exahype2::EnclaveBookkeeping Class Reference

Enclave bookkeeping. More...

#include <EnclaveBookkeeping.h>

Collaboration diagram for exahype2::EnclaveBookkeeping:

Data Structures
struct	Entry

Public Member Functions
void	dumpStatistics ()
	For debugging only.
void	waitForTaskToTerminateAndCopyResultOver (int number, double *destination, double &maxEigenvalue)
	Wait for a task and copy outcome into destination.
void	waitForTaskAndDiscardResult (int number)
	Wait for a task and copy outcome into destination.
void	cancelTask (int number)
void	finishedTask (int taskNumber, int numberOfResultValues, double *data, double maxEigenvalue)
	Usually called directly by EnclaveTask.

Static Public Member Functions
static EnclaveBookkeeping &	getInstance ()

Static Public Attributes
static constexpr int	NoEnclaveTaskNumber = -1
static constexpr int	SkeletonTask = -2
	Skeletons are not really tasks in the traditional sense.

Private Member Functions
	EnclaveBookkeeping ()=default
Entry	waitForTaskToTerminateAndReturnResult (int number)
	Wait for a task result to become available.

Private Attributes
std::unordered_map< int, Entry >	_finishedTasks
	Plain map onto ouput array.
std::set< int >	_tasksThatHaveToBeCancelled
tarch::multicore::BooleanSemaphore	_finishedTasksSemaphore

Static Private Attributes
static tarch::logging::Log	_log
static const std::string	MemoryAllocationsInLookupTableIdentifier

Detailed Description

Enclave bookkeeping.

The enclave bookkeeping is basically a big map which stores results of enclave tasks. Most of the documentation around enclave tasks can be found in exahype2::EnclaveTask.

The bookkeeping can be used in two ways by the underlying enclave task object: The enclave tasks can allocate data for their results on the heap, hand that heap object over to the bookkeeping, and the bookkeeping then hands out the results to the actual solver by copying it into the right place in the mesh and subsequently freeing the tasks's output.

Alternatively, we can work directly on the heap, i.e. the mesh tells us where the result should end up. In our tests, it is not always clear which variant is faster. Which is kind of a surprise. Likely it has to do with memory/cache issues.

Definition at line 39 of file EnclaveBookkeeping.h.

Constructor & Destructor Documentation

EnclaveBookkeeping()

exahype2::EnclaveBookkeeping::EnclaveBookkeeping ( )

privatedefault

Member Function Documentation

cancelTask()

void exahype2::EnclaveBookkeeping::cancelTask

(

int

number

)

Definition at line 40 of file EnclaveBookkeeping.cpp.

References exahype2::EnclaveBookkeeping::Entry::data, tarch::freeMemory(), tarch::ManagedSharedAcceleratorDeviceMemory, and exahype2::EnclaveTask::releaseTaskNumber().

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dumpStatistics()

void exahype2::EnclaveBookkeeping::dumpStatistics

(

)

For debugging only.

This routine is not thread-safe.

Definition at line 27 of file EnclaveBookkeeping.cpp.

References exahype2::EnclaveTask::getNumberOfActiveTasks(), and logInfo.

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finishedTask()

void exahype2::EnclaveBookkeeping::finishedTask	(	int	taskNumber,
		int	numberOfResultValues,
		double *	data,
		double	maxEigenvalue )

Usually called directly by EnclaveTask.

Once this routine is called, the ownership of data passes over into the enclave bookkeeping. Basically, the enclave bookkeepting stores the passed pointer into a map and returns.

There is one exception to this: If we use optimistic time stepping, then we might run into a situation where a task overwrites a previous result. At the moment, this variant yields a warning, but in any case, the old data is first released, before we store the new pointer.

Parameters

data	Has to be device memory allocated through tarch::multicore::allocateMemory()

Definition at line 102 of file EnclaveBookkeeping.cpp.

References assertionEquals1, tarch::multicore::Lock::free(), tarch::logging::Statistics::getInstance(), tarch::logging::Statistics::inc(), logDebug, logWarning, and exahype2::EnclaveTask::releaseTaskNumber().

Referenced by exahype2::EnclaveTask::run().

