ACE Tutorial 015
Building a protocol stream
A quick look at the Protocol_Task header...
// page12.html,v 1.13 1999/09/22 03:13:53 jcej Exp
#ifndef PROTOCOL_TASK_H
#define PROTOCOL_TASK_H
#include "ace/Task.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
/* A typical ACE_Task<> derivative that adds a few things appropriate
to protocol stacks. To keep things a little simpler, we prevent
activation of the task and just borrow the thread of control from
the calling method in all cases.
*/
class Protocol_Task : public ACE_Task<ACE_MT_SYNCH>
{
public:
typedef ACE_Task<ACE_MT_SYNCH> inherited;
Protocol_Task (void);
~Protocol_Task (void);
// open() is invoked when the task is inserted into the stream.
virtual int open (void *arg);
// close() is invoked when the stream is closed (flags will be set
// to '1') and when the svc() method exits (flags will be '0').
virtual int close (u_long flags);
// As data travels through the stream, the put() method of each task
// is invoked to keep the data moving along.
virtual int put (ACE_Message_Block *message,
ACE_Time_Value *timeout);
// We're obligated to provide this signature even though we won't be
// allowing this object to be activated.
virtual int svc (void);
protected:
// Called by put() or svc() as necessary to process a block of data.
int process (ACE_Message_Block *message,
ACE_Time_Value *timeout);
// Tasks on the writer (downstream) side of the stream are called
// upon to send() data that will ultimately go to the peer.
virtual int send (ACE_Message_Block *message,
ACE_Time_Value *timeout);
// Tasks on the reader (upstream) side will be receiving data that
// came from the peer.
virtual int recv (ACE_Message_Block *message,
ACE_Time_Value *timeout);
};
#endif /* PROTOCOL_TASK_H */
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