TAO_SHMIOP_Transport Class Reference

Specialization of the base TAO_Transport class to handle the SHMIOP protocol. More...

#include <SHMIOP_Transport.h>

Inheritance diagram for TAO_SHMIOP_Transport:

[legend]Collaboration diagram for TAO_SHMIOP_Transport:

[legend]List of all members.

Public Member Functions
	TAO_SHMIOP_Transport (TAO_SHMIOP_Connection_Handler *handler, TAO_ORB_Core *orb_core)
	Constructor.
	~TAO_SHMIOP_Transport (void)
	Default destructor.
virtual int	send_request (TAO_Stub *stub, TAO_ORB_Core *orb_core, TAO_OutputCDR &stream, TAO_Message_Semantics message_semantics, ACE_Time_Value *max_wait_time)
virtual int	send_message (TAO_OutputCDR &stream, TAO_Stub *stub=0, TAO_Message_Semantics message_semantics=TAO_Transport::TAO_TWOWAY_REQUEST, ACE_Time_Value *max_time_wait=0)
Protected Member Functions
Overridden Template Methods
These are implementations of template methods declared by TAO_Transport.
virtual ACE_Event_Handler *	event_handler_i (void)
virtual TAO_Connection_Handler *	connection_handler_i (void)
virtual ssize_t	send (iovec *iov, int iovcnt, size_t &bytes_transferred, const ACE_Time_Value *timeout=0)
	Write the complete Message_Block chain to the connection.
virtual ssize_t	recv (char *buf, size_t len, const ACE_Time_Value *s=0)
	Read len bytes from into buf.
virtual int	handle_input (TAO_Resume_Handle &rh, ACE_Time_Value *max_wait_time)
Private Attributes
TAO_SHMIOP_Connection_Handler *	connection_handler_

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Detailed Description

Specialization of the base TAO_Transport class to handle the SHMIOP protocol.

Definition at line 53 of file SHMIOP_Transport.h.

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Constructor & Destructor Documentation

TAO_BEGIN_VERSIONED_NAMESPACE_DECL TAO_SHMIOP_Transport::TAO_SHMIOP_Transport	(	TAO_SHMIOP_Connection_Handler *	handler,
		TAO_ORB_Core *	orb_core
	)

Constructor.

Definition at line 24 of file SHMIOP_Transport.cpp.

  : TAO_Transport (TAO_TAG_SHMEM_PROFILE,
                   orb_core),
    connection_handler_ (handler)
{
}

TAO_SHMIOP_Transport::~TAO_SHMIOP_Transport

(

void

)

Default destructor.

Definition at line 32 of file SHMIOP_Transport.cpp.

{
}

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Member Function Documentation

TAO_Connection_Handler * TAO_SHMIOP_Transport::connection_handler_i

(

void

)

[protected, virtual]

Implements TAO_Transport.

Definition at line 43 of file SHMIOP_Transport.cpp.

References connection_handler_.

{
  return this->connection_handler_;
}

ACE_Event_Handler * TAO_SHMIOP_Transport::event_handler_i

(

void

)

[protected, virtual]

Implements TAO_Transport.

Definition at line 37 of file SHMIOP_Transport.cpp.

References connection_handler_.

{
  return this->connection_handler_;
}

int TAO_SHMIOP_Transport::handle_input	(	TAO_Resume_Handle &	rh,
		ACE_Time_Value *	max_wait_time
	)			[protected, virtual]

Reimplemented from TAO_Transport.

Definition at line 112 of file SHMIOP_Transport.cpp.

References ACE_DEBUG, ACE_ERROR, ACE_Message_Block::DONT_DELETE, ACE_CDR::grow(), TAO_GIOP_Message_Base::header_length(), TAO_ORB_Core::input_cdr_dblock_allocator(), LM_DEBUG, LM_ERROR, TAO_ORB_Core::locking_strategy(), ACE_CDR::MAX_ALIGNMENT, ACE_CDR::mb_align(), ACE_Message_Block::MB_DATA, ACE_OS::memset(), TAO_Transport::messaging_object(), TAO_Queued_Data::missing_data(), TAO_Transport::orb_core_, recv(), TAO_debug_level, TAO_MAXBUFSIZE, and TAO_MISSING_DATA_UNDEFINED.

