Handle class for functor-based threaded runnable objects. More...

#include <rw/thread/RWTThreadIOUFunction.h>

Inheritance diagram for RWTThreadIOUFunction< Return >:

Public Member Functions
	RWTThreadIOUFunction ()

	RWTThreadIOUFunction (const RWTThreadIOUFunction< Return > &second)

	~RWTThreadIOUFunction ()

RWTFunctor< Return()>	getFunctor () const

RWTIOUResult< Return >	operator() () const

RWTThreadIOUFunction< Return > &	operator= (const RWTThreadIOUFunction< Return > &second)

RWTIOUResult< Return >	result () const

void	setFunctor (const RWTFunctor< Return()> &functor)

void	setIOUEscrow (const RWTIOUEscrow< Return > &escrow)

Public Member Functions inherited from RWThread
	RWThread ()

	RWThread (RWStaticCtor)

	RWThread (const RWThread &second)

	~RWThread ()

bool	canGetPriority () const

bool	canGetProcessScopePriority () const

bool	canGetSchedulingPolicy () const

bool	canGetSystemScopePriority () const

bool	canGetTimeSliceQuantum () const

bool	canSetPriority () const

bool	canSetProcessScopePriority () const

bool	canSetSchedulingPolicy (RWSchedulingPolicy policy) const

bool	canSetSystemScopePriority () const

bool	canSetTimeSliceQuantum () const

RWThreadAttribute	getActiveAttribute () const

RWThreadAttribute	getAttribute () const

RWPriority	getMaxPriority () const

RWPriority	getMaxProcessScopePriority () const

RWPriority	getMaxSystemScopePriority () const

unsigned long	getMaxTimeSliceQuantum () const

RWPriority	getMinPriority () const

RWPriority	getMinProcessScopePriority () const

RWPriority	getMinSystemScopePriority () const

unsigned long	getMinTimeSliceQuantum () const

RWPriority	getPriority () const

RWPriority	getProcessScopePriority () const

RWThreadSelf	getRWThreadSelf () const

RWSchedulingPolicy	getSchedulingPolicy () const

unsigned	getSuspendCount () const

RWPriority	getSystemScopePriority () const

unsigned long	getTimeSliceQuantum () const

RWThread &	operator= (const RWThread &second)

unsigned	resume ()

void	setAttribute (const RWThreadAttribute &second)

void	setPriority (RWPriority priority)

void	setProcessScopePriority (RWPriority priority)

void	setSchedulingPolicy (RWSchedulingPolicy policy)

void	setSystemScopePriority (RWPriority priority)

void	setTimeSliceQuantum (unsigned long milliseconds)

unsigned	suspend ()

void	terminate ()

Public Member Functions inherited from RWRunnable
	RWRunnable ()

	RWRunnable (RWStaticCtor)

	RWRunnable (const RWRunnable &second)

	~RWRunnable ()

RWRunnable	getNestedRunnable () const

RWRunnableSelf	getRWRunnableSelf () const

void	join (void)

RWWaitStatus	join (unsigned long milliseconds)

RWRunnable &	operator= (const RWRunnable &second)

void	raise () const

void	releaseInterrupt ()

RWWaitStatus	requestCancellation ()

RWWaitStatus	requestCancellation (unsigned long milliseconds)

RWWaitStatus	requestInterrupt ()

RWWaitStatus	requestInterrupt (unsigned long milliseconds)

RWCompletionState	start ()

RWExecutionState	wait (unsigned long stateMask)

RWWaitStatus	wait (unsigned long stateMask, RWExecutionState *state, unsigned long milliseconds)

Public Member Functions inherited from RWRunnableHandle
void	addCallback (const RWTFunctor< void(const RWRunnable &, RWExecutionState)> &functor, unsigned long stateMask, RWCallbackScope scope=RW_CALL_REPEATEDLY)

RWCompletionState	getCompletionState () const

RWExecutionState	getExecutionState () const

bool	isInterruptRequested () const

bool	isSelf () const

bool	isSelf (const RWThreadId &id) const

void	removeCallback (const RWTFunctor< void(const RWRunnable &, RWExecutionState)> &functor)

