path: root/examples/Threads/task_four.cpp

// $Id$

// The following test was written by Hamutal Yanay & Ari Erev's
// (Ari_Erev@comverse.com). 
//
// This test program test enhancements to the thread_manager and task
// classes.  The purpose of these enhancements was to allow the
// thread_manager to recognize the concept of an ACE_Task and to be
// able to group ACE_Tasks in groups.
//
// There are two main ACE_Tasks in this sample:
//
// Invoker_Task - is run from main (). It's purpose is to run a number of 
//                ACE_Tasks of type Worker_Task. The number can be specified
//                on the command line.
//                After starting the tasks, the Invoker_Task groups all the tasks
//                in one group and then uses the
//                num_tasks_in_group () to find out if the real number of tasks
//                that are now running (should be the same as the number of tasks
//                started).
//                It also, suspends and resumes all the threads in the group to
//                test the suspend_grp () and resume_grp () methods.
//                Then it waits for all the tasks to end.
// Worker_Task  - ACE_Tasks that are started by the Invoker_Task.
//                Each Worker_Task can start a number of threads.
//                The Worker_Task threads perform some work (iteration). The number
//                of the iterations can be specified on the command line.
//
// The command line syntax is:
//
// test_task   [num_tasks] [num_threads] [num_iterations]

#include "ace/Task.h"
#include "ace/Service_Config.h"


#if defined (ACE_HAS_THREADS)

#include "ace/Task.h"

class Invoker_Task : public ACE_Task<ACE_MT_SYNCH>
{
public:
  Invoker_Task (ACE_Thread_Manager *thr_mgr,
		int n_tasks,
		int n_threads,
		int n_iterations);
  virtual int svc (void);
  // creats <n_tasks> and wait for them to finish

private:
  int n_tasks_;
  // Number of tasks to start.
  int n_threads_;
  // Number of threads per task.
  int n_iterations_;
  // Number of iterations per thread.

  // = Not needed for this test.
  virtual int open (void *) { return 0; }
  virtual int close (u_long) { return 0; }
  virtual int put (ACE_Message_Block *, ACE_Time_Value *) { return 0; }
};

class Worker_Task : public ACE_Task<ACE_MT_SYNCH>
{
public:
  Worker_Task (ACE_Thread_Manager *thr_mgr,
	       int n_threads,
	       int n_iterations);  
  virtual int svc (void);
  // Does a small work...
  virtual int open (void * = NULL);
private:
  static int workers_count_;
  int index_;
  int n_threads_;
  int n_iterations_;

  // = Not needed for this test.
  virtual int close (u_long) { return 0; }
  virtual int put (ACE_Message_Block *, ACE_Time_Value *) { return 0; }
};

int Worker_Task::workers_count_ = 1;

Worker_Task::Worker_Task (ACE_Thread_Manager *thr_mgr, 
                          int n_threads,
                          int n_iterations)
  : n_threads_ (n_threads), 
    n_iterations_ (n_iterations), 
    ACE_Task<ACE_MT_SYNCH> (thr_mgr)
{
  index_ = workers_count_++;
}
 
int 
Worker_Task::open (void *)
{
  // Create worker threads.
  int rc = this->activate (THR_NEW_LWP, n_threads_, 0, 0, -1, this);

  if (rc == -1)
    ACE_ERROR ((LM_ERROR, "%p\n", "activate failed"));

  return rc;
}

int 
Worker_Task::svc (void)
{
  ACE_DEBUG ((LM_DEBUG, " (%t) in worker %d\n", index_));

  for (int iterations = 1; 
       iterations <= this->n_iterations_;
       iterations++)
    {
      ACE_DEBUG ((LM_DEBUG, " (%t) in iteration %d\n", iterations));
      ACE_OS::sleep (0);
    }

  ACE_DEBUG ((LM_DEBUG, " (%t) worker %d ends\n", index_));

  return 0;
}

Invoker_Task::Invoker_Task (ACE_Thread_Manager *thr_mgr, 
			    int n_tasks,
			    int n_threads,
			    int n_iterations)           
  : n_tasks_ (n_tasks), 
    n_threads_ (n_threads), 
    n_iterations_ (n_iterations),
    ACE_Task<ACE_MT_SYNCH> (thr_mgr)
{
  // Create worker threads.
  if (this->activate (THR_NEW_LWP, 1, 0, 0, -1, this) == -1)
    ACE_ERROR ((LM_ERROR, "%p\n", "activate failed"));
}
  
// Iterate <n_iterations> time printing off a message and "waiting"
// for all other threads to complete this iteration.

int 
Invoker_Task::svc (void) 
{  
  // Note that the ACE_Task::svc_run () method automatically adds us to
  // the Thread_Manager when the thread begins.

