IOBoundAlgSchedulerSvc Class Reference

Please refer to the full documentation of the methods for more details. More...

#include <GaudiHive/src/IOBoundAlgSchedulerSvc.h>

Inheritance diagram for IOBoundAlgSchedulerSvc:

Collaboration diagram for IOBoundAlgSchedulerSvc:

Public Member Functions
	IOBoundAlgSchedulerSvc (const std::string &name, ISvcLocator *svc)
	Constructor. More...
	~IOBoundAlgSchedulerSvc () override
	Destructor. More...
StatusCode	initialize () override
	Initialise. More...
StatusCode	finalize () override
	Finalise. More...
StatusCode	push (IAlgTask &task) override
	Add an algorithm to local queue to run on accelerator. More...
Public Member Functions inherited from extends< BASE, Interfaces >
void *	i_cast (const InterfaceID &tid) const override
	Implementation of IInterface::i_cast. More...
StatusCode	queryInterface (const InterfaceID &ti, void **pp) override
	Implementation of IInterface::queryInterface. More...
std::vector< std::string >	getInterfaceNames () const override
	Implementation of IInterface::getInterfaceNames. More...
	~extends () override=default
	Virtual destructor. More...
Public Member Functions inherited from extend_interfaces< Interfaces... >
	~extend_interfaces () override=default
	Virtual destructor. More...

Private Types
typedef std::function< StatusCode()>	action

Private Member Functions
void	activate ()
	Activate scheduler. More...
StatusCode	deactivate ()
	Deactivate scheduler. More...

Private Attributes
bool	m_isActive
	Flag to track if the scheduler is active or not. More...
std::thread	m_thread
	The thread in which the activate function runs. More...
tbb::concurrent_bounded_queue< action >	m_actionsQueue
	This is done since the copy of the lambda storage is too expensive. More...

Additional Inherited Members
Public Types inherited from extends< BASE, Interfaces >
using	base_class = extends
	Typedef to this class. More...
using	extend_interfaces_base = extend_interfaces< Interfaces... >
	Typedef to the base of this class. More...
Public Types inherited from extend_interfaces< Interfaces... >
using	ext_iids = typename Gaudi::interface_list_cat< typename Interfaces::ext_iids... >::type
	take union of the ext_iids of all Interfaces... More...

Detailed Description

Please refer to the full documentation of the methods for more details.

Author

Illya Shapoval

Version

1.0

Definition at line 25 of file IOBoundAlgSchedulerSvc.h.

Member Typedef Documentation

typedef std::function<StatusCode()> IOBoundAlgSchedulerSvc::action

private

Definition at line 60 of file IOBoundAlgSchedulerSvc.h.

Constructor & Destructor Documentation

IOBoundAlgSchedulerSvc::IOBoundAlgSchedulerSvc	(	const std::string &	name,
		ISvcLocator *	svc
	)

Constructor.

Definition at line 24 of file IOBoundAlgSchedulerSvc.cpp.

    : base_class( name, svcLoc ), m_isActive( false )
{
}

IOBoundAlgSchedulerSvc::~IOBoundAlgSchedulerSvc ( )

override

Destructor.

Definition at line 30 of file IOBoundAlgSchedulerSvc.cpp.

{}

Member Function Documentation

void IOBoundAlgSchedulerSvc::activate ( )

private

Activate scheduler.

Activate the scheduler.

From this moment on the queue of actions is checked. The checking will stop when the m_isActive flag is false and the queue is not empty. This will guarantee that all actions are executed and a stall is not created.

Definition at line 76 of file IOBoundAlgSchedulerSvc.cpp.