{
  if (TAO_debug_level > 3)
    {
      ACE_DEBUG ((LM_DEBUG,
                  "TAO (%P|%t) - SHMIOP_Transport[%d]::handle_input\n",
                  this->id ()));
    }

   // The buffer on the stack which will be used to hold the input
  // messages, compensate shrink due to alignment
  char buf [TAO_MAXBUFSIZE + ACE_CDR::MAX_ALIGNMENT];


#if defined (ACE_INITIALIZE_MEMORY_BEFORE_USE)
  (void) ACE_OS::memset (buf,
                         '\0',
                         sizeof buf);
#endif /* ACE_INITIALIZE_MEMORY_BEFORE_USE */

  // Create a data block
  ACE_Data_Block db (sizeof (buf),
                     ACE_Message_Block::MB_DATA,
                     buf,
                     this->orb_core_->input_cdr_buffer_allocator (),
                     this->orb_core_->locking_strategy (),
                     ACE_Message_Block::DONT_DELETE,
                     this->orb_core_->input_cdr_dblock_allocator ());

  // Create a message block
  ACE_Message_Block message_block (&db,
                                   ACE_Message_Block::DONT_DELETE,
                                   this->orb_core_->input_cdr_msgblock_allocator ());


  // Align the message block
  ACE_CDR::mb_align (&message_block);

  const size_t missing_header_data = this->messaging_object ()->header_length ();

  if (missing_header_data == 0)
    {
      return -1;
    }

  // .. do a read on the socket again.
  ssize_t bytes = 0;

  // As this used for transports where things are available in one
  // shot this looping should not create any problems.
  for (size_t m = missing_header_data;
       m != 0;
       m -= bytes)
    {
      bytes = 0; // reset

      // We would have liked to use something like a recv_n ()
      // here. But at the time when the code was written, the MEM_Stream
      // classes had poor support  for recv_n (). Till a day when we
      // get proper recv_n (), let us stick with this. The other
      // argument that can be said against this is that, this is the
      // bad layer in which this is being done ie. recv_n is
      // simulated. But...
      bytes = this->recv (message_block.wr_ptr (),
                          m,
                          max_wait_time);

      if (bytes == 0 ||
          bytes == -1)
        {
          return -1;
        }

      message_block.wr_ptr (bytes);
    }

    TAO_Queued_Data qd (&message_block);
    size_t mesg_length = 0;

    // Parse the incoming message for validity. The check needs to be
    // performed by the messaging objects.
    if (this->messaging_object ()->parse_next_message (qd,
                                                       mesg_length) == -1)
      return -1;

    if (qd.missing_data () == TAO_MISSING_DATA_UNDEFINED)
      {
        // parse/marshal error happened
        return -1;
      }

    if (message_block.length () > mesg_length)
      {
        // we read too much data
        return -1;
      }

    if (message_block.space () < qd.missing_data ())
      {
        size_t const message_size = message_block.length ()
                                  + qd.missing_data ();

        // reallocate buffer with correct size on heap
        if (ACE_CDR::grow (&message_block, message_size) == -1)
          {
            if (TAO_debug_level > 0)
              {
                ACE_ERROR ((LM_ERROR,
                 "TAO (%P|%t) - SHMIOP_Transport[%d]::handle_input, "
                 "error growing message buffer\n",
                 this->id () ));
              }
            return -1;
          }

      }

    // As this used for transports where things are available in one
    // shot this looping should not create any problems.
    for (size_t n = qd.missing_data ();
       n != 0;
       n -= bytes)
    {
        bytes = 0; // reset

      // We would have liked to use something like a recv_n ()
      // here. But at the time when the code was written, the MEM_Stream
      // classes had poor support  for recv_n (). Till a day when we
      // get proper recv_n (), let us stick with this. The other
      // argument that can be said against this is that, this is the
      // bad layer in which this is being done ie. recv_n is
      // simulated. But...
      bytes = this->recv (message_block.wr_ptr (),
                          n,
                          max_wait_time);

      if (bytes == 0 ||
          bytes == -1)
        {
          return -1;
        }

      message_block.wr_ptr (bytes);
    }

  qd.missing_data (0);

  // Now we have a full message in our buffer. Just go ahead and
  // process that
  if (this->process_parsed_messages (&qd, rh) == -1)
    {
      return -1;
    }

  return 0;
}

ssize_t TAO_SHMIOP_Transport::recv	(	char *	buf,
		size_t	len,
		const ACE_Time_Value *	s = 0
	)			[protected, virtual]

Read len bytes from into buf.

Implements TAO_Transport.

Definition at line 69 of file SHMIOP_Transport.cpp.

