tests/test-tls.c

   1 /* Test of thread-local storage in multithreaded situations.
   2    Copyright (C) 2005, 2008-2019 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible <bruno@clisp.org>, 2005.  */
  18
  19 #include <config.h>
  20
  21 #if USE_POSIX_THREADS || USE_SOLARIS_THREADS || USE_PTH_THREADS || USE_WINDOWS_THREADS
  22
  23 #if USE_POSIX_THREADS
  24 # define TEST_POSIX_THREADS 1
  25 #endif
  26 #if USE_SOLARIS_THREADS
  27 # define TEST_SOLARIS_THREADS 1
  28 #endif
  29 #if USE_PTH_THREADS
  30 # define TEST_PTH_THREADS 1
  31 #endif
  32 #if USE_WINDOWS_THREADS
  33 # define TEST_WINDOWS_THREADS 1
  34 #endif
  35
  36 /* Whether to help the scheduler through explicit yield().
  37    Uncomment this to see if the operating system has a fair scheduler.  */
  38 #define EXPLICIT_YIELD 1
  39
  40 /* Whether to print debugging messages.  */
  41 #define ENABLE_DEBUGGING 0
  42
  43 /* Number of simultaneous threads.  */
  44 #define THREAD_COUNT 16
  45
  46 /* Number of operations performed in each thread.  */
  47 #define REPEAT_COUNT 50000
  48
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52
  53 #include "glthread/tls.h"
  54 #include "glthread/thread.h"
  55 #include "glthread/yield.h"
  56
  57 #if ENABLE_DEBUGGING
  58 # define dbgprintf printf
  59 #else
  60 # define dbgprintf if (0) printf
  61 #endif
  62
  63 #if EXPLICIT_YIELD
  64 # define yield() gl_thread_yield ()
  65 #else
  66 # define yield()
  67 #endif
  68
  69 static void
  70 perhaps_yield (void)
  71 {
  72   /* Call yield () only with a certain probability, otherwise with GNU Pth
  73      the sequence of thread activations is too predictable.  */
  74   if ((((unsigned int) rand () >> 3) % 4) == 0)
  75     yield ();
  76 }
  77
  78
  79 /* ----------------------- Test thread-local storage ----------------------- */
  80
  81 #define KEYS_COUNT 4
  82
  83 static gl_tls_key_t mykeys[KEYS_COUNT];
  84
  85 static void *
  86 worker_thread (void *arg)
  87 {
  88   unsigned int id = (unsigned int) (unsigned long) arg;
  89   int i, j, repeat;
  90   unsigned int values[KEYS_COUNT];
  91
  92   dbgprintf ("Worker %p started\n", gl_thread_self_pointer ());
  93
  94   /* Initialize the per-thread storage.  */
  95   for (i = 0; i < KEYS_COUNT; i++)
  96     {
  97       values[i] = (((unsigned int) rand () >> 3) % 1000000) * THREAD_COUNT + id;
  98       /* Hopefully no arithmetic overflow.  */
  99       if ((values[i] % THREAD_COUNT) != id)
 100         abort ();
 101     }
 102   perhaps_yield ();
 103
 104   /* Verify that the initial value is NULL.  */
 105   dbgprintf ("Worker %p before initial verify\n", gl_thread_self_pointer ());
 106   for (i = 0; i < KEYS_COUNT; i++)
 107     if (gl_tls_get (mykeys[i]) != NULL)
 108       abort ();
 109   dbgprintf ("Worker %p after  initial verify\n", gl_thread_self_pointer ());
 110   perhaps_yield ();
 111
 112   /* Initialize the per-thread storage.  */
 113   dbgprintf ("Worker %p before first tls_set\n", gl_thread_self_pointer ());
 114   for (i = 0; i < KEYS_COUNT; i++)
 115     {
 116       unsigned int *ptr = (unsigned int *) malloc (sizeof (unsigned int));
 117       *ptr = values[i];
 118       gl_tls_set (mykeys[i], ptr);
 119     }
 120   dbgprintf ("Worker %p after  first tls_set\n", gl_thread_self_pointer ());
 121   perhaps_yield ();
 122
 123   /* Shuffle around the pointers.  */
 124   for (repeat = REPEAT_COUNT; repeat > 0; repeat--)
 125     {
 126       dbgprintf ("Worker %p doing value swapping\n", gl_thread_self_pointer ());
 127       i = ((unsigned int) rand () >> 3) % KEYS_COUNT;
 128       j = ((unsigned int) rand () >> 3) % KEYS_COUNT;
 129       if (i != j)
 130         {
 131           void *vi = gl_tls_get (mykeys[i]);
 132           void *vj = gl_tls_get (mykeys[j]);
 133
 134           gl_tls_set (mykeys[i], vj);
 135           gl_tls_set (mykeys[j], vi);
 136         }
 137       perhaps_yield ();
 138     }
 139
 140   /* Verify that all the values are from this thread.  */
 141   dbgprintf ("Worker %p before final verify\n", gl_thread_self_pointer ());
 142   for (i = 0; i < KEYS_COUNT; i++)
 143     if ((*(unsigned int *) gl_tls_get (mykeys[i]) % THREAD_COUNT) != id)
 144       abort ();
 145   dbgprintf ("Worker %p after  final verify\n", gl_thread_self_pointer ());
 146   perhaps_yield ();
 147
 148   dbgprintf ("Worker %p dying.\n", gl_thread_self_pointer ());
 149   return NULL;
 150 }
 151
 152 static void
 153 test_tls (void)
 154 {
 155   int pass, i;
 156
 157   for (pass = 0; pass < 2; pass++)
 158     {
 159       gl_thread_t threads[THREAD_COUNT];
 160
 161       if (pass == 0)
 162         for (i = 0; i < KEYS_COUNT; i++)
 163           gl_tls_key_init (mykeys[i], free);
 164       else
 165         for (i = KEYS_COUNT - 1; i >= 0; i--)
 166           gl_tls_key_init (mykeys[i], free);
 167
 168       /* Spawn the threads.  */
 169       for (i = 0; i < THREAD_COUNT; i++)
 170         threads[i] = gl_thread_create (worker_thread, NULL);
 171
 172       /* Wait for the threads to terminate.  */
 173       for (i = 0; i < THREAD_COUNT; i++)
 174         gl_thread_join (threads[i], NULL);
 175
 176       for (i = 0; i < KEYS_COUNT; i++)
 177         gl_tls_key_destroy (mykeys[i]);
 178     }
 179 }
 180
 181
 182 /* -------------------------------------------------------------------------- */
 183
 184 int
 185 main ()
 186 {
 187 #if TEST_PTH_THREADS
 188   if (!pth_init ())
 189     abort ();
 190 #endif
 191
 192   printf ("Starting test_tls ..."); fflush (stdout);
 193   test_tls ();
 194   printf (" OK\n"); fflush (stdout);
 195
 196   return 0;
 197 }
 198
 199 #else
 200
 201 /* No multithreading available.  */
 202
 203 #include <stdio.h>
 204
 205 int
 206 main ()
 207 {
 208   fputs ("Skipping test: multithreading not enabled\n", stderr);
 209   return 77;
 210 }
 211
 212 #endif