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ACE_WIN32_Asynch_Write_Dgram Class Reference

This class is a factory for starting off asynchronous writes on a UDP socket. More...

#include <WIN32_Asynch_IO.h>

Inheritance diagram for ACE_WIN32_Asynch_Write_Dgram:

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Collaboration diagram for ACE_WIN32_Asynch_Write_Dgram:

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List of all members.

Public Methods

 ACE_WIN32_Asynch_Write_Dgram (ACE_WIN32_Proactor *win32_proactor)
 Constructor. More...

virtual ~ACE_WIN32_Asynch_Write_Dgram (void)
 Destructor. More...

virtual ssize_t send (ACE_Message_Block *message_block, size_t &number_of_bytes_sent, int flags, const ACE_Addr &addr, const void *act, int priority, int signal_number)
int open (ACE_Handler &handler, ACE_HANDLE handle, const void *completion_key, ACE_Proactor *proactor)
int cancel (void)
ACE_Proactor * proactor (void) const
 Return the underlying proactor. More...


Protected Methods

 ACE_WIN32_Asynch_Write_Dgram (void)
 Do-nothing constructor. More...

Detailed Description

This class is a factory for starting off asynchronous writes on a UDP socket.

Once <open> is called, multiple asynchronous <writes>s can started using this class. A ACE_Asynch_Write_Stream::Result will be passed back to the <handler> when the asynchronous write completes through the <ACE_Handler::handle_write_stream> callback.

Definition at line 1876 of file WIN32_Asynch_IO.h.

Constructor & Destructor Documentation

ACE_WIN32_Asynch_Write_Dgram::ACE_WIN32_Asynch_Write_Dgram (  ACE_WIN32_Proactor *    win32_proactor ) 
 

Constructor.

Definition at line 3741 of file WIN32_Asynch_IO.cpp. 

03742   : ACE_Asynch_Operation_Impl (),
03743     ACE_Asynch_Write_Dgram_Impl (),
03744     ACE_WIN32_Asynch_Operation (win32_proactor)
03745 {
03746 }

ACE_WIN32_Asynch_Write_Dgram::~ACE_WIN32_Asynch_Write_Dgram (  void    )  [virtual]
 

Destructor.

Definition at line 3580 of file WIN32_Asynch_IO.cpp. 

03581 {
03582 }

ACE_WIN32_Asynch_Write_Dgram::ACE_WIN32_Asynch_Write_Dgram (  void    )  [protected]
 

Do-nothing constructor.

Member Function Documentation

int ACE_WIN32_Asynch_Write_Dgram::cancel (  void    )  [virtual]
 

This cancels all pending accepts operations that were issued by the calling thread. The function does not cancel asynchronous operations issued by other threads.

Reimplemented from ACE_WIN32_Asynch_Operation.

Definition at line 3730 of file WIN32_Asynch_IO.cpp.

References ACE_WIN32_Asynch_Operation::cancel. 

03731 {
03732   return ACE_WIN32_Asynch_Operation::cancel ();
03733 }

int ACE_WIN32_Asynch_Write_Dgram::open (  ACE_Handler &    handler,
ACE_HANDLE    handle,
const void *    completion_key,
ACE_Proactor *    proactor
)  [virtual]
 

Initializes the factory with information which will be used with each asynchronous call. If (<handle> == ACE_INVALID_HANDLE), <ACE_Handler::handle> will be called on the <handler> to get the correct handle.

Reimplemented from ACE_WIN32_Asynch_Operation.

Definition at line 3718 of file WIN32_Asynch_IO.cpp.

References ACE_WIN32_Asynch_Operation::open. 

03722 {
03723   return ACE_WIN32_Asynch_Operation::open (handler,
03724                                            handle,
03725                                            completion_key,
03726                                            proactor);
03727 }

ACE_Proactor * ACE_WIN32_Asynch_Write_Dgram::proactor (  void    )  const [virtual]
 

Return the underlying proactor.

Reimplemented from ACE_WIN32_Asynch_Operation.

Definition at line 3736 of file WIN32_Asynch_IO.cpp.

References ACE_WIN32_Asynch_Operation::proactor. 

03737 {
03738   return ACE_WIN32_Asynch_Operation::proactor ();
03739 }

ssize_t ACE_WIN32_Asynch_Write_Dgram::send (  ACE_Message_Block *    message_block,
size_t &    number_of_bytes_sent,
int    flags,
const ACE_Addr &    addr,
const void *    act,
int    priority,
int    signal_number
)  [virtual]
 

This starts off an asynchronous send. Upto <message_block->total_length()> will be sent. <message_block>'s <rd_ptr> will be updated to reflect the sent bytes if the send operation is successfully completed. Return code of 1 means immediate success and <number_of_bytes_sent> is updated to number of bytes sent. The <ACE_Handler::handle_write_dgram> method will still be called. Return code of 0 means the IO will complete proactively. Return code of -1 means there was an error, use errno to get the error code.

Scatter/gather is supported on WIN32 by using the <message_block->cont()> method. Up to ACE_IOV_MAX <message_block>'s are supported. Upto <message_block->length()> bytes will be sent from each <message block> for a total of <message_block->total_length()> bytes. All <message_block>'s <rd_ptr>'s will be updated to reflect the bytes sent from each <message_block>.

Implements ACE_Asynch_Write_Dgram_Impl.

Definition at line 3585 of file WIN32_Asynch_IO.cpp.

