SimTK::ParallelExecutor Class Reference

This class is used for performing multithreaded computations. More...

Inheritance diagram for SimTK::ParallelExecutor:

Classes
class	Task
	Concrete subclasses of this abstract class represent tasks that can be executed by a ParallelExecutor. More...

Public Member Functions
	ParallelExecutor (int numThreads=getNumProcessors())
	Construct a ParallelExecutor. More...
void	execute (Task &task, int times)
	Execute a parallel task. More...
Public Member Functions inherited from SimTK::PIMPLHandle< ParallelExecutor, ParallelExecutorImpl >
bool	isEmptyHandle () const
	Returns true if this handle is empty, that is, does not refer to any implementation object. More...
bool	isOwnerHandle () const
	Returns true if this handle is the owner of the implementation object to which it refers. More...
bool	isSameHandle (const ParallelExecutor &other) const
	Determine whether the supplied handle is the same object as "this" PIMPLHandle. More...
void	disown (ParallelExecutor &newOwner)
	Give up ownership of the implementation to an empty handle. More...
PIMPLHandle &	referenceAssign (const ParallelExecutor &source)
	"Copy" assignment but with shallow (pointer) semantics. More...
PIMPLHandle &	copyAssign (const ParallelExecutor &source)
	This is real copy assignment, with ordinary C++ object ("value") semantics. More...
void	clearHandle ()
	Make this an empty handle, deleting the implementation object if this handle is the owner of it. More...
const ParallelExecutorImpl &	getImpl () const
	Get a const reference to the implementation associated with this Handle. More...
ParallelExecutorImpl &	updImpl ()
	Get a writable reference to the implementation associated with this Handle. More...
int	getImplHandleCount () const
	Return the number of handles the implementation believes are referencing it. More...

Static Public Member Functions
static int	getNumProcessors ()
	Get the number of available processor cores. More...
static bool	isWorkerThread ()
	Determine whether the thread invoking this method is a worker thread created by ParallelExecutor. More...

Additional Inherited Members
Public Types inherited from SimTK::PIMPLHandle< ParallelExecutor, ParallelExecutorImpl >
typedef PIMPLHandle < ParallelExecutor, ParallelExecutorImpl, PTR >	HandleBase
typedef HandleBase	ParentHandle
Protected Member Functions inherited from SimTK::PIMPLHandle< ParallelExecutor, ParallelExecutorImpl >
	PIMPLHandle ()
	The default constructor makes this an empty handle. More...
	PIMPLHandle (ParallelExecutorImpl *p)
	This provides consruction of a handle referencing an existing implementation object. More...
	PIMPLHandle (const PIMPLHandle &source)
	The copy constructor makes either a deep (value) or shallow (reference) copy of the supplied source PIMPL object, based on whether this is a "pointer semantics" (PTR=true) or "object (value) semantics" (PTR=false, default) class. More...
	~PIMPLHandle ()
	Note that the destructor is non-virtual. More...
PIMPLHandle &	operator= (const PIMPLHandle &source)
	Copy assignment makes the current handle either a deep (value) or shallow (reference) copy of the supplied source PIMPL object, based on whether this is a "pointer sematics" (PTR=true) or "object (value) semantics" (PTR=false, default) class. More...
void	setImpl (ParallelExecutorImpl *p)
	Set the implementation for this empty handle. More...
bool	hasSameImplementation (const ParallelExecutor &other) const
	Determine whether the supplied handle is a reference to the same implementation object as is referenced by "this" PIMPLHandle. More...

Detailed Description

This class is used for performing multithreaded computations.

To use it, define a subclass of ParallelExecutor::Task that performs some computation. Then create a ParallelExecutor object and ask it to execute the task:

ParallelExecutor executor;
executor.execute(myTask, times);

The Task's execute() method will be called the specified number of times, with each invocation being given a different index value from 0 to times-1. The invocations are done in parallel on multiple threads, so you cannot make any assumptions about what order they will occur in or which ones will happen at the same time.

The threads are created in the ParallelExecutor's constructor and remain active until it is deleted. This means that creating a ParallelExecutor is a somewhat expensive operation, but it may then be used repeatedly for executing various calculations. By default, the number of threads is chosen to be equal to the number of available processor cores. You can optionally specify a different number of threads to create. For example, using more threads than processors can sometimes lead to better processor utilitization. Alternatively, if the Task will only be executed four times, you might specify min(4, ParallelExecutor::getNumProcessors()) to avoid creating extra threads that will never have any work to do.

Constructor & Destructor Documentation

SimTK::ParallelExecutor::ParallelExecutor ( int  numThreads = getNumProcessors() )

explicit

Construct a ParallelExecutor.

Parameters

numThreads

the number of threads to create. By default, this is set equal to the number of processors.

Member Function Documentation

void SimTK::ParallelExecutor::execute	(	Task &	task,
		int	times
	)

Execute a parallel task.

Parameters

task	the Task to execute
times	the number of times the Task should be executed

static int SimTK::ParallelExecutor::getNumProcessors ( )

static

Get the number of available processor cores.

static bool SimTK::ParallelExecutor::isWorkerThread ( )

static

Determine whether the thread invoking this method is a worker thread created by ParallelExecutor.

---

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

• ParallelExecutor.h