dash::Coevent Class Reference

A fortran style coevent. More...

#include <Coevent.h>

Public Types
using	iterator = coarray::CoEventIter
using	const_iterator = coarray::CoEventIter
using	reference = coarray::CoEventRef
using	size_type = int

Public Member Functions
	Coevent (Team &team=dash::Team::All())
	Constructor to setup and initialize an Coevent. More...
iterator	begin () DASH_NOEXCEPT
const_iterator	begin () const DASH_NOEXCEPT
iterator	end ()
const_iterator	end () const
size_type	size () const
void	wait (int count=1)
	wait for a given number of incoming events. More...
int	test ()
void	initialize (Team &team=dash::Team::All())
	initializes the Coevent. More...
Team &	team ()
reference	operator() (const int &unit)
	Operator to select event at given unit. More...
reference	operator() (const team_unit_t &unit)
	Operator to select event at given unit. More...

Detailed Description

A fortran style coevent.

Coevent can be used for point-to-point synchronization. Events can be posted to any image. Waiting on non-local events is not supported.

Note

Coevents might deadlock if multiple units are pinned to the same cpu-core. This is due to progress problems in MPI.

Example:

Coevent events;

events(2).post();
if(this_image() == 2){
 events.wait();
}

Definition at line 45 of file Coevent.h.

Constructor & Destructor Documentation

Coevent()

dash::Coevent::Coevent ( Team &  team = dash::Team::All() )

inlineexplicit

Constructor to setup and initialize an Coevent.

Definition at line 66 of file Coevent.h.

References dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::begin(), dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::end(), initialize(), dash::is_initialized(), and dash::Team::size().

    : _team(&team) {
      if(dash::is_initialized()){
        initialize(team);
      }
    }

Member Function Documentation

initialize()

void dash::Coevent::initialize ( Team &  team = dash::Team::All() )

inline

initializes the Coevent.

If it was already initialized in the Ctor, the second initialization is skipped.

Definition at line 138 of file Coevent.h.

References dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::allocate(), dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::barrier(), dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::begin(), dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::end(), dash::fill(), and dash::Team::size().

Referenced by Coevent().

                                                      {
    if(!_is_initialized){
      _team = &team;
      _event_counts.allocate(_team->size());
      dash::fill(_event_counts.begin(), _event_counts.end(), 0);
      _event_counts.barrier();
      _is_initialized = true;
    }
  }

operator()() [1/2]

reference dash::Coevent::operator() ( const int &  unit )

inline

Operator to select event at given unit.

Definition at line 155 of file Coevent.h.

                                                                     {
    DASH_ASSERT_MSG(dash::is_initialized(), "DASH is not initialized");
    auto ptr = static_cast<pointer>(_event_counts.begin() + unit);
    return reference(ptr);
  }

operator()() [2/2]

reference dash::Coevent::operator() ( const team_unit_t &  unit )

inline

Operator to select event at given unit.

Definition at line 164 of file Coevent.h.

                                                                             {
    return this->operator()(static_cast<int>(unit));
  }

wait()

void dash::Coevent::wait ( int  count = 1 )

inline

wait for a given number of incoming events.

This function is thread-safe

Definition at line 112 of file Coevent.h.

References dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::at(), and dash::Array< ElementType, IndexType, PatternType, LocalMemSpaceT >::begin().

                                  {
    auto gref = _event_counts.at(_team->myid().id);
    int current;
    do {
#ifdef DASH_DEBUG
      // avoid spamming the logs while busy waiting
      DASH_LOG_DEBUG("waiting for event at gptr",
                     static_cast<pointer>(_event_counts.begin()
                                         +_team->myid().id));
      std::this_thread::sleep_for(std::chrono::milliseconds(100));
#endif
      current = gref.get();
    } while (current < count);
    // decrement the counter
    gref.sub(count);
  }

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

• /tmp/tmporruphar/dash/include/dash/Coevent.h