exahype2::EnclaveTask Class Reference

Base class for all enclave tasks. More...

#include <EnclaveTask.h>

Inheritance diagram for exahype2::EnclaveTask:

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Public Types
typedef std::function< void()>	Functor

Public Member Functions
	EnclaveTask (int enclaveTaskTypeId, const ::peano4::datamanagement::CellMarker &marker, double t, double dt, double *__restrict__ inputValues, double *__restrict__ outputValues, int numberOfInputValues, int numberOfResultValues, Functor functor)
	Create plain enclave task.
	EnclaveTask (const EnclaveTask &other)=delete
	EnclaveTask (const EnclaveTask &&other)=delete
virtual	~EnclaveTask ()=default
virtual void	run () override
	Computes a task and bookmarks the outcome.
void	computeTask ()
	Compute the task.
int	getTaskId () const
	Return _taskNumber.
Public Member Functions inherited from tarch::multicore::Task
	Task (int taskType, int priority)
	Construct task.
virtual	~Task ()
int	getTaskType () const
int	getPriority () const
void	setPriority (int priority)
	Set priority.
virtual bool	canFuse () const
virtual void	fuse (const std::vector< Task * > &otherTasks, int targetDevice=Host)
	Fuse multiple tasks.
virtual std::string	toString () const

Static Public Member Functions
static int	getNumberOfActiveTasks ()
static void	releaseTaskNumber (int number)
static int	reserveTaskNumber ()
	Reserve a new enclave task number.

Protected Attributes
const int	_taskNumber
	Each task needs a unique number, so we can look up its output.
const ::peano4::datamanagement::CellMarker	_marker
const double	_t
	These are the reconstructed values in the Finite Volume sense and the linear combination in the DG solver.
const double	_dt
double *__restrict__	_inputValues
double *__restrict__	_outputValues
int	_numberOfInputValues
int	_numberOfResultValues
Functor	_functor
double	_maxEigenvalue
Protected Attributes inherited from tarch::multicore::Task
const int	_taskType
int	_priority

Static Protected Attributes
static tarch::logging::Log	_log

Static Private Attributes
static tarch::multicore::TaskEnumerator	_enumerator

Friends
class	EnclaveBookkeeping

Additional Inherited Members
Static Public Attributes inherited from tarch::multicore::Task
static constexpr int	DefaultPriority = 1024
static constexpr int	Host = -1
static constexpr int	DontFuse = -1

Detailed Description

Base class for all enclave tasks.

Please study the enclave task in tandem with the EnclaveBookkeeping. Enclave tasks use the bookkeeping to register themselves (obtain a task number). The bookkeeping thus is aware which enclave tasks are outstanding still. Once an enclave task terminates, it registers itself again with the bookkeeping - this time as finished, so anybody can grab the outcome.

Enclave tasks per se are application-generic. They are given an array of values, they are told how big the output data has to be, and they are also given a functor which tells them what to run on the outcome. They don't know anything about the functor's semantics.

Tasks are automatically destroyed when we make their run() method return false. Enclave tasks however are slightly different: They create their outcome array on the heap. This has to be the CPU heap - not a stack, not an accelerator. When they have computed their stuff, they have to hand over this heap (and the responsibility to destroy it) to the bookkeeping and then can be deleted themselves.

Usage:

Every ExaHyPE solver category defines its own enclave tasks being subclasses of the present, generic type. Enclave tasks are always to be spawned with their task number, so we can efficiently wait for them:

auto newEnclaveTask = new tasks::{{SOLVER_NAME}}EnclaveTask(
  ...
);
 
...
 
tarch::multicore::spawnTask(newEnclaveTask, tarch::multicore::NoInDependencies, newEnclaveTask->getTaskId() );

You should try to release the enclave task numbers eventually. Otherwise, you will get huge enclave task maps and an overflow if you are unlucky.

Data ownership

• The run() operation allocates the output data and then invokes the functor.
• I assume that the functor frees the input data.
• The task allocated the output value within _outputValues itself before it invokes the actual task functor. This happens in computeTask(). We have the following sequence: run() calls computeTask() calls the user's functor. The size of the output field is specified in the constructor argument. The output will be on the heap and is eventually passed over to the enclave bookkeeping. See exahype2::EnclaveBookkeeping::waitForTaskToTerminateAndCopyResultOver().