  ACE_Thread_Manager *thr_mgr = ACE_Service_Config::thr_mgr ();
  Worker_Task **pTask = new Worker_Task* [n_tasks_];
   
  for (int task = 0; 
       task < this->n_tasks_;
       task++)
    {
      ACE_DEBUG ((LM_DEBUG, " (%t) in task %d\n", task+1));
      pTask[task] = new Worker_Task (thr_mgr, n_threads_, n_iterations_);
      pTask[task]->open ();  
    }

  // Set all tasks to be one group
  ACE_DEBUG ((LM_DEBUG, " (%t) setting tasks group id\n"));
  for (task = 0; 
       task < this->n_tasks_;
       task++)
    if (thr_mgr->set_grp (pTask[task], 1) == -1)
      ACE_ERROR ((LM_DEBUG, " (%t) %p\n", "set_grp"));

  int nTasks = thr_mgr->num_tasks_in_group (1);
  cout << "Number of tasks in group 1: " << nTasks << endl;

  // Wait for 1 second and then suspend every thread in the group.
  ACE_OS::sleep (1);
  ACE_DEBUG ((LM_DEBUG, " (%t) suspending group\n"));
  if (thr_mgr->suspend_grp (1) == -1)
    ACE_ERROR ((LM_DEBUG, " (%t) %p\n", "suspend_grp"));

  // Wait for 5 more second and then resume every thread in the
  // group.
  ACE_OS::sleep (ACE_Time_Value (5));
  
  // @QTSK  This ACE_DEBUG statement blows us away! can't understand why
  ACE_DEBUG ((LM_DEBUG, " (%t) resuming group\n"));
  if (thr_mgr->resume_grp (1) == -1)
    ACE_ERROR ((LM_DEBUG, " (%t) %p\n", "resume_grp"));


  // Wait for all the tasks to reach their exit point.
  thr_mgr->wait ();

  // Note that the ACE_Task::svc_run () method automatically removes us
  // from the Thread_Manager when the thread exits.

  return 0;
}

// Default number of tasks and iterations.
static const int DEFAULT_TASKS = 4;
static const int DEFAULT_ITERATIONS = 5;

int 
main (int argc, char *argv[])
{
  int n_tasks = argc > 1 ? ACE_OS::atoi (argv[1]) : DEFAULT_TASKS;
  int n_threads = argc > 2 ? ACE_OS::atoi (argv[2]) : ACE_DEFAULT_THREADS;
  int n_iterations = argc > 3 ? ACE_OS::atoi (argv[3]) : DEFAULT_ITERATIONS;

  // Since ACE_Thread_Manager can only wait for all threads, we'll have
  // special manager for the Invoker_Task.
  ACE_Thread_Manager invoker_manager;

  Invoker_Task invoker (&invoker_manager, 
			n_tasks, 
			n_threads,
			n_iterations); 

  // Wait for 1 second and then suspend the invoker task
  ACE_OS::sleep (1);
  ACE_DEBUG ((LM_DEBUG, " (%t) suspending invoker task\n"));

  if (invoker_manager.suspend_task (&invoker) == -1)
    ACE_ERROR ((LM_DEBUG, " (%t) %p\n", "suspend_task"));

  // Wait for 5 more second and then resume the invoker task.
  ACE_OS::sleep (ACE_Time_Value (5));

  // @QTSK  This ACE_DEBUG statement blows us away! can't understand why
  ACE_DEBUG ((LM_DEBUG, " (%t) resuming invoker task\n"));
  if (invoker_manager.resume_task (&invoker) == -1)
    ACE_ERROR ((LM_DEBUG, " (%t) %p\n", "resume_task"));


  // Wait for all the threads to reach their exit point.
  invoker_manager.wait ();

  // @QTSK  This ACE_DEBUG statement blows us away! can't understand why
  ACE_DEBUG ((LM_DEBUG, " (%t) done\n"));
  return 0;
}
#else
int 
main (int, char *[])
{
  ACE_ERROR ((LM_ERROR, "threads not supported on this platform\n"));
  return 0;
}
#endif /* ACE_HAS_THREADS */