RWThreadId	threadId () const

Public Member Functions inherited from RWHandleBase
bool	isValid (void) const

bool	operator!= (const RWHandleBase &second) const

bool	operator< (const RWHandleBase &second) const

bool	operator== (const RWHandleBase &second) const

Static Public Member Functions
static RWTThreadIOUFunction< Return >	make ()

static RWTThreadIOUFunction< Return >	make (const RWTFunctor< Return()> &functor)

static RWTThreadIOUFunction< Return >	make (const RWTIOUEscrow< Return > &escrow, const RWTFunctor< Return()> &functor)

static RWTThreadIOUFunction< Return >	make (const RWTFunctor< Return()> &functor, const RWThreadAttribute &attr)

static RWTThreadIOUFunction< Return >	make (const RWTIOUEscrow< Return > &escrow, const RWTFunctor< Return()> &functor, const RWThreadAttribute &attr)

Static Public Member Functions inherited from RWThread
static bool	canGetMaxThreads ()

static bool	canSuspendResume ()

static size_t	getMaxThreads ()

Additional Inherited Members
Protected Member Functions inherited from RWThread
	RWThread (RWThreadImp *threadImpP)

Protected Member Functions inherited from RWRunnable
	RWRunnable (const RWRunnableSelf &second)

Protected Member Functions inherited from RWRunnableHandle
	RWRunnableHandle ()

	RWRunnableHandle (RWStaticCtor)

	RWRunnableHandle (RWRunnableImp *runnableImpP)

	RWRunnableHandle (const RWRunnableHandle &second)

	~RWRunnableHandle ()

RWRunnableHandle &	operator= (const RWRunnableHandle &second)

Protected Member Functions inherited from RWHandleBase
	RWHandleBase (void)

	RWHandleBase (RWStaticCtor)

	RWHandleBase (RWBodyBase *body)

	RWHandleBase (const RWHandleBase &second)

	~RWHandleBase (void)

RWBodyBase &	body (void) const

RWHandleBase &	operator= (const RWHandleBase &second)

Detailed Description

template<class Return>
class RWTThreadIOUFunction< Return >

The RWTThreadIOUFunction class is a handle class for functor-based threaded runnable objects.

A runnable object provides the basic mechanisms used to create, control, and monitor the threads of execution within your application. Runnables are used to define the task or activity to be performed by a thread.

Each runnable object is reference-counted. A threaded runnable body instance keeps a count of the number of handles that currently reference it. A runnable object is deleted when the last handle that references the body is deleted.

A functor-based runnable accepts a functor object for execution. A functor is an object used to encapsulate a function call. Each functor keeps a pointer to the function and copies of the argument values that are to be passed to the function. Invoking a functor produces a call to the function, and in this case, a return value.

A functor-based runnable simply redefines the basic run() member to invoke a functor instance stored within the runnable. With this capability, you do not have to resort to sub-classing or other intrusive techniques to customize the execution behavior of a runnable. The functor-based runnables allow you to dynamically specify the functions you want to execute when a runnable is started.

RWTThreadIOUFunction is used to access a threaded runnable, which creates a new thread to execute the specified functor. The result of the functor is returned in the form of an IOU. An IOU may be obtained as soon as the runnable is created. To get the actual result from the IOU you must redeem it. If the result has not yet been calculated, the calling thread blocks until it has.

Example: #include <iostream>

#include <math.h>

#include <rw/functor/rwBind.h>

#include <rw/itc/RWTIOUResult.h>

#include <rw/thread/RWTThreadIOUFunction.h>

int greatestPrime(int limit)

{

// The sieve of Eratosthenes:

int i, m;

char* sieve = new char[limit + 1];

if (sieve == 0) {

return -1; // not enough memory

}

for (i = 0; i <= limit; ++i) {

sieve[i] = 1;

}

for (i = 2; i <= sqrt((double)limit); ++i) {

if (sieve[i] != 0) {

for (m = i + i; m <= limit; m += i) {

sieve[m] = 0;

}

}

}

// Return the greatest prime less than or equal to limit:

for (i = limit; i >= 2; --i) {

if (sieve[i] != 0) {

return i;

}

}

return 0;

}

int main()

{

RWTThreadIOUFunction<int> lastprime

= RWTThreadIOUFunction<int>::make(rwBind(greatestPrime, 6000000));

lastprime.start(); // spawn thread to calculate big prime

RWTIOUResult<int> answer = lastprime.result(); // get an IOU

// While the thread is busy calculating, print this

// suspenseful message to keep the user entertained:

std::cout << "The greatest prime less than six million is... "

