OpenDDS::DCPS::ThreadPerConnectionSendTask Class Reference

Execute the requests of sending a sample or control message. More...

#include <ThreadPerConnectionSendTask.h>

Inheritance diagram for OpenDDS::DCPS::ThreadPerConnectionSendTask:

[legend]Collaboration diagram for OpenDDS::DCPS::ThreadPerConnectionSendTask:

[legend]List of all members.

Public Member Functions
	ThreadPerConnectionSendTask (DataLink *link)
	Constructor.
virtual	~ThreadPerConnectionSendTask ()
	Virtual Destructor.
int	add_request (SendStrategyOpType op, TransportQueueElement *element=0)
virtual int	open (void *=0)
	Activate the worker threads.
virtual int	svc ()
	The "mainline" executed by the worker thread.
virtual int	close (u_long flag=0)
	Called when the thread exits.
RemoveResult	remove_sample (const DataSampleElement *element)
	Remove sample from the thread per connection queue.
Private Types
typedef ACE_SYNCH_MUTEX	LockType
typedef ACE_Guard< LockType >	GuardType
typedef ACE_Condition< LockType >	ConditionType
typedef BasicQueue< SendRequest >	QueueType
Private Member Functions
virtual void	execute (SendRequest &req)
	Handle the request.
Private Attributes
LockType	lock_
	Lock to protect the "state" (all of the data members) of this object.
QueueType	queue_
	The request queue.
ConditionType	work_available_
bool	shutdown_initiated_
	Flag used to initiate a shutdown request to all worker threads.
bool	opened_
	Flag used to avoid multiple open() calls.
ACE_thread_t	thr_id_
	The id of the thread created by this task.
DataLink *	link_
	The datalink to send the samples or control messages.

---

Detailed Description

Execute the requests of sending a sample or control message.

This task implements the request execute method which handles each step of sending a sample or control message.

Definition at line 55 of file ThreadPerConnectionSendTask.h.

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Member Typedef Documentation

typedef ACE_Condition<LockType> OpenDDS::DCPS::ThreadPerConnectionSendTask::ConditionType [private]

Definition at line 88 of file ThreadPerConnectionSendTask.h.

typedef ACE_Guard<LockType> OpenDDS::DCPS::ThreadPerConnectionSendTask::GuardType [private]

Definition at line 87 of file ThreadPerConnectionSendTask.h.

typedef ACE_SYNCH_MUTEX OpenDDS::DCPS::ThreadPerConnectionSendTask::LockType [private]

Definition at line 86 of file ThreadPerConnectionSendTask.h.

typedef BasicQueue<SendRequest> OpenDDS::DCPS::ThreadPerConnectionSendTask::QueueType [private]

Definition at line 90 of file ThreadPerConnectionSendTask.h.

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Constructor & Destructor Documentation

OpenDDS::DCPS::ThreadPerConnectionSendTask::ThreadPerConnectionSendTask

(

DataLink *

link

)

Constructor.

Definition at line 24 of file ThreadPerConnectionSendTask.cpp.

References DBG_ENTRY_LVL.

  : lock_()
  , queue_(1, 10)
  , work_available_(lock_)
  , shutdown_initiated_(false)
  , opened_(false)
  , thr_id_(ACE_OS::NULL_thread)
  , link_(link)
{
  DBG_ENTRY_LVL("ThreadPerConnectionSendTask", "ThreadPerConnectionSendTask", 6);
}

OpenDDS::DCPS::ThreadPerConnectionSendTask::~ThreadPerConnectionSendTask

(

)

[virtual]

Virtual Destructor.

Definition at line 36 of file ThreadPerConnectionSendTask.cpp.

References DBG_ENTRY_LVL.

{
  DBG_ENTRY_LVL("ThreadPerConnectionSendTask", "~ThreadPerConnectionSendTask", 6);
}

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Member Function Documentation

int OpenDDS::DCPS::ThreadPerConnectionSendTask::add_request	(	SendStrategyOpType	op,
		TransportQueueElement *	element = 0
	)

Put the request to the request queue. Returns 0 if successful, -1 otherwise (it has been "rejected" or this task is shutdown).

Definition at line 41 of file ThreadPerConnectionSendTask.cpp.

References DBG_ENTRY, OpenDDS::DCPS::BasicQueue< T >::put(), queue_, and work_available_.

Referenced by OpenDDS::DCPS::DataLink::send(), OpenDDS::DCPS::DataLink::send_start(), and OpenDDS::DCPS::DataLink::send_stop().

