nptl/tst-default-attr.c

   1 /* Verify that pthread_[gs]etattr_default_np work correctly.
   2
   3    Copyright (C) 2013-2024 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <pthread.h>
  21 #include <stdio.h>
  22 #include <stdint.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <stdbool.h>
  27
  28 #define RETURN_IF_FAIL(f, ...) \
  29   ({                                                                          \
  30     int ret = f (__VA_ARGS__);                                                \
  31     if (ret != 0)                                                             \
  32       {                                                                       \
  33         printf ("%s:%d: %s returned %d (errno = %d)\n", __FILE__, __LINE__,   \
  34                 #f, ret, errno);                                              \
  35         return ret;                                                           \
  36       }                                                                       \
  37   })
  38
  39 static int (*verify_result) (pthread_attr_t *);
  40 static size_t stacksize = 1024 * 1024;
  41 static size_t guardsize;
  42 static bool do_join = true;
  43 static int running = 0;
  44 static int detach_failed = 0;
  45 static pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
  46 static pthread_cond_t c = PTHREAD_COND_INITIALIZER;
  47
  48 static void *
  49 thr (void *unused __attribute__ ((unused)))
  50 {
  51   pthread_attr_t attr;
  52   int ret;
  53
  54   memset (&attr, 0xab, sizeof attr);
  55   /* To verify that the pthread_setattr_default_np worked.  */
  56   if ((ret = pthread_getattr_default_np (&attr)) != 0)
  57     {
  58       printf ("pthread_getattr_default_np failed: %s\n", strerror (ret));
  59       goto out;
  60     }
  61
  62   if ((ret = (*verify_result) (&attr)) != 0)
  63     goto out;
  64
  65   memset (&attr, 0xab, sizeof attr);
  66   /* To verify that the attributes actually got applied.  */
  67   if ((ret = pthread_getattr_np (pthread_self (), &attr)) != 0)
  68     {
  69       printf ("pthread_getattr_default_np failed: %s\n", strerror (ret));
  70       goto out;
  71     }
  72
  73   ret = (*verify_result) (&attr);
  74
  75 out:
  76   if (!do_join)
  77     {
  78       pthread_mutex_lock (&m);
  79       running--;
  80       pthread_cond_signal (&c);
  81       pthread_mutex_unlock (&m);
  82
  83       detach_failed |= ret;
  84     }
  85
  86   return (void *) (uintptr_t) ret;
  87 }
  88
  89 static int
  90 run_threads (const pthread_attr_t *attr)
  91 {
  92   pthread_t t;
  93   void *tret = NULL;
  94
  95   RETURN_IF_FAIL (pthread_setattr_default_np, attr);
  96
  97   /* Run twice to ensure that the attributes do not get overwritten in the
  98      first run somehow.  */
  99   for (int i = 0; i < 2; i++)
 100     {
 101       RETURN_IF_FAIL (pthread_create, &t, NULL, thr, NULL);
 102       if (do_join)
 103         RETURN_IF_FAIL (pthread_join, t, &tret);
 104       else
 105         {
 106           pthread_mutex_lock (&m);
 107           running++;
 108           pthread_mutex_unlock (&m);
 109         }
 110
 111       if (tret != NULL)
 112         {
 113           puts ("Thread failed");
 114           return 1;
 115         }
 116     }
 117
 118   /* Stay in sync for detached threads and get their status.  */
 119   while (!do_join)
 120     {
 121       pthread_mutex_lock (&m);
 122       if (running == 0)
 123         {
 124           pthread_mutex_unlock (&m);
 125           break;
 126         }
 127       pthread_cond_wait (&c, &m);
 128       pthread_mutex_unlock (&m);
 129     }