References ACE_DEBUG, ACE_ERROR_RETURN, ACE_IOV_MAX, ACE_LIB_TEXT, ACE_NEW_RETURN, ACE_Message_Block::cont, ACE::debug, ACE_WIN32_Asynch_Write_Dgram_Result::flags_, ACE_Addr::get_addr, ACE_Addr::get_size, ACE_WIN32_Asynch_Write_Dgram_Result::handle, iovec::iov_base, iovec::iov_len, ACE_Message_Block::length, LM_ERROR, ACE_Message_Block::rd_ptr, ACE_OS::sendto, and ACE_OS::set_errno_to_last_error. 

03592 {
03593   number_of_bytes_sent = 0;
03594 
03595   size_t bytes_to_write = 0;
03596 
03597   iovec  iov[ACE_IOV_MAX];
03598   int    iovcnt = 0;
03599 
03600   for (const ACE_Message_Block* msg = message_block;
03601        msg != 0 && iovcnt < ACE_IOV_MAX;
03602        msg = msg->cont () , ++iovcnt )
03603   {
03604     size_t msg_len = msg->length ();
03605 
03606     // OS should process zero length block correctly
03607     // if ( msg_len == 0 )
03608     //   ACE_ERROR_RETURN ((LM_ERROR,
03609     //                      ACE_LIB_TEXT ("ACE_WIN32_Asynch_Write_Dgram::send:")
03610     //                      ACE_LIB_TEXT ("Zero-length message block\n")),
03611     //                     -1);
03612 
03613     bytes_to_write += msg_len;
03614 
03615     // Make as many iovec as needed to fit all of msg_len.
03616     size_t rd_ptr_offset = 0;
03617     while (msg_len > 0 && iovcnt < ACE_IOV_MAX)
03618       {
03619         u_long this_chunk_length;
03620         if (msg_len > ULONG_MAX)
03621           this_chunk_length = ULONG_MAX;
03622         else
03623           this_chunk_length = ACE_static_cast (u_long, msg_len);
03624         // Collect the data in the iovec.
03625         iov[iovcnt].iov_base = msg->rd_ptr () + rd_ptr_offset;
03626         iov[iovcnt].iov_len  = this_chunk_length;
03627         msg_len -= this_chunk_length;
03628         rd_ptr_offset += this_chunk_length;
03629 
03630         // Increment iovec counter if there's more to do.
03631         if (msg_len > 0)
03632           iovcnt++;
03633       }
03634     if (msg_len > 0)       // Ran out of iovecs before msg_space exhausted
03635       {
03636         errno = ERANGE;
03637         return -1;
03638       }
03639   }
03640 
03641   if ( bytes_to_write == 0 )
03642       ACE_ERROR_RETURN ((LM_ERROR,
03643                          ACE_LIB_TEXT ("ACE_WIN32_Asynch_Write_Dgram::send:")
03644                          ACE_LIB_TEXT ("Attempt to write 0 bytes\n")),
03645                         -1);
03646 
03647   // Create the Asynch_Result.
03648   ACE_WIN32_Asynch_Write_Dgram_Result *result = 0;
03649   ACE_NEW_RETURN (result,
03650                   ACE_WIN32_Asynch_Write_Dgram_Result (*this->handler_,
03651                                                        this->handle_,
03652                                                        message_block,
03653                                                        bytes_to_write,
03654                                                        flags,
03655                                                        act,
03656                                                        this->win32_proactor_->get_handle (),
03657                                                        priority,
03658                                                        signal_number),
03659                   -1);
03660 
03661   // do the scatter/gather send
03662 
03663   int initiate_result = ACE_OS::sendto (result->handle (),
03664                                         iov,
03665                                         iovcnt,
03666                                         number_of_bytes_sent,
03667                                         result->flags_,
03668                                         (sockaddr *) addr.get_addr (),
03669                                         addr.get_size(),
03670                                         result,
03671                                         0);
03672 
03673 
03674   if (initiate_result == SOCKET_ERROR)
03675   {
03676     // If initiate failed, check for a bad error.
03677     ACE_OS::set_errno_to_last_error ();
03678     switch (errno)
03679     {
03680       case ERROR_IO_PENDING:
03681         // The IO will complete proactively: the OVERLAPPED will still
03682         // get queued.
03683         initiate_result = 0;
03684         break;
03685 
03686       default:
03687         // Something else went wrong: the OVERLAPPED will not get
03688         // queued.
03689 
03690         if (ACE::debug ())
03691         {
03692           ACE_DEBUG ((LM_ERROR,
03693                       ACE_LIB_TEXT ("%p\n"),
03694                       ACE_LIB_TEXT ("WSASendTo")));
03695         }
03696 
03697         delete result;
03698         initiate_result = -1;
03699         break;
03700     }
03701 
03702   }
03703   else
03704   {
03705     // Immediate success: the OVERLAPPED will still get queued.
03706     // number_of_bytes_recvd contains the number of bytes recvd
03707     // addr contains the peer address
03708     // flags was updated
03709 
03710     // number_of_bytes_sent = bytes_sent;
03711     initiate_result = 1;
03712   }
03713 
03714   return initiate_result;
03715 }

The documentation for this class was generated from the following files:
Generated on Mon Jun 16 13:00:37 2003 for ACE by doxygen1.2.14 written by Dimitri van Heesch, © 1997-2002