{
  DBG_ENTRY("ThreadPerConnectionSendTask", "add");

  ACE_Auto_Ptr<SendRequest> req(new SendRequest);
  req->op_ = op;
  req->element_ = element;

  int result = -1;
  { // guard scope
    GuardType guard(this->lock_);

    if (this->shutdown_initiated_) {
      return -1;
    }

    result = this->queue_.put(req.get());

    if (result == 0) {
      this->work_available_.signal();
      req.release();

    } else {
      ACE_ERROR((LM_ERROR,
                 ACE_TEXT("(%P|%t) ERROR: ThreadPerConnectionSendTask::add %p\n"),
                 ACE_TEXT("put")));
    }
  }

  return result;
}

int OpenDDS::DCPS::ThreadPerConnectionSendTask::close

(

u_long

flag = 0

)

[virtual]

Called when the thread exits.

Definition at line 174 of file ThreadPerConnectionSendTask.cpp.

References DBG_ENTRY, shutdown_initiated_, and work_available_.

Referenced by OpenDDS::DCPS::DataLink::pre_stop_i(), and OpenDDS::DCPS::DataLink::~DataLink().

{
  DBG_ENTRY("ThreadPerConnectionSendTask","close");

  if (flag == 0) {
    return 0;
  }

  {
    GuardType guard(this->lock_);

    if (this->shutdown_initiated_) {
      return 0;
    }

    // Set the shutdown flag to true.
    this->shutdown_initiated_ = true;
    this->work_available_.signal();
  }

  if (this->opened_ && !ACE_OS::thr_equal(this->thr_id_, ACE_OS::thr_self())) {
    this->wait();
  }

  return 0;
}

void OpenDDS::DCPS::ThreadPerConnectionSendTask::execute

(

SendRequest &

req

)

[private, virtual]

Handle the request.

Definition at line 216 of file ThreadPerConnectionSendTask.cpp.

References DBG_ENTRY_LVL, OpenDDS::DCPS::SendRequest::element_, OpenDDS::DCPS::GUID_UNKNOWN, link_, OpenDDS::DCPS::SendRequest::op_, OpenDDS::DCPS::SEND, OpenDDS::DCPS::DataLink::send_i(), OpenDDS::DCPS::SEND_START, OpenDDS::DCPS::DataLink::send_start_i(), OpenDDS::DCPS::SEND_STOP, and OpenDDS::DCPS::DataLink::send_stop_i().

Referenced by svc().

{
  DBG_ENTRY_LVL("ThreadPerConnectionSendTask", "execute", 6);



  switch (req.op_) {
  case SEND_START:
    this->link_->send_start_i();
    break;
  case SEND:
    this->link_->send_i(req.element_);
    break;
  case SEND_STOP:
    //DataLink::send_stop_i expects the RepoId of the message sender, however, in ThreadPerConnectionSendTask
    //the control element will be a null element with only the op_ set.  Thus pass in GUID_UNKNOWN which will
    //allow send_stop to call send_delayed_notifications without a match.  In the case of ThreadPerConnectionSendTask
    //this is allowable because only one thread will be managing the sending thus no deadlock down in send_delayed_notifications()
    this->link_->send_stop_i(GUID_UNKNOWN);
    break;
  default:
    ACE_ERROR((LM_ERROR, "(%P|%t) ERROR: ThreadPerConnectionSendTask::execute unknown command %d\n",
               req.op_));
    break;
  }
}

int OpenDDS::DCPS::ThreadPerConnectionSendTask::open

(

void *

= 0

)

[virtual]

Activate the worker threads.

Definition at line 74 of file ThreadPerConnectionSendTask.cpp.

References DBG_ENTRY, OpenDDS::DCPS::DCPS_debug_level, opened_, and TheServiceParticipant.

{
  DBG_ENTRY("ThreadPerConnectionSendTask", "open");

  GuardType guard(this->lock_);

  // We can assume that we are in the proper state to handle this open()
  // call as long as we haven't been open()'ed before.
  if (this->opened_) {
    ACE_ERROR_RETURN((LM_ERROR,
                      "(%P|%t) ThreadPerConnectionSendTask failed to open.  "
                      "Task has previously been open()'ed.\n"),
                     -1);
  }

  DirectPriorityMapper mapper(this->link_->transport_priority());
  int priority = mapper.thread_priority();

  long flags  = THR_NEW_LWP | THR_JOINABLE ;//|THR_SCOPE_PROCESS | THR_SCOPE_THREAD;
  int policy = TheServiceParticipant->scheduler();

  if (policy >= 0) {
    flags |= policy;
  } else {
    flags |= THR_INHERIT_SCHED;
  }

  if (DCPS_debug_level > 0) {
    ACE_DEBUG((LM_DEBUG,
               ACE_TEXT("(%P|%t) ThreadPerConnectionSendTask::open(): ")
               ACE_TEXT("activating thread with flags 0x%08.8x ")
               ACE_TEXT("and priority %d.\n"),
               flags,
               priority));
  }

  // Activate this task object with one worker thread.
  if (this->activate(flags, 1, 0, priority) != 0) {
    // Assumes that when activate returns non-zero return code that
    // no threads were activated.
    ACE_ERROR_RETURN((LM_ERROR,
                      "(%P|%t) ThreadPerConnectionSendTask failed to activate "
                      "the worker threads.\n"),
                     -1);
  }

  // Now we have past the point where we can say we've been open()'ed before.
  this->opened_ = true;

  return 0;
}

RemoveResult OpenDDS::DCPS::ThreadPerConnectionSendTask::remove_sample

(

const DataSampleElement *

element

)

Remove sample from the thread per connection queue.