 130
 131   return 0;
 132 }
 133
 134 static int
 135 verify_detach_result (pthread_attr_t *attr)
 136 {
 137   int state;
 138
 139   RETURN_IF_FAIL (pthread_attr_getdetachstate, attr, &state);
 140
 141   if (state != PTHREAD_CREATE_DETACHED)
 142     {
 143       puts ("failed to set detach state");
 144       return 1;
 145     }
 146
 147   return 0;
 148 }
 149
 150 static int
 151 do_detach_test (void)
 152 {
 153   pthread_attr_t attr;
 154
 155   do_join = false;
 156   RETURN_IF_FAIL (pthread_attr_init, &attr);
 157   RETURN_IF_FAIL (pthread_attr_setdetachstate, &attr, PTHREAD_CREATE_DETACHED);
 158
 159   RETURN_IF_FAIL (run_threads, &attr);
 160   return detach_failed;
 161 }
 162
 163 static int
 164 verify_affinity_result (pthread_attr_t *attr)
 165 {
 166   cpu_set_t cpuset;
 167
 168   RETURN_IF_FAIL (pthread_attr_getaffinity_np, attr, sizeof (cpuset), &cpuset);
 169   if (!CPU_ISSET (0, &cpuset))
 170     {
 171       puts ("failed to set cpu affinity");
 172       return 1;
 173     }
 174
 175   return 0;
 176 }
 177
 178 static int
 179 do_affinity_test (void)
 180 {
 181   pthread_attr_t attr;
 182
 183   RETURN_IF_FAIL (pthread_attr_init, &attr);
 184
 185   /* Processor affinity.  Like scheduling policy, this could fail if the user
 186      does not have the necessary privileges.  So we only spew a warning if
 187      pthread_create fails with EPERM.  A computer has at least one CPU.  */
 188   cpu_set_t cpuset;
 189   CPU_ZERO (&cpuset);
 190   CPU_SET (0, &cpuset);
 191   RETURN_IF_FAIL (pthread_attr_setaffinity_np, &attr, sizeof (cpuset), &cpuset);
 192
 193   int ret = run_threads (&attr);
 194
 195   if (ret == EPERM)
 196     {
 197       printf ("Skipping CPU Affinity test: %s\n", strerror (ret));
 198       return 0;
 199     }
 200   else if (ret != 0)
 201     return ret;
 202
 203   return 0;
 204 }
 205
 206 static int
 207 verify_sched_result (pthread_attr_t *attr)
 208 {
 209   int inherited, policy;
 210   struct sched_param param;
 211
 212   RETURN_IF_FAIL (pthread_attr_getinheritsched, attr, &inherited);
 213   if (inherited != PTHREAD_EXPLICIT_SCHED)
 214     {
 215       puts ("failed to set EXPLICIT_SCHED (%d != %d)");
 216       return 1;
 217     }
 218
 219   RETURN_IF_FAIL (pthread_attr_getschedpolicy, attr, &policy);
 220   if (policy != SCHED_RR)
 221     {
 222       printf ("failed to set SCHED_RR (%d != %d)\n", policy, SCHED_RR);
 223       return 1;
 224     }
 225
 226   RETURN_IF_FAIL (pthread_attr_getschedparam, attr, &param);
 227   if (param.sched_priority != 42)
 228     {
 229       printf ("failed to set sched_priority (%d != %d)\n",
 230               param.sched_priority, 42);
 231       return 1;
 232     }
 233
 234   return 0;
 235 }
 236
 237 static int
 238 do_sched_test (void)
 239 {
 240   pthread_attr_t attr;
 241
 242   RETURN_IF_FAIL (pthread_attr_init, &attr);
 243
 244   /* Scheduling policy.  Note that we don't always test these since it's
 245      possible that the user the tests run as don't have the appropriate
 246      privileges.  */
 247   RETURN_IF_FAIL (pthread_attr_setinheritsched, &attr, PTHREAD_EXPLICIT_SCHED);
 248   RETURN_IF_FAIL (pthread_attr_setschedpolicy, &attr, SCHED_RR);
 249
 250   struct sched_param param;
 251   param.sched_priority = 42;
 252   RETURN_IF_FAIL (pthread_attr_setschedparam, &attr, &param);
 253
 254   int ret = run_threads (&attr);
 255
 256   if (ret == EPERM)
 257     {
 258       printf ("Skipping Scheduler Attributes test: %s\n", strerror (ret));
 259       return 0;
 260     }
 261   else if (ret != 0)
 262     return ret;
 263
 264   return 0;
 265 }
 266
