gdb/testsuite/gdb.threads/create-fail.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2012-2015 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #define _GNU_SOURCE
  19 #include <pthread.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <sched.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <assert.h>
  26 #include <stdio.h>
  27 #include <sys/types.h>
  28 #include <dirent.h>
  29 #include <assert.h>
  30 #include <unistd.h>
  31
  32 /* Count the number of tasks/threads in the PID thread group.  */
  33
  34 static int
  35 count_tasks (pid_t pid)
  36 {
  37   char path[100];
  38   int count;
  39   DIR *d;
  40
  41   snprintf (path, sizeof (path), "/proc/%d/task/", (int) pid);
  42   d = opendir (path);
  43   if (d == NULL)
  44     return -1;
  45
  46   for (count = 0; readdir (d) != NULL; count++)
  47     ;
  48   closedir (d);
  49
  50   /* Account for '.' and '..'.  */
  51   assert (count > 2);
  52   return count - 2;
  53 }
  54
  55 pthread_attr_t attr[CPU_SETSIZE];
  56 pthread_t thr[CPU_SETSIZE];
  57
  58 static void *
  59 mythread (void *_arg)
  60 {
  61   return NULL;
  62 }
  63
  64 int
  65 main ()
  66 {
  67   int i;
  68
  69   for (i = 0; i < CPU_SETSIZE; i++)
  70     {
  71       cpu_set_t set;
  72       int ret;
  73
  74       pthread_attr_init (&attr[i]);
  75       CPU_ZERO_S (sizeof (set), &set);
  76       CPU_SET_S (i, sizeof (set), &set);
  77
  78       ret = pthread_attr_setaffinity_np (&attr[i], sizeof (set), &set);
  79       if (ret != 0)
  80         {
  81           fprintf (stderr, "set_affinity: %d: %s\n", ret, strerror (ret));
  82           exit (3);
  83         }
  84       ret = pthread_create (&thr[i], &attr[i], mythread, NULL);
  85       /* Should fail with EINVAL at some point.  */
  86       if (ret != 0)
  87         {
  88           unsigned long t;
  89
  90           fprintf (stderr, "pthread_create: %d: %s\n", ret, strerror (ret));
  91
  92           /* Wait for all threads to exit.  pthread_create spawns a
  93              clone thread even in the failing case, as it can only try
  94              to set the affinity after creating the thread.  That new
  95              thread is immediately canceled (because setting the
  96              affinity fails), by killing it with a SIGCANCEL signal,
  97              which may end up in pthread_cancel/unwind paths, which
  98              may trigger a libgcc_s.so load, making the thread hit the
  99              solib-event breakpoint.  Now, if we would let the program
 100              exit without waiting, sometimes it would happen that the
 101              inferior exits just while we're handling the solib-event,
 102              resulting in errors being thrown due to failing ptrace
 103              call fails (with ESCHR), breaking the test.  */
 104           t = 16;
 105           while (count_tasks (getpid ()) > 1)
 106             {
 107               usleep (t);
 108
 109               if (t < 256)
 110                 t *= 2;
 111             }
 112
 113           /* Normal exit, because this is what we are expecting.  */
 114           exit (0);
 115         }
 116     }
 117
 118   /* Should not normally be reached.  */
 119   exit (1);
 120 }