Definition at line 202 of file ThreadPerConnectionSendTask.cpp.

References OpenDDS::DCPS::BasicQueue< T >::accept_visitor(), DBG_ENTRY, OpenDDS::DCPS::DataSampleElement::get_sample(), queue_, and OpenDDS::DCPS::ThreadPerConRemoveVisitor::status().

Referenced by OpenDDS::DCPS::DataLink::remove_sample().

{
  DBG_ENTRY("ThreadPerConnectionSendTask", "remove_sample");

  GuardType guard(this->lock_);

  ACE_Message_Block* payload = element->get_sample()->cont();
  ThreadPerConRemoveVisitor visitor(payload);

  this->queue_.accept_visitor(visitor);

  return visitor.status();
}

int OpenDDS::DCPS::ThreadPerConnectionSendTask::svc

(

)

[virtual]

The "mainline" executed by the worker thread.

Definition at line 126 of file ThreadPerConnectionSendTask.cpp.

References DBG_ENTRY_LVL, execute(), OpenDDS::DCPS::BasicQueue< T >::get(), queue_, and thr_id_.

{
  DBG_ENTRY_LVL("ThreadPerConnectionSendTask", "svc", 6);

  this->thr_id_ = ACE_OS::thr_self();

  // Ignore all signals to avoid
  //     ERROR: <something descriptive> Interrupted system call
  // The main thread will handle signals.
  sigset_t set;
  ACE_OS::sigfillset(&set);
  ACE_OS::thr_sigsetmask(SIG_SETMASK, &set, NULL);

  // Start the "GetWork-And-PerformWork" loop for the current worker thread.
  while (!this->shutdown_initiated_) {
    SendRequest* req;
    {
      GuardType guard(this->lock_);

      if (this->queue_.size() == 0) {
        this->work_available_.wait();
      }

      if (this->shutdown_initiated_) {
        break;
      }

      req = queue_.get();

      if (req == 0) {
        //I'm not sure why this thread got more signals than actual signals
        //when using thread_per_connection and the user application thread
        //send requests without interval. We just need ignore the dequeue
        //failure.
        //ACE_ERROR ((LM_ERROR, "(%P|%t) ERROR: ThreadPerConnectionSendTask::svc  %p\n",
        //  ACE_TEXT("dequeue_head")));
        continue;
      }
    }

    this->execute(*req);
    delete req;
  }

  // This will never get executed.
  return 0;
}

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Member Data Documentation

DataLink* OpenDDS::DCPS::ThreadPerConnectionSendTask::link_ [private]

The datalink to send the samples or control messages.

Definition at line 114 of file ThreadPerConnectionSendTask.h.

Referenced by execute().

LockType OpenDDS::DCPS::ThreadPerConnectionSendTask::lock_ [private]

Lock to protect the "state" (all of the data members) of this object.

Definition at line 93 of file ThreadPerConnectionSendTask.h.

bool OpenDDS::DCPS::ThreadPerConnectionSendTask::opened_ [private]

Flag used to avoid multiple open() calls.

Definition at line 108 of file ThreadPerConnectionSendTask.h.

Referenced by open().

QueueType OpenDDS::DCPS::ThreadPerConnectionSendTask::queue_ [private]

The request queue.

Definition at line 96 of file ThreadPerConnectionSendTask.h.

Referenced by add_request(), remove_sample(), and svc().

bool OpenDDS::DCPS::ThreadPerConnectionSendTask::shutdown_initiated_ [private]

Flag used to initiate a shutdown request to all worker threads.

Definition at line 105 of file ThreadPerConnectionSendTask.h.

Referenced by close().

ACE_thread_t OpenDDS::DCPS::ThreadPerConnectionSendTask::thr_id_ [private]

The id of the thread created by this task.

Definition at line 111 of file ThreadPerConnectionSendTask.h.

Referenced by svc().

ConditionType OpenDDS::DCPS::ThreadPerConnectionSendTask::work_available_ [private]

Condition used to signal the worker threads that they may be able to find a request in the queue_ that needs to be executed. This condition will be signal()'ed each time a request is added to the queue_, and also when this task is shutdown.

Definition at line 102 of file ThreadPerConnectionSendTask.h.

Referenced by add_request(), and close().

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

• ThreadPerConnectionSendTask.h
• ThreadPerConnectionSendTask.cpp

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