Our Task object executes in one or more threads and reads from the message queue it contains.

#include "ace/Task.h"

/*
  Like the thread-pool server tutorial, we'll derive from ACE_Task<>.
  Our goal here is to show off the ACE_Message_Queue and the best way
  to do that is to use one to pass data between threads.  The easiest
  way to create threads is with ACE_Task<>
 */
class Task : public ACE_Task < ACE_MT_SYNCH >
{
public:

  typedef ACE_Task < ACE_MT_SYNCH > inherited;
    
    /*
      The constructor/destructor are simple but take care of some
      necessary housekeeping.
    */
    Task (void);
   ~Task (void);

  /*
    To make our Task<> derivative look more like other ACE objects
    I've added an open() method.  It will take care of activate()ing
    the object.
  */
  int open (int threads = 1);

  /*
    Our worker method
  */
  int svc (void);

  /*
    All we'll do here is print a message to the user.
  */
  int close (u_long flags = 0);

protected:
    /*
      Just to be clever, I'll use an ACE_Barrier to cause the threads
      to sync in svc() before doing any real work.
    */
    ACE_Barrier *barrier_;
};

The only thing here that we didn't see in the thread-pool server is the ACE_Barrier. The application logic really doesn't need it but it is a handy way to synchronize the threads at the beginning of svc(). In testing I found that if I didn't sync svc(), the first thread to get activated would tend to get all of the messages before the other threads came alive.