elf/tst-tls21.c

   1 /* Test concurrent dlopen and pthread_create: BZ 19329.
   2    Copyright (C) 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <dlfcn.h>
  20 #include <pthread.h>
  21 #include <stdio.h>
  22 #include <stdatomic.h>
  23 #include <support/xdlfcn.h>
  24 #include <support/xthread.h>
  25
  26 #define THREADS 10000
  27
  28 static atomic_int done;
  29
  30 static void *
  31 start (void *a)
  32 {
  33   /* Load a module with many dependencies that each have TLS.  */
  34   xdlopen ("tst-tls21mod.so", RTLD_LAZY);
  35   atomic_store_explicit (&done, 1, memory_order_release);
  36   return 0;
  37 }
  38
  39 static void *
  40 nop (void *a)
  41 {
  42   return 0;
  43 }
  44
  45 static int
  46 do_test (void)
  47 {
  48   pthread_t t1, t2;
  49   int i;
  50
  51   /* Load a module with lots of dependencies and TLS.  */
  52   t1 = xpthread_create (0, start, 0);
  53
  54   /* Concurrently create lots of threads until dlopen is observably done.  */
  55   for (i = 0; i < THREADS; i++)
  56     {
  57       if (atomic_load_explicit (&done, memory_order_acquire) != 0)
  58         break;
  59       t2 = xpthread_create (0, nop, 0);
  60       xpthread_join (t2);
  61     }
  62
  63   xpthread_join (t1);
  64   printf ("threads created during dlopen: %d\n", i);
  65   return 0;
  66 }
  67
  68 #include <support/test-driver.c>