Standard task that acts as reader or writer at the head of an ACE_Stream. More...

#include <Stream_Modules.h>

Inheritance diagram for ACE_Stream_Head< ACE_SYNCH_DECL >:

Collaboration diagram for ACE_Stream_Head< ACE_SYNCH_DECL >:

Public Member Functions
	ACE_Stream_Head (void)
	Construction.
	~ACE_Stream_Head (void)
	Destruction.
virtual int	open (void *a=0)
virtual int	close (u_long flags=0)
virtual int	put (ACE_Message_Block msg, ACE_Time_Value =0)
virtual int	svc (void)
	Run by a daemon thread to handle deferred processing.
virtual int	init (int argc, ACE_TCHAR *argv[])
	Initializes object when dynamic linking occurs.
virtual int	info (ACE_TCHAR **info_string, size_t length) const
	Returns information on a service object.
virtual int	fini (void)
	Terminates object when dynamic unlinking occurs.
void	dump (void) const
	Dump the state of an object.
Public Attributes
	ACE_ALLOC_HOOK_DECLARE
	Declare the dynamic allocation hooks.
Private Member Functions
int	control (ACE_Message_Block *)
	Performs canonical flushing at the ACE_Stream Head.
int	canonical_flush (ACE_Message_Block *)

Detailed Description

template<ACE_SYNCH_DECL>
class ACE_Stream_Head< ACE_SYNCH_DECL >

Standard task that acts as reader or writer at the head of an ACE_Stream.

A ACE_Message_Block sent to this task (via its put() hook) triggers actions depending on the block type and whether the task is acting as a reader or a writer. If the block is of type ACE_Message_Block::MB_IOCTL, the block's is assumed to contain (beginning at its rd_ptr()) an ACE_IO_Cntl_Msg object and is processed accordingly. This is usually used to set the task's message queue high water and/or low water marks.

When the block is not ACE_Message_Block::MB_IOCTL, processing depends on the ACE_Stream_Head's role in the module:

Reader: If the block is of type ACE_Message_Block::MB_FLUSH, the canonical_flush() method is called. (
See also:
ACE_Stream::canonical_flush().) If the block is any other type, it is queued on this task's message queue. It would thus be available to caller's reading blocks from the containing stream.
Writer: The block is passed to the next module in the stream.

Definition at line 51 of file Stream_Modules.h.

Constructor & Destructor Documentation

template<ACE_SYNCH_DECL >

ACE_Stream_Head< ACE_SYNCH_DECL >::ACE_Stream_Head ( void )

Construction.

Definition at line 19 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::ACE_Stream_Head");
}

template<ACE_SYNCH_DECL >

ACE_Stream_Head< ACE_SYNCH_DECL >::~ACE_Stream_Head ( void )

Destruction.

Definition at line 25 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::~ACE_Stream_Head");
}

Member Function Documentation

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::canonical_flush ( ACE_Message_Block * mb ) [private]

Definition at line 84 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::canonical_flush");
  char *cp = mb->rd_ptr ();

  if (ACE_BIT_ENABLED (*cp, ACE_Task_Flags::ACE_FLUSHR))
    {
      this->flush (ACE_Task_Flags::ACE_FLUSHALL);
      ACE_CLR_BITS (*cp, ACE_Task_Flags::ACE_FLUSHR);
    }

  if (ACE_BIT_ENABLED (*cp, ACE_Task_Flags::ACE_FLUSHW))
    return this->reply (mb);
  else
    mb->release ();
  return 0;
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::close ( u_long flags = 0 ) [virtual]

Hook called from ACE_Thread_Exit when during thread exit and from the default implementation of module_closed(). In general, this method shouldn't be called directly by an application, particularly if the Task is running as an Active Object. Instead, a special message should be passed into the Task via the put() method defined below, and the svc() method should interpret this as a flag to shut down the Task.

Reimplemented from ACE_Task_Base.

Definition at line 48 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::close");
  return 0;
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::control ( ACE_Message_Block * mb ) [private]

Performs canonical flushing at the ACE_Stream Head.