SmartMPI

If you enable SmartMPI, then all enclave tasks are SmartMPI tasks, too. I could realise this through multiple inheritance, but I have to know excactly how big the memory footprint behind an enclave task is, so I decided against this. Instead, subclasses of the enclave task do specialise w.r.t. SmartMPI.

Definition at line 79 of file EnclaveTask.h.

Member Typedef Documentation

Functor

typedef std::function<void()> exahype2::EnclaveTask::Functor

Definition at line 81 of file EnclaveTask.h.

Constructor & Destructor Documentation

EnclaveTask() [1/3]

exahype2::EnclaveTask::EnclaveTask	(	int	enclaveTaskTypeId,
		const ::peano4::datamanagement::CellMarker &	marker,
		double	t,
		double	dt,
		double *__restrict__	inputValues,
		double *__restrict__	outputValues,
		int	numberOfInputValues,
		int	numberOfResultValues,
		Functor	functor )

Create plain enclave task.

Create an unique id for the task type

It is best to use the parallel factory mechanism within parallel:

static int enclaveTaskTypeId = peano4::parallel::getTaskType("{{SOLVER_INSTANCE}}");

Parameters

inputValues	Has to be created on heap via tarch::multicore::allocateMemory().
enclaveTaskTypeId	Unique id for this type. If you use task merging, only tasks of the same type will be merged.
outputValues	If you pass in nullptr, then the enclave task will create a new array on the heap for the task output and then move this one over into the bookkeeping from where it eventually will be copied once more into the target data field.

See also

_inputValues for a discussion of const qualifiers

Definition at line 30 of file EnclaveTask.cpp.

References _dt, _functor, _inputValues, _marker, _maxEigenvalue, _numberOfInputValues, _numberOfResultValues, _outputValues, _t, _taskNumber, assertion1, tarch::multicore::Task::DefaultPriority, exahype2::EnclaveBookkeeping::getInstance(), logTraceIn, logTraceOut, exahype2::EnclaveBookkeeping::registerTask(), reserveTaskNumber(), tarch::multicore::Task::Task(), and tarch::multicore::Task::toString().

Referenced by EnclaveTask(), and EnclaveTask().

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EnclaveTask() [2/3]

exahype2::EnclaveTask::EnclaveTask ( const EnclaveTask & other )

delete

References EnclaveTask().

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EnclaveTask() [3/3]

exahype2::EnclaveTask::EnclaveTask ( const EnclaveTask && other )

delete

References EnclaveTask().

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~EnclaveTask()

virtual exahype2::EnclaveTask::~EnclaveTask ( )

virtualdefault

Member Function Documentation

computeTask()

void exahype2::EnclaveTask::computeTask

(

)

Compute the task.

Typically invoked by run() - though it might also be called directly by smartMPI, e.g. The routine basically forwards the call to the functor stored within the task. Before that, it checks if the task is supposed to allocate the memory for the task outcomes itself. If so, we allocate in the shared GPU memory, as the task might be deployed there.

Definition at line 69 of file EnclaveTask.cpp.

References _functor, _inputValues, _maxEigenvalue, _numberOfResultValues, _outputValues, _taskNumber, tarch::allocateMemory(), assertion, logDebug, and tarch::ManagedSharedAcceleratorDeviceMemory.

Referenced by run().

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getNumberOfActiveTasks()

int exahype2::EnclaveTask::getNumberOfActiveTasks ( )

static

Definition at line 16 of file EnclaveTask.cpp.

References _enumerator.

Referenced by exahype2::EnclaveBookkeeping::dumpStatistics().

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getTaskId()

int exahype2::EnclaveTask::getTaskId

(

)

const

Return _taskNumber.

Definition at line 85 of file EnclaveTask.cpp.

References _taskNumber.

Referenced by run().

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releaseTaskNumber()

void exahype2::EnclaveTask::releaseTaskNumber ( int number )

static

Definition at line 19 of file EnclaveTask.cpp.

