gdb/testsuite/gdb.threads/tls.c

   1 /* BeginSourceFile tls.c
   2
   3   This file creates and deletes threads. It uses thread local storage
   4   variables too. */
   5
   6 #include <unistd.h>
   7 #include <stdlib.h>
   8 #include <stdio.h>
   9 #include <assert.h>
  10 #include <pthread.h>
  11 #include <semaphore.h>
  12 #include <errno.h>
  13
  14 #define N_THREADS 3
  15
  16 /* Uncomment to turn on debugging output */
  17 /*#define START_DEBUG*/
  18
  19 /* Thread-local storage.  */
  20 __thread int a_thread_local;
  21 __thread int another_thread_local;
  22
  23 /* Global variable just for info addr in gdb.  */
  24 int a_global;
  25
  26 /* Print the results of thread-local storage.  */
  27 int thread_local_val[ N_THREADS ];
  28 int another_thread_local_val[ N_THREADS ];
  29
  30 /* Semaphores to make sure the threads are alive when we print the TLS
  31    variables from gdb.  */
  32 sem_t tell_main, tell_thread;
  33
  34
  35 void print_error ()
  36 {
  37   switch (errno)
  38   {
  39     case EAGAIN:
  40       fprintf (stderr, "EAGAIN\n");
  41       break;
  42     case EINTR:
  43       fprintf (stderr, "EINTR\n");
  44       break;
  45     case EINVAL:
  46       fprintf (stderr, "EINVAL\n");
  47       break;
  48     case ENOSYS:
  49       fprintf (stderr, "ENOSYS\n");
  50       break;
  51     case ENOENT:
  52       fprintf (stderr, "ENOENT\n");
  53       break;
  54     case EDEADLK:
  55       fprintf (stderr, "EDEADLK\n");
  56       break;
  57     default:
  58       fprintf (stderr, "Unknown error\n");
  59       break;
  60    }
  61 }
  62
  63 /* Routine for each thread to run, does nothing.  */
  64 void *spin( vp )
  65     void * vp;
  66 {
  67     int me = (long) vp;
  68     int i;
  69
  70     /* Use a_global. */
  71     a_global++;
  72
  73     a_thread_local = 0;
  74     another_thread_local = me;
  75     for( i = 0; i <= me; i++ ) {
  76         a_thread_local += i;
  77     }
  78
  79     another_thread_local_val[me] = another_thread_local;
  80     thread_local_val[ me ] = a_thread_local; /* here we know tls value */
  81
  82     if (sem_post (&tell_main) == -1)
  83      {
  84         fprintf (stderr, "th %d post on sem tell_main failed\n", me);
  85         print_error ();
  86         return;
  87      }
  88 #ifdef START_DEBUG
  89     fprintf (stderr, "th %d post on tell main\n", me);
  90 #endif
  91
  92     while (1)
  93       {
  94 #ifdef START_DEBUG
  95         fprintf (stderr, "th %d start wait on tell_thread\n", me);
  96 #endif
  97         if (sem_wait (&tell_thread) == 0)
  98           break;
  99
 100         if (errno == EINTR)
 101           {
 102 #ifdef START_DEBUG
 103             fprintf (stderr, "th %d wait tell_thread got EINTR, rewaiting\n", me);
 104 #endif
 105             continue;
 106           }
 107         else
 108           {
 109             fprintf (stderr, "th %d wait on sem tell_thread failed\n", me);
 110             print_error ();
 111             return;
 112          }
 113       }
 114
 115 #ifdef START_DEBUG
 116       fprintf (stderr, "th %d Wait on tell_thread\n", me);
 117 #endif
 118
 119 }
 120
 121 void
 122 do_pass()
 123 {
 124     int i;
 125     pthread_t t[ N_THREADS ];
 126     int err;
 127
 128     for( i = 0; i < N_THREADS; i++)
 129     {
 130         thread_local_val[i] = 0;
 131         another_thread_local_val[i] = 0;
 132     }
 133
 134     if (sem_init (&tell_main, 0, 0) == -1)
 135     {
 136       fprintf (stderr, "tell_main semaphore init failed\n");
 137       return;
 138     }
 139
 140     if (sem_init (&tell_thread, 0, 0) == -1)
 141     {
 142       fprintf (stderr, "tell_thread semaphore init failed\n");
 143       return;
 144     }
 145
 146     /* Start N_THREADS threads, then join them so that they are terminated.  */
 147     for( i = 0; i < N_THREADS; i++ )
 148      {
 149         err = pthread_create( &t[i], NULL, spin, (void *) (long) i );
 150         if( err != 0 ) {
 151             fprintf(stderr, "Error in thread %d create\n", i );
 152         }
 153      }
 154
 155     for( i = 0; i < N_THREADS; i++ )
 156       {
 157         while (1)
 158           {
 159 #ifdef START_DEBUG
 160             fprintf (stderr, "main %d start wait on tell_main\n", i);
 161 #endif
 162             if (sem_wait (&tell_main) == 0)
 163               break;
 164
 165             if (errno == EINTR)
 166               {
 167 #ifdef START_DEBUG
 168                 fprintf (stderr, "main %d wait tell_main got EINTR, rewaiting\n", i);
 169 #endif
 170                 continue;
 171               }
 172             else
 173               {
 174                 fprintf (stderr, "main %d wait on sem tell_main failed\n", i);
 175                 print_error ();
 176                 return;
 177               }
 178             }
 179        }
 180
 181 #ifdef START_DEBUG
 182     fprintf (stderr, "main done waiting on tell_main\n");
 183 #endif
 184
 185     i = 10;  /* Here all threads should be still alive. */
 186
 187     for( i = 0; i < N_THREADS; i++ )
 188      {
 189        if (sem_post (&tell_thread) == -1)
 190         {
 191            fprintf (stderr, "main %d post on sem tell_thread failed\n", i);
 192            print_error ();
 193            return;
 194         }
 195 #ifdef START_DEBUG
 196       fprintf (stderr, "main %d post on tell_thread\n", i);
 197 #endif
 198      }
 199
 200     for( i = 0; i < N_THREADS; i++ )
 201      {
 202         err = pthread_join(t[i], NULL );
 203         if( err != 0 )
 204          {
 205            fprintf (stderr, "error in thread %d join\n", i );
 206          }
 207     }
 208
 209     i = 10;  /* Null line for setting bpts on. */
 210
 211 }
 212
 213 int
 214 main()
 215 {
 216    do_pass ();
 217
 218    return 0;  /* Set breakpoint here before exit. */
 219 }
 220
 221 /* EndSourceFile */