<< std::flush;

// Block until the answer has been calculated and

// then print it:

std::cout << answer.redeem() << std::endl;

return 0;

}

OUTPUT:
The greatest prime less than six million is... 5999993

See also: RWTFunctor, RWThread, RWRunnable, RWRunnableHandle, RWThreadAttribute

Constructor & Destructor Documentation

template<class Return >

RWTThreadIOUFunction< Return >::RWTThreadIOUFunction ( )

inline

Constructs an empty RWTThreadIOUFunction handle instance.

template<class Return >

RWTThreadIOUFunction< Return >::RWTThreadIOUFunction ( const RWTThreadIOUFunction< Return > & second )

inline

Binds a new handle to the runnable instance, if any, pointed to by the handle second.

template<class Return >

RWTThreadIOUFunction< Return >::~RWTThreadIOUFunction ( )

inline

Destructor.

Member Function Documentation

template<class Return>

RWTFunctor<Return()> RWTThreadIOUFunction< Return >::getFunctor ( ) const

Gets the current functor instance, if any, associated with the runnable. Possible exceptions include RWTHRInvalidPointer and RWTHRInternalError.

template<class Return>

static RWTThreadIOUFunction<Return> RWTThreadIOUFunction< Return >::make ( )

static

Constructs and returns an RWTThreadIOUFunction object with an undefined functor. The setFunctor() member must be used to define a functor prior to starting.

template<class Return>

static RWTThreadIOUFunction<Return> RWTThreadIOUFunction< Return >::make ( const RWTFunctor< Return()> & functor )

static

Constructs and returns an RWTThreadIOUFunction that executes the specified functor when started.

template<class Return>

static RWTThreadIOUFunction<Return> RWTThreadIOUFunction< Return >::make	(	const RWTIOUEscrow< Return > &	escrow,
		const RWTFunctor< Return()> &	functor
	)

static

Constructs and returns an RWTThreadIOUFunction that executes the specified functor when started, and places the functor result in escrow.

template<class Return>

static RWTThreadIOUFunction<Return> RWTThreadIOUFunction< Return >::make	(	const RWTFunctor< Return()> &	functor,
		const RWThreadAttribute &	attr
	)

static

Constructs and returns an RWTThreadIOUFunction that executes the specified functor when started. A new thread is created using the attributes given by attr.

template<class Return>

static RWTThreadIOUFunction<Return> RWTThreadIOUFunction< Return >::make	(	const RWTIOUEscrow< Return > &	escrow,
		const RWTFunctor< Return()> &	functor,
		const RWThreadAttribute &	attr
	)

static

Constructs and returns an RWTThreadIOUFunction that executes the specified functor when started. A new thread is created using the attributes given by attr, and the functor result is stored in escrow.

template<class Return>

RWTIOUResult<Return> RWTThreadIOUFunction< Return >::operator() ( ) const

Returns the IOU that will receive the result of the function.

template<class Return >

RWTThreadIOUFunction< Return > & RWTThreadIOUFunction< Return >::operator= ( const RWTThreadIOUFunction< Return > & second )

inline

Binds this to the runnable instance, if any, pointed to by the handle second.

template<class Return>

RWTIOUResult<Return> RWTThreadIOUFunction< Return >::result ( ) const

Returns the IOU that will receive the result of the function.

template<class Return>

void RWTThreadIOUFunction< Return >::setFunctor ( const RWTFunctor< Return()> & functor )

Sets the functor to be executed by this runnable. Possible exceptions include RWTHRInvalidPointer and RWTHRInternalError.

template<class Return>

void RWTThreadIOUFunction< Return >::setIOUEscrow ( const RWTIOUEscrow< Return > & escrow )

Specifies an IOU escrow that is to receive the result of the function. The new IOU is not used until the next time start() is called. Each time an RWTThreadIOUFunction object is restarted, it checks its current IOU escrow handle to see if it is valid, and if so, checks to see whether the escrow has already been used to capture a result or exception, or has been aborted. If the escrow object is found to be in any of these "redeemable" states, a new escrow instance is automatically created to capture the next result. Possible exceptions include RWTHRInvalidPointer and RWTHRInternalError.

SourcePro® API Reference Guide

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

template<class Return> class RWTThreadIOUFunction< Return >

Constructor & Destructor Documentation

Member Function Documentation

template<class Return>
class RWTThreadIOUFunction< Return >