 267 static int
 268 verify_guardsize_result (pthread_attr_t *attr)
 269 {
 270   size_t guard;
 271
 272   RETURN_IF_FAIL (pthread_attr_getguardsize, attr, &guard);
 273
 274   if (guardsize != guard)
 275     {
 276       printf ("failed to set guardsize (%zu, %zu)\n", guardsize, guard);
 277       return 1;
 278     }
 279
 280   return 0;
 281 }
 282
 283 static int
 284 do_guardsize_test (void)
 285 {
 286   long int pagesize = sysconf (_SC_PAGESIZE);
 287   pthread_attr_t attr;
 288
 289   if (pagesize < 0)
 290     {
 291       printf ("sysconf failed: %s\n", strerror (errno));
 292       return 1;
 293     }
 294
 295   RETURN_IF_FAIL (pthread_getattr_default_np, &attr);
 296
 297   /* Increase default guardsize by a page.  */
 298   RETURN_IF_FAIL (pthread_attr_getguardsize, &attr, &guardsize);
 299   guardsize += pagesize;
 300   RETURN_IF_FAIL (pthread_attr_setguardsize, &attr, guardsize);
 301   RETURN_IF_FAIL (run_threads, &attr);
 302
 303   return 0;
 304 }
 305
 306 static int
 307 verify_stacksize_result (pthread_attr_t *attr)
 308 {
 309   size_t stack;
 310
 311   RETURN_IF_FAIL (pthread_attr_getstacksize, attr, &stack);
 312
 313   if (stacksize != stack)
 314     {
 315       printf ("failed to set default stacksize (%zu, %zu)\n", stacksize, stack);
 316       return 1;
 317     }
 318
 319   return 0;
 320 }
 321
 322 static int
 323 do_stacksize_test (void)
 324 {
 325   long int pagesize = sysconf (_SC_PAGESIZE);
 326   pthread_attr_t attr;
 327
 328   if (pagesize < 0)
 329     {
 330       printf ("sysconf failed: %s\n", strerror (errno));
 331       return 1;
 332     }
 333
 334   /* Perturb the size by a page so that we're not aligned on the 64K boundary.
 335      pthread_create does this perturbation on x86 to avoid causing the 64k
 336      aliasing conflict.  We want to prevent pthread_create from doing that
 337      since it is not consistent for all architectures.  */
 338   stacksize += pagesize;
 339
 340   RETURN_IF_FAIL (pthread_attr_init, &attr);
 341
 342   /* Run twice to ensure that we don't give a false positive.  */
 343   RETURN_IF_FAIL (pthread_attr_setstacksize, &attr, stacksize);
 344   RETURN_IF_FAIL (run_threads, &attr);
 345   stacksize *= 2;
 346   RETURN_IF_FAIL (pthread_attr_setstacksize, &attr, stacksize);
 347   RETURN_IF_FAIL (run_threads, &attr);
 348   return 0;
 349 }
 350
 351 /* We test each attribute separately because sched and affinity tests may need
 352    additional user privileges that may not be available during the test run.
 353    Each attribute test is a set of two functions, viz. a function to set the
 354    default attribute (do_foo_test) and another to verify its result
 355    (verify_foo_result).  Each test spawns a thread and checks (1) if the
 356    attribute values were applied correctly and (2) if the change in the default
 357    value reflected.  */
 358 static int
 359 do_test (void)
 360 {
 361   puts ("stacksize test");
 362   verify_result = verify_stacksize_result;
 363   RETURN_IF_FAIL (do_stacksize_test);
 364
 365   puts ("guardsize test");
 366   verify_result = verify_guardsize_result;
 367   RETURN_IF_FAIL (do_guardsize_test);
 368
 369   puts ("sched test");
 370   verify_result = verify_sched_result;
 371   RETURN_IF_FAIL (do_sched_test);
 372
 373   puts ("affinity test");
 374   verify_result = verify_affinity_result;
 375   RETURN_IF_FAIL (do_affinity_test);
 376
 377   puts ("detach test");
 378   verify_result = verify_detach_result;
 379   RETURN_IF_FAIL (do_detach_test);
 380
 381   return 0;
 382 }
 383
 384 #define TEST_FUNCTION do_test ()
 385 #include "../test-skeleton.c"