path: root/tests/Priority_Task_Test.cpp

// $Id$

// ============================================================================
//
// = LIBRARY
//    tests
//
// = FILENAME
//    Priority_Task_Test.cpp
//
// = DESCRIPTION
//      This is a simple test to illustrate the priority mechanism of
//      ACE Tasks.  The test requires no options, but the -d option
//      enables LM_DEBUG output.
//
// = AUTHOR
//    Carlos O'Ryan <coryan@cs.wustl.edu>
//
// ============================================================================

#include "test_config.h"
#include "ace/Task.h"
#include "ace/Sched_Params.h"

ACE_RCSID(tests, Priority_Task_Test, "$Id$")

static const ACE_TCHAR *usage = ACE_TEXT ("usage: %s [-d]\n");

#if defined (ACE_HAS_THREADS)

class Priority_Task : public ACE_Task<ACE_MT_SYNCH>
{
  // = TITLE
  //   A simple Task that runs itself a different priorities.
  //
  // = DESCRIPTION
  //   This task uses the void* argument on open to run the svc()
  //   method at a different priority. The point is execise the thread
  //   priority features of ACE.
public:
  Priority_Task (void);
  // The constructor

  int open (void *);
  // Receives the priority and run svc() on a separate thread at that
  // priority.

  int svc (void);
  // Runs on a separate thread an checks the priority.

  int succeeded (void) { return error_ == 0; }
  // Returns 1 if priority was set properly, 0 otherwise.

private:
  int priority_;
  u_int error_;
};

Priority_Task::Priority_Task (void)
  : ACE_Task<ACE_MT_SYNCH> (ACE_Thread_Manager::instance ()),
    priority_ (0),
    error_ (0)
{
}

int
Priority_Task::open (void *arg)
{
  this->priority_ = *(int *) arg;

  long flags = THR_NEW_LWP;

  // To get FIFO scheduling with PTHREADS.
  ACE_SET_BITS (flags,
                THR_SCHED_FIFO);

  // Become an active object.
  if (this->activate (flags,
                      1,
                      0,
                      this->priority_) == -1)
    {
      // On Linux, for example, only the superuser can set the policy
      // to other than ACE_SCHED_OTHER.  But with ACE_SCHED_OTHER,
      // there is only one thread priority value, for example, 0.  So,
      // let the superuser run an interesting test, but for other
      // users use the minimum ACE_SCHED_OTHER thread priority.

      long fallback_priority =
        ACE_Sched_Params::priority_min (ACE_SCHED_OTHER,
                                        ACE_SCOPE_THREAD);

      ACE_DEBUG ((LM_DEBUG,
                  ACE_TEXT ("(%t) task activation at priority %d with ")
                  ACE_TEXT ("flags 0x%X failed; retry at priority %d with ")
                  ACE_TEXT ("flags 0x%X (errno is %d%p)\n"),
                  this->priority_,
                  flags,
                  fallback_priority,
                  THR_NEW_LWP,
                  errno,
                  ACE_TEXT ("")));

      flags = THR_NEW_LWP;
      this->priority_ = fallback_priority;

      if (this->activate (flags,
                          1,
                          1,
                          this->priority_) == -1)
        {
#if !defined (ACE_HAS_WINCE)
          if (ACE_OS::last_error () == EPERM)
            ACE_ERROR_RETURN ((LM_ERROR,
                               ACE_TEXT ("Insufficient privilege to run this test.\n")),
                              -1);
          else
#endif  // ACE_HAS_WINCE
            ACE_DEBUG ((LM_ERROR,
                        ACE_TEXT ("(%t) task activation at priority %d failed, ")
                        ACE_TEXT ("exiting!\n%a"),
                        this->priority_,
                        -1));
        }
    }
  return 0;
}

int
Priority_Task::svc (void)
{
  ACE_hthread_t thr_handle;
  ACE_Thread::self (thr_handle);
  int prio;

  if (ACE_Thread::getprio (thr_handle, prio) == -1)
  {
    if (errno == ENOTSUP)
    {
      ACE_DEBUG((LM_DEBUG,
                 ACE_TEXT ("getprior not supported on this platform\n")
               ));
      return 0;
    }
    ACE_ERROR_RETURN ((LM_ERROR,
                       ACE_TEXT ("%p\n"),
                       ACE_TEXT ("getprio failed")),
                      -1);
  }

  if (prio == this->priority_)
    ACE_DEBUG ((LM_DEBUG,
                ACE_TEXT ("(%t) actual prio of %d equals desired priority\n"),
                prio));
  else
    {
      ACE_DEBUG ((LM_ERROR,
                  ACE_TEXT ("(%t) actual prio = %d, desired priority_ = %d!\n"),
                  prio,
                  this->priority_));
      ++error_;
    }

  return 0;
}

#endif /* ACE_HAS_THREADS */

int
run_main (int argc, ACE_TCHAR *argv[])
{
  ACE_START_TEST (ACE_TEXT ("Priority_Task_Test"));

  if (argc <= 1)
    // Disable LM_DEBUG messages.
    ACE_Log_Msg::instance ()->priority_mask
      (ACE_Log_Msg::instance ()->priority_mask () &~ LM_DEBUG);
  else if (argc == 2)
    {
      if (ACE_OS::strcmp (argv[1],
                          ACE_TEXT ("-d")) != 0)
        ACE_ERROR_RETURN ((LM_ERROR,
                           usage,
                           argv [0]),
                          -1);
      // else -d option: don't disable LM_DEBUG messages
    }
  else
    ACE_ERROR_RETURN ((LM_ERROR,
                       usage,
                       argv [0]),
                      -1);

  int status = 0;

#if defined (ACE_HAS_THREADS)

  Priority_Task tasks[ACE_MAX_ITERATIONS];

  size_t i;

  // Spawn off ACE_MAX_ITERATIONS of tasks, passing each one their
  // iteration number as their priority.

  // NOTE: on Solaris, for example, this requests the min FIFO
  // priority.  But, this test doesn't use the Realtime scheduling
  // class.  The FIFO priorities are used because they're all
  // nonnegative.

  ACE_Sched_Priority_Iterator priority (ACE_SCHED_FIFO,
                                        ACE_SCOPE_THREAD);

  for (i = 0; i < ACE_MAX_ITERATIONS; i++)
    {
      int p = priority.priority ();
      if (tasks[i].open ((void *) &p) == -1)
        break; // Out of enclosing loop.

      // If there are more priorities get the next one...
      if (priority.more ())
        priority.next ();
    }

  ACE_DEBUG ((LM_DEBUG,
              ACE_TEXT ("(%t) %d tasks spawned, wait for them to exit . . .\n"),
              ACE_MAX_ITERATIONS));

  // Wait for all tasks to exit.
  ACE_Thread_Manager::instance ()->wait ();

  for (i = 0; i < ACE_MAX_ITERATIONS; i++)
    if (!tasks[i].succeeded ())
      {
        ++status;
        break;
      }

#else
  ACE_ERROR ((LM_DEBUG,
              ACE_TEXT ("threads not supported on this platform\n")));
#endif /* ACE_HAS_THREADS */

  // Re-enable LM_DEBUG messages.
  ACE_Log_Msg::instance ()->priority_mask
    (ACE_Log_Msg::instance ()->priority_mask () | LM_DEBUG);

  ACE_END_TEST;
  return status;
}