Definition at line 62 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::control");
  ACE_IO_Cntl_Msg *ioc = (ACE_IO_Cntl_Msg *) mb->rd_ptr ();
  ACE_IO_Cntl_Msg::ACE_IO_Cntl_Cmds cmd;

  switch (cmd = ioc->cmd ())
    {
    case ACE_IO_Cntl_Msg::SET_LWM:
    case ACE_IO_Cntl_Msg::SET_HWM:
      this->water_marks (cmd, *(size_t *) mb->cont ()->rd_ptr ());
      ioc->rval (0);
      break;
    default:
      return 0;
    }
  return ioc->rval ();
}

template<ACE_SYNCH_DECL >

void ACE_Stream_Head< ACE_SYNCH_DECL >::dump ( void ) const

Dump the state of an object.

Reimplemented from ACE_Task< ACE_SYNCH_USE >.

Definition at line 31 of file Stream_Modules.cpp.

{
#if defined (ACE_HAS_DUMP)
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::dump");
#endif /* ACE_HAS_DUMP */
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::fini ( void ) [virtual]

Terminates object when dynamic unlinking occurs.

Reimplemented from ACE_Shared_Object.

Definition at line 150 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::fini");
  return 0;
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::info	(	ACE_TCHAR **	info_string,
		size_t	length
	)			const `[virtual]`

Returns information on a service object.

Reimplemented from ACE_Shared_Object.

Definition at line 137 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::info");
  const ACE_TCHAR *name = this->name ();

  if (*strp == 0 && (*strp = ACE_OS::strdup (name)) == 0)
    return -1;
  else
    ACE_OS::strsncpy (*strp, name, length);
  return static_cast<int> (ACE_OS::strlen (name));
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::init	(	int	argc,
		ACE_TCHAR *	argv[]
	)			`[virtual]`

Initializes object when dynamic linking occurs.

Reimplemented from ACE_Shared_Object.

Definition at line 130 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::init");
  return 0;
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::open ( void * args = 0 ) [virtual]

Hook called to initialize a task and prepare it for execution. args can be used to pass arbitrary information into <open>.

Reimplemented from ACE_Task_Base.

Definition at line 41 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::open");
  return 0;
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::put	(	ACE_Message_Block *	,
		ACE_Time_Value *	= `0`
	)			`[virtual]`

A hook method that can be used to pass a message to a task, where it can be processed immediately or queued for subsequent processing in the svc() hook method.

Reimplemented from ACE_Task_Base.

Definition at line 103 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::put");
  int res = 0;

  if (mb->msg_type () == ACE_Message_Block::MB_IOCTL
      && (res = this->control (mb)) == -1)
    return res;

  if (this->is_writer ())
    return this->put_next (mb, tv);
  else // this->is_reader ()
    {
      switch (mb->msg_type ())
        {
        case ACE_Message_Block::MB_FLUSH:
          return this->canonical_flush (mb);
        default:
          break;
        }

      return this->putq (mb, tv);
    }
}

template<ACE_SYNCH_DECL >

int ACE_Stream_Head< ACE_SYNCH_DECL >::svc ( void ) [virtual]

Run by a daemon thread to handle deferred processing.

Reimplemented from ACE_Task_Base.

Definition at line 55 of file Stream_Modules.cpp.

{
  ACE_TRACE ("ACE_Stream_Head<ACE_SYNCH_USE>::svc");
  return -1;
}

Member Data Documentation

template<ACE_SYNCH_DECL >

ACE_Stream_Head< ACE_SYNCH_DECL >::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

Reimplemented from ACE_Task< ACE_SYNCH_USE >.

Definition at line 75 of file Stream_Modules.h.

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

ACE_Stream_Head< ACE_SYNCH_DECL > Class Template Reference

Public Member Functions

Public Attributes

Private Member Functions

Detailed Description

template<ACE_SYNCH_DECL> class ACE_Stream_Head< ACE_SYNCH_DECL >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<ACE_SYNCH_DECL>
class ACE_Stream_Head< ACE_SYNCH_DECL >