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
  20 #if defined (ACE_HAS_THREADS)
  21
  22 struct Tester_Args
  23   // = TITLE
  24   //     These arguments are passed into each test thread.
  25 {
  26   Tester_Args (ACE_Barrier &tb, int i)
  27     : tester_barrier_ (tb),
  28     n_iterations_ (i) {}
  29
  30   ACE_Barrier &tester_barrier_;
  31   // Reference to the tester barrier.  This controls each iteration
  32   // of the tester function running in every thread.
  33
  34   int n_iterations_;
  35   // Number of iterations to run.
  36 };
  37
  38 // Iterate <n_iterations> time printing off a message and "waiting"
  39 // for all other threads to complete this iteration.
  40
  41 static void *
  42 wait_tester (Tester_Args *args)
  43 {
  44   for (int iterations = 1;
  45        iterations <= args->n_iterations_;
  46        iterations++)
  47     {
  48       ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("(%t) in iteration %d\n"),
  49                   iterations));
  50
  51       // Block until all other threads have waited, then continue.
  52       if (args->tester_barrier_.wait () != 0)
  53         ACE_ERROR ((LM_ERROR, ACE_TEXT ("(%t) %p\n"),
  54                     ACE_TEXT ("wait failed")));
  55     }
  56
  57   return 0;
  58 }
  59
  60 // Wait on the barrier, expecting it to be shut down before completing
  61 // the wait.
  62
  63 static void *
  64 shut_tester (Tester_Args *args)
  65 {
  66   if (args->tester_barrier_.wait () == 0)
  67     ACE_ERROR ((LM_ERROR,
  68                 ACE_TEXT ("(%t) wait succeeded, should have shut down\n")));
  69   else if (errno != ESHUTDOWN)
  70     ACE_ERROR ((LM_ERROR,
  71                 ACE_TEXT ("(%t) wait failed, expecting ESHUTDOWN, %p\n"),
  72                 ACE_TEXT ("got")));
  73   return 0;
  74 }
  75
  76 #endif /* ACE_HAS_THREADS */
  77
  78 int
  79 run_main (int, ACE_TCHAR *[])
  80 {
  81   ACE_START_TEST (ACE_TEXT ("Barrier_Test"));
  82
  83 #if defined (ACE_HAS_THREADS)
  84   int n_threads = ACE_MAX_THREADS;
  85   int n_iterations = ACE_MAX_ITERATIONS;
  86
  87   ACE_Barrier tester_barrier (n_threads);
  88
  89   Tester_Args args (tester_barrier, n_iterations);
  90
  91   for (size_t iteration_count = 0;
  92        iteration_count < ACE_MAX_ITERATIONS;
  93        iteration_count++)
  94     {
  95       ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("starting iteration %d\n"),
  96                   iteration_count));
  97
  98       if (ACE_Thread_Manager::instance ()->spawn_n
  99           (n_threads,
 100            (ACE_THR_FUNC) wait_tester,
 101            (void *) &args,
 102            THR_NEW_LWP | THR_JOINABLE) == -1)
 103
 104         ACE_ERROR_RETURN ((LM_ERROR, ACE_TEXT ("%p\n"),
 105                            ACE_TEXT ("spawn_n")), 1);
 106
 107       ACE_Thread_Manager::instance ()->wait ();
 108     }
 109
 110   // Now test ACE_Barrier shutdown. Set up a barrier for n_threads, and start
 111   // n_threads - 1 threads to wait, then shut the barrier down.
 112   ACE_Barrier shut_barrier (n_threads);
 113   Tester_Args shut_args (shut_barrier, 1);
 114   ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("Starting shutdown test threads\n")));
 115   if (ACE_Thread_Manager::instance ()->spawn_n
 116       (n_threads - 1,
 117        (ACE_THR_FUNC) shut_tester,
 118        (void *) &shut_args,
 119        THR_NEW_LWP | THR_JOINABLE) == -1)
 120     ACE_ERROR_RETURN ((LM_ERROR, ACE_TEXT ("%p\n"), ACE_TEXT ("spawn_n")), 1);
 121
 122   shut_barrier.shutdown ();
 123   ACE_Thread_Manager::instance ()->wait ();
 124
 125   ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("test done\n")));
 126 #else
 127   ACE_ERROR ((LM_INFO,
 128               ACE_TEXT ("threads not supported on this platform\n")));
 129 #endif /* ACE_HAS_THREADS */
 130   ACE_END_TEST;
 131   return 0;
 132 }