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ACE_Asynch_Read_Dgram Class Reference

This class is a factory for starting off asynchronous reads on a UDP socket. This class forwards all methods to its implementation class. More...

#include <Asynch_IO.h>

Inheritance diagram for ACE_Asynch_Read_Dgram:

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Collaboration diagram for ACE_Asynch_Read_Dgram:

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List of all members.

Public Member Functions

 ACE_Asynch_Read_Dgram (void)
 A do nothing constructor.

virtual ~ACE_Asynch_Read_Dgram (void)
 Destructor.

int open (ACE_Handler &handler, ACE_HANDLE handle=ACE_INVALID_HANDLE, const void *completion_key=0, ACE_Proactor *proactor=0)
ssize_t recv (ACE_Message_Block *message_block, size_t &number_of_bytes_recvd, int flags, int protocol_family=PF_INET, const void *act=0, int priority=0, int signal_number=ACE_SIGRTMIN)
virtual ACE_Asynch_Operation_Impl * implementation (void) const
 Return the underlying implementation class.


Protected Attributes

ACE_Asynch_Read_Dgram_Impl * implementation_
 Implementation class that all methods will be forwarded to.

Detailed Description

This class is a factory for starting off asynchronous reads on a UDP socket. This class forwards all methods to its implementation class.

Once {open} is called, multiple asynchronous {read}s can be started using this class. An ACE_Asynch_Read_Dgram::Result will be passed back to the {handler} when the asynchronous reads completes through the {ACE_Handler::handle_read_dgram} callback.

Definition at line 1258 of file Asynch_IO.h.

Constructor & Destructor Documentation

ACE_Asynch_Read_Dgram::ACE_Asynch_Read_Dgram (  void   ) 
 

A do nothing constructor.

Definition at line 1128 of file Asynch_IO.cpp. 

01129   : implementation_ (0)
01130 {
01131 }

ACE_Asynch_Read_Dgram::~ACE_Asynch_Read_Dgram (  void   )  [virtual]
 

Destructor.

Definition at line 1133 of file Asynch_IO.cpp. 

01134 {
01135   // Delete the implementation.
01136   delete this->implementation_;
01137   this->implementation_ = 0;
01138 }

Member Function Documentation

ACE_Asynch_Operation_Impl * ACE_Asynch_Read_Dgram::implementation (  void   )  const [virtual]
 

Return the underlying implementation class.

Implements ACE_Asynch_Operation.

Definition at line 1179 of file Asynch_IO.cpp. 

01180 {
01181   return this->implementation_;
01182 }

int ACE_Asynch_Read_Dgram::open (  ACE_Handler &  handler,
ACE_HANDLE  handle = ACE_INVALID_HANDLE,
const void *  completion_key = 0,
ACE_Proactor *  proactor = 0
) 
 

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_Asynch_Operation.

Definition at line 1141 of file Asynch_IO.cpp.

References ACE_Proactor::create_asynch_read_dgram(), ACE_Asynch_Operation::get_proactor(), and ACE_Asynch_Operation::open(). 

01145 {
01146   // Get a proactor for/from the user.
01147   proactor = this->get_proactor (proactor, handler);
01148 
01149   // Now let us get the implementation initialized.
01150   if ((this->implementation_ = proactor->create_asynch_read_dgram ()) == 0)
01151     return -1;
01152 
01153   // Call the <open> method of the base class.
01154   return ACE_Asynch_Operation::open (handler,
01155                                      handle,
01156                                      completion_key,
01157                                      proactor);
01158 }

ssize_t ACE_Asynch_Read_Dgram::recv (  ACE_Message_Block *  message_block,
size_t &  number_of_bytes_recvd,
int  flags,
int  protocol_family = PF_INET,
const void *  act = 0,
int  priority = 0,
int  signal_number = ACE_SIGRTMIN
) 
 

This starts off an asynchronous read. Upto {message_block->total_size()} will be read and stored in the {message_block}. {message_block}'s {wr_ptr} will be updated to reflect the added bytes if the read operation is successfully completed. Return code of 1 means immediate success and {number_of_bytes_recvd} will contain number of bytes read. The {ACE_Handler::handle_read_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->size()} bytes will be read into each {message block} for a total of {message_block->total_size()} bytes. All {message_block}'s {wr_ptr}'s will be updated to reflect the added bytes for each {message_block}

Priority of the operation is specified by {priority}. On POSIX4-Unix, this is supported. Works like {nice} in Unix. Negative values are not allowed. 0 means priority of the operation same as the process priority. 1 means priority of the operation is one less than process. And so forth. On Win32, {priority} is a no-op. {signal_number} is the POSIX4 real-time signal number to be used for the operation. {signal_number} ranges from ACE_SIGRTMIN to ACE_SIGRTMAX. This argument is a no-op on non-POSIX4 systems.

Definition at line 1161 of file Asynch_IO.cpp.

References ACE_Asynch_Read_Dgram_Impl::recv(). 

01168 {
01169   return this->implementation_->recv (message_block,
01170                                       number_of_bytes_recvd,
01171                                       flags,
01172                                       protocol_family,
01173                                       act,
01174                                       priority,
01175                                       signal_number);
01176 }

Member Data Documentation

ACE_Asynch_Read_Dgram_Impl* ACE_Asynch_Read_Dgram::implementation_ [protected]
 

Implementation class that all methods will be forwarded to.

Definition at line 1319 of file Asynch_IO.h.

The documentation for this class was generated from the following files:
Generated on Thu Nov 9 11:19:33 2006 for ACE by doxygen 1.3.6