edm::LimitedTaskQueue Class Reference

#include <LimitedTaskQueue.h>

Classes
class	Resumer

Public Member Functions
unsigned int	concurrencyLimit () const
	LimitedTaskQueue (unsigned int iLimit)
template<typename T >
void	push (T &&iAction)
	asynchronously pushes functor iAction into queue More...
template<typename T >
void	pushAndPause (T &&iAction)
	asynchronously pushes functor iAction into queue then pause the queue and run iAction More...
template<typename T >
void	pushAndWait (T &&iAction)
	synchronously pushes functor iAction into queue More...

Private Member Functions
	LimitedTaskQueue (const LimitedTaskQueue &)=delete
const LimitedTaskQueue &	operator= (const LimitedTaskQueue &)=delete

Private Attributes
std::vector< SerialTaskQueue >	m_queues

Detailed Description

Definition at line 38 of file LimitedTaskQueue.h.

Constructor & Destructor Documentation

edm::LimitedTaskQueue::LimitedTaskQueue ( unsigned int  iLimit )

inline

Definition at line 40 of file LimitedTaskQueue.h.

References push(), and pushAndWait().

: m_queues{iLimit} {}

edm::LimitedTaskQueue::LimitedTaskQueue ( const LimitedTaskQueue &  )

privatedelete

Member Function Documentation

unsigned int edm::LimitedTaskQueue::concurrencyLimit ( ) const

inline

Definition at line 115 of file LimitedTaskQueue.h.

References edm::LimitedTaskQueue::Resumer::LimitedTaskQueue, m_queues, and edm::LimitedTaskQueue::Resumer::operator=().

{ return m_queues.size(); }

const LimitedTaskQueue& edm::LimitedTaskQueue::operator= ( const LimitedTaskQueue &  )

privatedelete

template<typename T >

void LimitedTaskQueue::push

(

T &&

iAction

)

asynchronously pushes functor iAction into queue

The function will return immediately and iAction will either process concurrently with the calling thread or wait until the protected resource becomes available or until a CPU becomes available.

Parameters

[in]

iAction

Must be a functor that takes no arguments and return no values.

Definition at line 126 of file LimitedTaskQueue.h.

References m_queues, and lumiQueryAPI::q.

Referenced by LimitedTaskQueue(), and edm::Worker::TaskQueueAdaptor::push().

                                         {
    auto set_to_run = std::make_shared<std::atomic<bool>>(false);
    for (auto& q : m_queues) {
      q.push([set_to_run, iAction]() mutable {
        bool expected = false;
        if (set_to_run->compare_exchange_strong(expected, true)) {
          iAction();
        }
      });
    }
  }

template<typename T >

void LimitedTaskQueue::pushAndPause

(

T &&

iAction

)

asynchronously pushes functor iAction into queue then pause the queue and run iAction

iAction must take as argument a copy of a LimitedTaskQueue::Resumer. To resume the queue let the last copy of the Resumer go out of scope, or call Resumer::resume(). Using this function will decrease the allowed concurrency limit by 1.

Definition at line 160 of file LimitedTaskQueue.h.

References m_queues, lumiQueryAPI::q, and edm::LimitedTaskQueue::Resumer::Resumer().

                                                 {
    auto set_to_run = std::make_shared<std::atomic<bool>>(false);
    for (auto& q : m_queues) {
      q.push([&q, set_to_run, iAction]() mutable {
        bool expected = false;
        if (set_to_run->compare_exchange_strong(expected, true)) {
          q.pause();
          iAction(Resumer(&q));
        }
      });
    }
  }

template<typename T >

void LimitedTaskQueue::pushAndWait

(

T &&

iAction

)

synchronously pushes functor iAction into queue

The function will wait until iAction has completed before returning. If another task is already running on the queue, the system is allowed to find another TBB task to execute while waiting for the iAction to finish. In that way the core is not idled while waiting.

Parameters

[in]

iAction

Must be a functor that takes no arguments and return no values.

Definition at line 139 of file LimitedTaskQueue.h.

References pyrootRender::destroy(), m_queues, and lumiQueryAPI::q.

Referenced by LimitedTaskQueue(), and edm::Worker::TaskQueueAdaptor::pushAndWait().

                                                {
    tbb::empty_task* waitTask = new (tbb::task::allocate_root()) tbb::empty_task;
    waitTask->set_ref_count(2);
    auto set_to_run = std::make_shared<std::atomic<bool>>(false);
    for (auto& q : m_queues) {
      q.push([set_to_run, waitTask, iAction]() mutable {
        bool expected = false;
        if (set_to_run->compare_exchange_strong(expected, true)) {
          try {
            iAction();
          } catch (...) {
          }
          waitTask->decrement_ref_count();
        }
      });
    }
    waitTask->wait_for_all();
    tbb::task::destroy(*waitTask);
  }

Member Data Documentation

std::vector<SerialTaskQueue> edm::LimitedTaskQueue::m_queues

private

Definition at line 122 of file LimitedTaskQueue.h.

Referenced by concurrencyLimit(), push(), pushAndPause(), and pushAndWait().