ACE/examples/Threads/barrier1.cpp

   1 // This test program illustrates how the ACE barrier synchronization
   2 // mechanisms work.
   3
   4 #include "ace/OS_main.h"
   5 #include "ace/Barrier.h"
   6 #include "ace/Thread_Manager.h"
   7 #include "ace/Service_Config.h"
   8
   9
  10 #if defined (ACE_HAS_THREADS)
  11
  12 struct Tester_Args
  13   // = TITLE
  14   //     These arguments are passed into each test thread.
  15 {
  16   Tester_Args (ACE_Barrier &tb, int i)
  17     : tester_barrier_ (tb),
  18       n_iterations_ (i) {}
  19
  20   ACE_Barrier &tester_barrier_;
  21   // Reference to the tester barrier.  This controls each miteration of
  22   // the tester function running in every thread.
  23
  24   int n_iterations_;
  25   // Number of iterations to run.
  26 };
  27
  28 // Iterate <n_iterations> time printing off a message and "waiting"
  29 // for all other threads to complete this iteration.
  30
  31 static void *
  32 tester (Tester_Args *args)
  33 {
  34   for (int iterations = 1;
  35        iterations <= args->n_iterations_;
  36        iterations++)
  37     {
  38       ACE_DEBUG ((LM_DEBUG, "(%t) in iteration %d\n", iterations));
  39
  40       // Block until all other threads have waited, then continue.
  41       args->tester_barrier_.wait ();
  42     }
  43
  44   return 0;
  45 }
  46
  47 // Default number of threads to spawn.
  48 static const int DEFAULT_ITERATIONS = 5;
  49
  50 int
  51 ACE_TMAIN (int argc, ACE_TCHAR *argv[])
  52 {
  53   ACE_Service_Config daemon (argv[0]);
  54
  55   int n_threads = argc > 1 ? ACE_OS::atoi (argv[1]) : ACE_DEFAULT_THREADS;
  56   int n_iterations = argc > 2 ? ACE_OS::atoi (argv[2]) : DEFAULT_ITERATIONS;
  57
  58   ACE_Barrier tester_barrier (n_threads);
  59
  60   Tester_Args args (tester_barrier, n_iterations);
  61
  62   if (ACE_Thread_Manager::instance ()->spawn_n
  63       (int(n_threads), ACE_THR_FUNC (tester),
  64        (void *) &args, THR_NEW_LWP | THR_DETACHED) == -1)
  65     ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "spawn_n"), 1);
  66
  67   // Wait for all the threads to reach their exit point.
  68   ACE_Thread_Manager::instance ()->wait ();
  69
  70   ACE_DEBUG ((LM_DEBUG, "(%t) done\n"));
  71   return 0;
  72 }
  73 #else
  74 int
  75 ACE_TMAIN (int, ACE_TCHAR *[])
  76 {
  77   ACE_ERROR ((LM_ERROR, "threads not supported on this platform\n"));
  78   return 0;
  79 }
  80 #endif /* ACE_HAS_THREADS */