ACE/tests/Barrier_Test.cpp

   1
   2 //=============================================================================
   3 /**
   4  *  @file    Barrier_Test.cpp
   5  *
   6  *   This program illustrates how the ACE barrier synchronization
   7  *   mechanisms work.
   8  *
   9  *  @author Prashant Jain <pjain@cs.wustl.edu> and Doug Schmidt <d.schmidt@vanderbilt.edu>
  10  */
  11 //=============================================================================
  12
  13
  14 #include "test_config.h"
  15 #include "ace/Barrier.h"
  16 #include "ace/Thread_Manager.h"
  17
  18
  19 #if defined (ACE_HAS_THREADS)
  20
  21 struct Tester_Args
  22   // = TITLE
  23   //     These arguments are passed into each test thread.
  24 {
  25   Tester_Args (ACE_Barrier &tb, int i)
  26     : tester_barrier_ (tb),
  27     n_iterations_ (i) {}
  28
  29   ACE_Barrier &tester_barrier_;
  30   // Reference to the tester barrier.  This controls each iteration
  31   // of the tester function running in every thread.
  32
  33   int n_iterations_;
  34   // Number of iterations to run.
  35 };
  36
  37 // Iterate <n_iterations> time printing off a message and "waiting"
  38 // for all other threads to complete this iteration.
  39
  40 static void *
  41 wait_tester (Tester_Args *args)
  42 {
  43   for (int iterations = 1;
  44        iterations <= args->n_iterations_;
  45        iterations++)
  46     {
  47       ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("(%t) in iteration %d\n"),
  48                   iterations));
  49
  50       // Block until all other threads have waited, then continue.
  51       if (args->tester_barrier_.wait () != 0)
  52         ACE_ERROR ((LM_ERROR, ACE_TEXT ("(%t) %p\n"),
  53                     ACE_TEXT ("wait failed")));
  54     }
  55
  56   return 0;
  57 }
  58
  59 // Wait on the barrier, expecting it to be shut down before completing
  60 // the wait.
  61
  62 static void *
  63 shut_tester (Tester_Args *args)
  64 {
  65   if (args->tester_barrier_.wait () == 0)
  66     ACE_ERROR ((LM_ERROR,
  67                 ACE_TEXT ("(%t) wait succeeded, should have shut down\n")));
  68   else if (errno != ESHUTDOWN)
  69     ACE_ERROR ((LM_ERROR,
  70                 ACE_TEXT ("(%t) wait failed, expecting ESHUTDOWN, %p\n"),
  71                 ACE_TEXT ("got")));
  72   return 0;
  73 }
  74
  75 #endif /* ACE_HAS_THREADS */
  76
  77 int
  78 run_main (int, ACE_TCHAR *[])
  79 {
  80   ACE_START_TEST (ACE_TEXT ("Barrier_Test"));
  81
  82 #if defined (ACE_HAS_THREADS)
  83   int n_threads = ACE_MAX_THREADS;
  84   int n_iterations = ACE_MAX_ITERATIONS;
  85
  86   ACE_Barrier tester_barrier (n_threads);
  87
  88   Tester_Args args (tester_barrier, n_iterations);
  89
  90   for (size_t iteration_count = 0;
  91        iteration_count < ACE_MAX_ITERATIONS;
  92        iteration_count++)
  93     {
  94       ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("starting iteration %d\n"),
  95                   iteration_count));
  96
  97       if (ACE_Thread_Manager::instance ()->spawn_n
  98           (n_threads,
  99            (ACE_THR_FUNC) wait_tester,
 100            (void *) &args,
 101            THR_NEW_LWP | THR_JOINABLE) == -1)
 102
 103         ACE_ERROR_RETURN ((LM_ERROR, ACE_TEXT ("%p\n"),
 104                            ACE_TEXT ("spawn_n")), 1);
 105
 106       ACE_Thread_Manager::instance ()->wait ();
 107     }
 108
 109   // Now test ACE_Barrier shutdown. Set up a barrier for n_threads, and start
 110   // n_threads - 1 threads to wait, then shut the barrier down.
 111   ACE_Barrier shut_barrier (n_threads);
 112   Tester_Args shut_args (shut_barrier, 1);
 113   ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("Starting shutdown test threads\n")));
 114   if (ACE_Thread_Manager::instance ()->spawn_n
 115       (n_threads - 1,
 116        (ACE_THR_FUNC) shut_tester,
 117        (void *) &shut_args,
 118        THR_NEW_LWP | THR_JOINABLE) == -1)
 119     ACE_ERROR_RETURN ((LM_ERROR, ACE_TEXT ("%p\n"), ACE_TEXT ("spawn_n")), 1);
 120
 121   shut_barrier.shutdown ();
 122   ACE_Thread_Manager::instance ()->wait ();
 123
 124   ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("test done\n")));
 125 #else
 126   ACE_ERROR ((LM_INFO,
 127               ACE_TEXT ("threads not supported on this platform\n")));
 128 #endif /* ACE_HAS_THREADS */
 129   ACE_END_TEST;
 130   return 0;
 131 }