int i = 0; i < inner_thread_count; ++i)
  90         xpthread_join (threads[i]);
  91       xpthread_barrier_destroy (&barrier);
  92     }
  93
  94   free (threads);
  95
  96   return NULL;
  97 }
  98
  99 static int
 100 do_test (void)
 101 {
 102   /* The number of threads should be smaller than the number of
 103      arenas, so that there will be some free arenas to add to the
 104      arena free list.  */
 105   enum { outer_thread_count = 2 };
 106   if (mallopt (M_ARENA_MAX, 8) == 0)
 107     {
 108       printf ("error: mallopt (M_ARENA_MAX) failed\n");
 109       return 1;
 110     }
 111
 112   /* Leave some room for shutting down all threads gracefully.  */
 113   int timeout = 3;
 114   if (timeout > DEFAULT_TIMEOUT)
 115     timeout = DEFAULT_TIMEOUT - 1;
 116
 117   pthread_t *threads = xcalloc (sizeof (*threads), outer_thread_count);
 118   for (long i = 0; i < outer_thread_count; ++i)
 119     threads[i] = xpthread_create (NULL, outer_thread, NULL);
 120
 121   struct timespec ts = {timeout, 0};
 122   if (nanosleep (&ts, NULL))
 123     {
 124       printf ("error: error: nanosleep: %m\n");
 125       abort ();
 126     }
 127
 128   __atomic_store_n (&termination_requested, true, __ATOMIC_RELAXED);
 129
 130   for (long i = 0; i < outer_thread_count; ++i)
 131     xpthread_join (threads[i]);
 132   free (threads);
 133
 134   return 0;
 135 }
 136
 137 #include <support/test-driver.c>