// $Id: page03.html,v 1.10 1999/09/22 03:13:46 jcej Exp $
#ifndef TASK_H
#define TASK_H
#include "ace/Task.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
class Task : public ACE_Task <ACE_MT_SYNCH>
{
public:
typedef ACE_Task <ACE_MT_SYNCH> inherited;
Task (size_t n_threads);
~Task (void);
int open (void * = 0);
int svc (void);
int close (u_long flags = 0);
protected:
ACE_Barrier barrier_;
size_t n_threads_;
};
#endif /* TASK_H */
// $Id: page03.html,v 1.10 1999/09/22 03:13:46 jcej Exp $
#include "task.h"
#include "block.h"
#include "data.h"
Task::Task (size_t n_threads)
: barrier_ (n_threads),
n_threads_ (n_threads)
{
ACE_DEBUG ((LM_DEBUG,
"(%P|%t) Task ctor 0x%x\n",
(void *) this));
}
Task::~Task (void)
{
ACE_DEBUG ((LM_DEBUG,
"(%P|%t) Task dtor 0x%x\n",
(void *) this));
ACE_Message_Block *message;
this->getq (message);
message->release ();
}
int
Task::open (void *)
{
return this->activate (THR_NEW_LWP,
this->n_threads_);
}
int
Task::close (u_long flags)
{
ACE_DEBUG ((LM_DEBUG,
"(%P|%t) Task close 0x%x\n",
(void *) this));
return inherited::close (flags);
}
int
Task::svc (void)
{
this->barrier_.wait ();
ACE_DEBUG ((LM_DEBUG,
"(%P|%t) Task 0x%x starts in thread %d\n",
(void *) this,
ACE_Thread::self ()));
ACE_Message_Block *message;
for (;;)
{
if (this->getq (message) == -1)
ACE_ERROR_RETURN ((LM_ERROR,
"%p\n",
"getq"),
-1);
if (message->msg_type () == ACE_Message_Block::MB_HANGUP)
{
this->putq (message);
break;
}
const char *cp = message->rd_ptr ();
// Don't forget to skip the NULL we inserted
message->rd_ptr (ACE_OS::strlen (cp) + 1);
ACE_DEBUG ((LM_DEBUG,
"(%P|%t) Block 0x%x contains (%s)\n",
(void *) message,
cp));
/* Create a Data object into which we can extract the message
block contents. */
Data data;
/* Use the rd_ptr() to access the message block data. Note that
we've already moved it past the text string in the block. */
ACE_OS::memmove ((char *) &data,
message->rd_ptr (),
sizeof (data));
message->rd_ptr (sizeof (data)); // Move the rd_ptr() beyond the data.
/* Invoke a couple of method calls on the object we constructed. */
data.who_am_i ();
data.what_am_i ();
/* An alternate approach:
Data * data;
data = (Data *)message->rd_ptr();
data->who_am_i();
data->what_am_i();
message->rd_ptr(sizeof(Data));
Even though this cuts down on the number of copies &
constructions, I'm not real fond of it. You can get into
trouble in a hurry by treating memory blocks as multiple data
types... */
ACE_OS::sleep (ACE_Time_Value (0, 5000));
message->release ();
}
return 0;
}
Notice how we had to create a temporary Data object to copy the stuff out of the message block? Again, if there were non-trivial ctor/dtors involved then this wouldn't work at all.
Again, like Tutorial 10 we've skipped THR_DETACHED because we wait() for the threads to exit elsewhere.