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getInstance()

exahype2::EnclaveBookkeeping & exahype2::EnclaveBookkeeping::getInstance ( )

static

Definition at line 21 of file EnclaveBookkeeping.cpp.

Referenced by exahype2::EnclaveTask::run().

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waitForTaskAndDiscardResult()

void exahype2::EnclaveBookkeeping::waitForTaskAndDiscardResult

(

int

number

)

Wait for a task and copy outcome into destination.

Definition at line 69 of file EnclaveBookkeeping.cpp.

References exahype2::EnclaveBookkeeping::Entry::data, tarch::freeMemory(), logTraceInWith1Argument, logTraceOut, and tarch::ManagedSharedAcceleratorDeviceMemory.

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waitForTaskToTerminateAndCopyResultOver()

void exahype2::EnclaveBookkeeping::waitForTaskToTerminateAndCopyResultOver	(	int	number,
		double *	destination,
		double &	maxEigenvalue )

Wait for a task and copy outcome into destination.

We use waitForTaskToTerminateAndReturnResult() to obtain a handle to the task outcome. Once we get it, we have to check what to do next:

If an enclave task had been given the memory location where to dump the result directly, we simply return. In this case, the task outcome pointer and destination point to the same address.

If the task had allocated its own output data area on the heap, we copy the content from there into destination and then delete the task's memory location via

tarch::freeMemory( result, tarch::MemoryLocation::ManagedSharedAcceleratorDeviceMemory );

Definition at line 79 of file EnclaveBookkeeping.cpp.

References exahype2::EnclaveBookkeeping::Entry::data, tarch::freeMemory(), logDebug, logTraceInWith1Argument, logTraceOutWith2Arguments, tarch::ManagedSharedAcceleratorDeviceMemory, exahype2::EnclaveBookkeeping::Entry::maxEigenvalue, exahype2::EnclaveBookkeeping::Entry::numberOfResultValues, and exahype2::EnclaveBookkeeping::Entry::toString().

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waitForTaskToTerminateAndReturnResult()

exahype2::EnclaveBookkeeping::Entry exahype2::EnclaveBookkeeping::waitForTaskToTerminateAndReturnResult ( int number )

private

Wait for a task result to become available.

We wait for the task to terminate, and then return the meta object which describes the task properties.

Returns

Entry with all meta data plus a pointer to the actual task result.

Definition at line 54 of file EnclaveBookkeeping.cpp.

References assertionEquals, tarch::multicore::Lock::free(), exahype2::EnclaveTask::releaseTaskNumber(), and tarch::multicore::waitForTask().

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Field Documentation

_finishedTasks

std::unordered_map<int, Entry > exahype2::EnclaveBookkeeping::_finishedTasks

private

Plain map onto ouput array.

See lifecycle discussion of EnclaveTask for details.

Definition at line 58 of file EnclaveBookkeeping.h.

_finishedTasksSemaphore

tarch::multicore::BooleanSemaphore exahype2::EnclaveBookkeeping::_finishedTasksSemaphore

private

Definition at line 62 of file EnclaveBookkeeping.h.

_log

tarch::logging::Log exahype2::EnclaveBookkeeping::_log

staticprivate

Definition at line 50 of file EnclaveBookkeeping.h.

_tasksThatHaveToBeCancelled

std::set<int> exahype2::EnclaveBookkeeping::_tasksThatHaveToBeCancelled

private

Definition at line 60 of file EnclaveBookkeeping.h.

MemoryAllocationsInLookupTableIdentifier

const std::string exahype2::EnclaveBookkeeping::MemoryAllocationsInLookupTableIdentifier

staticprivate

Definition at line 52 of file EnclaveBookkeeping.h.

NoEnclaveTaskNumber

constexpr int exahype2::EnclaveBookkeeping::NoEnclaveTaskNumber = -1

staticconstexpr

Definition at line 77 of file EnclaveBookkeeping.h.

SkeletonTask

constexpr int exahype2::EnclaveBookkeeping::SkeletonTask = -2

staticconstexpr

Skeletons are not really tasks in the traditional sense.

But we can see them as tasks which are immediately ran.

Definition at line 82 of file EnclaveBookkeeping.h.

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

• src/exahype2/EnclaveBookkeeping.h
• src/exahype2/EnclaveBookkeeping.cpp