{

  // Now it's running
  m_isActive = true;

  // Wait for actions pushed into the queue by finishing tasks.
  action thisAction;
  StatusCode sc( StatusCode::SUCCESS );

  // Continue to wait if the scheduler is running or there is something to do
  info() << "Start checking the queue of I/O-bound algorithm tasks.." << endmsg;
  while ( m_isActive or m_actionsQueue.size() > 0 ) {
    m_actionsQueue.pop( thisAction );
    std::thread th( thisAction );
    th.detach();
  }
}

StatusCode IOBoundAlgSchedulerSvc::deactivate ( )

private

Deactivate scheduler.

Deactivates the scheduler.

Two actions are pushed into the queue: 1) Drain the scheduler until all events are finished. 2) Flip the status flag m_isActive to false This second action is the last one to be executed by the scheduler.

Definition at line 103 of file IOBoundAlgSchedulerSvc.cpp.

{

  if ( m_isActive ) {
    // Drain the scheduler
    // m_actionsQueue.push(std::bind(&IOBoundSchedulerSvc::m_drain,
    //                              this));
    // we set the flag in this thread, not in the last action, to avoid stall,
    // since we execute tasks asynchronously, in a detached thread, and it's possible that
    // the task doesn't complete by the time the last while-iteration is entered
    m_isActive = false;
    // This would be the last (empty) action, just to trigger one last while-iteration
    m_actionsQueue.push( [this]() -> StatusCode { return StatusCode::SUCCESS; } );
  }

  return StatusCode::SUCCESS;
}

StatusCode IOBoundAlgSchedulerSvc::finalize ( )

override

Finalise.

Here the scheduler is deactivated and the thread joined.

Definition at line 55 of file IOBoundAlgSchedulerSvc.cpp.

{

  StatusCode sc( Service::finalize() );
  if ( !sc.isSuccess() ) warning() << "Base class could not be finalized" << endmsg;

  sc = deactivate();
  if ( !sc.isSuccess() ) warning() << "Scheduler could not be deactivated" << endmsg;

  info() << "Joining preemptive scheduler's thread" << endmsg;
  m_thread.join();

  return sc;
}

StatusCode IOBoundAlgSchedulerSvc::initialize ( )

override

Initialise.

Here, among some "bureaucracy" operations, the scheduler is activated, executing the activate() function in a new thread.

Definition at line 37 of file IOBoundAlgSchedulerSvc.cpp.

{

  // Initialise mother class (read properties, ...)
  StatusCode sc( Service::initialize() );
  if ( !sc.isSuccess() ) warning() << "Base class could not be initialized" << endmsg;

  // Activate the scheduler in another thread.
  info() << "Activating scheduler in a separate thread" << endmsg;
  m_thread = std::thread( std::bind( &IOBoundAlgSchedulerSvc::activate, this ) );

  return sc;
}

StatusCode IOBoundAlgSchedulerSvc::push ( IAlgTask &  task )

override

Add an algorithm to local queue to run on accelerator.

Definition at line 121 of file IOBoundAlgSchedulerSvc.cpp.

{

  // the temporary lambda should be moved into the queue in here
  auto actionn = [&]() {
    debug() << " .. launching I/O-bound algo-closure .. " << endmsg;
    return task.execute();
  };

  m_actionsQueue.push( actionn );

  // until the queue to accelerator becomes limited
  return StatusCode::SUCCESS;
}

Member Data Documentation

tbb::concurrent_bounded_queue<action> IOBoundAlgSchedulerSvc::m_actionsQueue

private

This is done since the copy of the lambda storage is too expensive.

Queue where closures are stored and picked for execution

Definition at line 64 of file IOBoundAlgSchedulerSvc.h.

bool IOBoundAlgSchedulerSvc::m_isActive

private

Flag to track if the scheduler is active or not.

Definition at line 53 of file IOBoundAlgSchedulerSvc.h.

std::thread IOBoundAlgSchedulerSvc::m_thread

private

The thread in which the activate function runs.

Definition at line 56 of file IOBoundAlgSchedulerSvc.h.

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

• GaudiHive/src/IOBoundAlgSchedulerSvc.h
• GaudiHive/src/IOBoundAlgSchedulerSvc.cpp