References _enumerator, and logDebug.

Referenced by exahype2::EnclaveBookkeeping::finishedTask(), and exahype2::EnclaveBookkeeping::waitForTaskToTerminateAndReturnResult().

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reserveTaskNumber()

int exahype2::EnclaveTask::reserveTaskNumber ( )

static

Reserve a new enclave task number.

This factory mechanism is implicitly used by the constructor of an enclave task. However, we make it public. Therefore, you can also hijack enclave task numbers. This comes in handy if you want to manually insert predecessor tasks to enclave tasks: You create "your own" enclave task, the enclave task creation will recognise that a task is already associated with a cell, and hence use this one as additional input constraint.

Definition at line 25 of file EnclaveTask.cpp.

References _enumerator.

Referenced by EnclaveTask().

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run()

void exahype2::EnclaveTask::run ( )

overridevirtual

Computes a task and bookmarks the outcome.

Implements tarch::multicore::Task.

Definition at line 61 of file EnclaveTask.cpp.

References _marker, _maxEigenvalue, _numberOfResultValues, _outputValues, computeTask(), exahype2::EnclaveBookkeeping::finishedTask(), exahype2::EnclaveBookkeeping::getInstance(), getTaskId(), logTraceInWith1Argument, and logTraceOut.

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Friends And Related Symbol Documentation

EnclaveBookkeeping

friend class EnclaveBookkeeping

friend

Definition at line 84 of file EnclaveTask.h.

References EnclaveBookkeeping.

Referenced by EnclaveBookkeeping.

Field Documentation

_dt

const double exahype2::EnclaveTask::_dt

protected

Definition at line 101 of file EnclaveTask.h.

Referenced by EnclaveTask().

_enumerator

tarch::multicore::TaskEnumerator exahype2::EnclaveTask::_enumerator

staticprivate

Definition at line 187 of file EnclaveTask.h.

Referenced by getNumberOfActiveTasks(), releaseTaskNumber(), and reserveTaskNumber().

_functor

Functor exahype2::EnclaveTask::_functor

protected

Definition at line 106 of file EnclaveTask.h.

Referenced by computeTask(), and EnclaveTask().

_inputValues

double* __restrict__ exahype2::EnclaveTask::_inputValues

protected

Definition at line 102 of file EnclaveTask.h.

Referenced by computeTask(), and EnclaveTask().

_log

tarch::logging::Log exahype2::EnclaveTask::_log

staticprotected

Definition at line 86 of file EnclaveTask.h.

_marker

const ::peano4::datamanagement::CellMarker exahype2::EnclaveTask::_marker

protected

Definition at line 92 of file EnclaveTask.h.

Referenced by EnclaveTask(), and run().

_maxEigenvalue

double exahype2::EnclaveTask::_maxEigenvalue

protected

Definition at line 107 of file EnclaveTask.h.

Referenced by computeTask(), EnclaveTask(), and run().

_numberOfInputValues

int exahype2::EnclaveTask::_numberOfInputValues

protected

Definition at line 104 of file EnclaveTask.h.

Referenced by EnclaveTask().

_numberOfResultValues

int exahype2::EnclaveTask::_numberOfResultValues

protected

Definition at line 105 of file EnclaveTask.h.

Referenced by computeTask(), EnclaveTask(), and run().

_outputValues

double* __restrict__ exahype2::EnclaveTask::_outputValues

protected

Definition at line 103 of file EnclaveTask.h.

Referenced by computeTask(), EnclaveTask(), and run().

_t

const double exahype2::EnclaveTask::_t

protected

These are the reconstructed values in the Finite Volume sense and the linear combination in the DG solver.

In both cases, the enclave task will free the memory once it has terminated, so the attribute may not be const here.

Definition at line 100 of file EnclaveTask.h.

Referenced by EnclaveTask().

_taskNumber

const int exahype2::EnclaveTask::_taskNumber

protected

Each task needs a unique number, so we can look up its output.

Definition at line 91 of file EnclaveTask.h.

Referenced by computeTask(), EnclaveTask(), and getTaskId().

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

• src/exahype2/EnclaveTask.h
• src/exahype2/EnclaveTask.cpp