References ACE_DEBUG, ACE_TEXT, connection_handler_, LM_DEBUG, ACE_Svc_Handler<, >::peer(), and TAO_debug_level.

Referenced by handle_input().

{
  ssize_t n = 0;

  int read_break = 0;

  while (!read_break)
    {
      n = this->connection_handler_->peer ().recv (buf,
                                                   len,
                                                   max_wait_time);

      // If we get a EWOULBLOCK we try to read again.
      if (n == -1 && (errno == EAGAIN || errno == EWOULDBLOCK))
        {
          n = 0;
          continue;
        }

      // If there is anything else we just drop out of the loop.
      read_break = 1;
    }

  if (n == -1)
    {
      if (TAO_debug_level > 3 && errno != ETIME)
        {
          ACE_DEBUG ((LM_DEBUG,
                      ACE_TEXT ("TAO (%P|%t) -  SHMIOP_Transport::recv, %p \n"),
                      ACE_TEXT ("TAO - read message failure ")
                      ACE_TEXT ("recv_i () \n")));
        }
    }
  else if (n == 0)
    {
      n = -1;
    }
  return n;
}

ssize_t TAO_SHMIOP_Transport::send	(	iovec *	iov,
		int	iovcnt,
		size_t &	bytes_transferred,
		const ACE_Time_Value *	timeout = 0
	)			[protected, virtual]

Write the complete Message_Block chain to the connection.

Implements TAO_Transport.

Definition at line 49 of file SHMIOP_Transport.cpp.

{
  bytes_transferred = 0;
  for (int i = 0; i < iovcnt; ++i)
    {
      ssize_t retval =
        this->connection_handler_->peer ().send (iov[i].iov_base,
                                                 iov[i].iov_len,
                                                 max_wait_time);
      if (retval > 0)
        bytes_transferred += retval;
      if (retval <= 0)
        return retval;
    }
  return bytes_transferred;
}

int TAO_SHMIOP_Transport::send_message	(	TAO_OutputCDR &	stream,
		TAO_Stub *	stub = 0,
		TAO_Message_Semantics	message_semantics = TAO_Transport::TAO_TWOWAY_REQUEST,
		ACE_Time_Value *	max_time_wait = 0
	)			[virtual]

Definition at line 295 of file SHMIOP_Transport.cpp.

References ACE_DEBUG, ACE_TEXT, ACE_OutputCDR::begin(), LM_DEBUG, TAO_Transport::send_message_shared(), and TAO_debug_level.

{
  // Format the message in the stream first
  if (this->messaging_object_->format_message (stream) != 0)
    return -1;

  // Strictly speaking, should not need to loop here because the
  // socket never gets set to a nonblocking mode ... some Linux
  // versions seem to need it though.  Leaving it costs little.

  // This guarantees to send all data (bytes) or return an error.
  ssize_t n = this->send_message_shared (stub,
                                         message_semantics,
                                         stream.begin (),
                                         max_wait_time);

  if (n == -1)
    {
      if (TAO_debug_level)
        ACE_DEBUG ((LM_DEBUG,
                    ACE_TEXT ("TAO (%P|%t) closing transport %d after fault %p\n"),
                    this->id (),
                    ACE_TEXT ("send_message ()\n")));

      return -1;
    }

  return 1;
}

int TAO_SHMIOP_Transport::send_request	(	TAO_Stub *	stub,
		TAO_ORB_Core *	orb_core,
		TAO_OutputCDR &	stream,
		TAO_Message_Semantics	message_semantics,
		ACE_Time_Value *	max_wait_time
	)			[virtual]

Todo:

These methods IMHO should have more meaningful names. The names seem to indicate nothing.

Definition at line 273 of file SHMIOP_Transport.cpp.

References TAO_Transport::first_request_sent(), and TAO_Transport::orb_core().

{
  if (this->ws_->sending_request (orb_core,
                                  message_semantics) == -1)
    return -1;

  if (this->send_message (stream,
                          stub,
                          message_semantics,
                          max_wait_time) == -1)

    return -1;
  this->first_request_sent();

  return 0;
}

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Member Data Documentation

TAO_SHMIOP_Connection_Handler* TAO_SHMIOP_Transport::connection_handler_ [private]

The connection service handler used for accessing lower layer communication protocols.

Definition at line 105 of file SHMIOP_Transport.h.

Referenced by connection_handler_i(), event_handler_i(), and recv().

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The documentation for this class was generated from the following files:

• SHMIOP_Transport.h
• SHMIOP_Transport.cpp

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