lunchbox::RequestHandler Class Reference

A thread-safe request handler. More...

#include <requestHandler.h>

Inheritance diagram for lunchbox::RequestHandler:

Collaboration diagram for lunchbox::RequestHandler:

Public Member Functions
LUNCHBOX_API	RequestHandler ()
	Construct a new request handler. More...
LUNCHBOX_API	~RequestHandler ()
	Destruct the request handler. More...
template<class T >
Request< T >	registerRequest (void *data=0)
	Register a request. More...
uint32_t	registerRequest (void *data=0) LB_DEPRECATED
	Register a request. More...
LUNCHBOX_API void	unregisterRequest (const uint32_t requestID)
	Unregister a request. More...
LUNCHBOX_API bool	waitRequest (const uint32_t requestID, void *&result, const uint32_t timeout=LB_TIMEOUT_INDEFINITE)
	Wait a given time for the completion of a request. More...
LUNCHBOX_API bool	waitRequest (const uint32_t requestID, uint32_t &result, const uint32_t timeout=LB_TIMEOUT_INDEFINITE)
	Wait for a request with an uint32_t result. More...
LUNCHBOX_API bool	waitRequest (const uint32_t requestID, bool &result, const uint32_t timeout=LB_TIMEOUT_INDEFINITE)
	Wait for a request with a bool result. More...
LUNCHBOX_API bool	waitRequest (const uint32_t requestID, servus::uint128_t &result, const uint32_t timeout=LB_TIMEOUT_INDEFINITE)
	Wait for a request with an uint128_t result. More...
LUNCHBOX_API bool	waitRequest (const uint32_t requestID)
	Wait for a request without a result. More...
bool	isRequestServed (const uint32_t id) const LB_DEPRECATED
	Poll for the completion of a request. More...
LUNCHBOX_API void *	getRequestData (const uint32_t requestID)
	Retrieve the user-specific data for a request. More...
LUNCHBOX_API void	serveRequest (const uint32_t requestID, void *result=0)
	Serve a request with a void* result. More...
LUNCHBOX_API void	serveRequest (const uint32_t requestID, uint32_t result)
	Serve a request with an uint32_t result. More...
LUNCHBOX_API void	serveRequest (const uint32_t requestID, bool result)
	Serve a request with a bool result. More...
LUNCHBOX_API void	serveRequest (const uint32_t requestID, const servus::uint128_t &result)
	Serve a request with an uint128_t result. More...
LUNCHBOX_API bool	hasPendingRequests () const
LUNCHBOX_API bool	isRequestReady (const uint32_t) const

Friends
LUNCHBOX_API std::ostream &	operator<< (std::ostream &, const RequestHandler &)

Detailed Description

A thread-safe request handler.

Different execution threads can synchronize using a request handler. One thread registers a request, and later waits for the request to be served. Another thread can serve the request, providing a result value.

Thread-safety: The methods registerRequest(), unregisterRequest() and waitRequest() are supposed to be called from one 'waiting' thread, and the functions serveRequest() and deleteRequest() are supposed to be called only from one 'serving' thread.

Example:

/* Copyright (c) 2013-2014, Stefan.Eilemann@epfl.ch
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifdef WARN_DEPRECATED
#  undef WARN_DEPRECATED
#endif

#include "test.h"

#include <lunchbox/mtQueue.h>
#include <lunchbox/requestHandler.h>
#include <lunchbox/sleep.h>
#include <lunchbox/thread.h>
#include <servus/uint128_t.h>

using servus::uint128_t;

lunchbox::RequestHandler handler_;
lunchbox::MTQueue< uint32_t > requestQ_;
const uint128_t uuid = servus::make_UUID();

class Thread : public lunchbox::Thread
{
public:
    virtual void run() final
    {
        const bool boolIn = true;
        uint8_t* payload = (uint8_t*)42;

        uint32_t request = requestQ_.pop();
        TEST( handler_.getRequestData( request ) == ++payload );
        handler_.serveRequest( request, boolIn );

        const uint32_t uint32In = 0xC0FFEE;
        request = requestQ_.pop();
        TEST( handler_.getRequestData( request ) == ++payload );
        handler_.serveRequest( request, uint32In );

        request = requestQ_.pop();
        TEST( handler_.getRequestData( request ) == ++payload );
        handler_.serveRequest( request );

        request = requestQ_.pop();
        TESTINFO( handler_.getRequestData( request ) == ++payload,
                  (size_t)handler_.getRequestData( request ) << " for " <<
                  request );
        handler_.serveRequest( request );

        request = requestQ_.pop();
        TEST( handler_.getRequestData( request ) == ++payload );
        handler_.serveRequest( request, uuid );
    }
};

int main( int, char** )
{
    uint8_t* payload = (uint8_t*)42;
    Thread thread;
    thread.start();

    uint32_t request = handler_.registerRequest( ++payload );
    requestQ_.push( request );
    bool boolOut = false;
    TEST( handler_.waitRequest( request, boolOut ));
    TEST( boolOut == true );

    lunchbox::Request< uint32_t > future =
        handler_.registerRequest< uint32_t >( ++payload );
    requestQ_.push( future.getID( ));

    request = handler_.registerRequest( ++payload );
    requestQ_.push( request );
    TEST( handler_.waitRequest( request ));

    lunchbox::Request< void > voidFuture =
        handler_.registerRequest< void >( ++payload );
    lunchbox::Request< uint128_t > uint128Future =
        handler_.registerRequest< uint128_t >( ++payload );

    requestQ_.push( voidFuture.getID( ));
    requestQ_.push( uint128Future.getID( ));

    TEST( future.wait( ) == 0xC0FFEE );
    TEST( future.wait( ));
    TEST( uint128Future.wait() == uuid );
    TEST( handler_.isRequestServed( voidFuture.getID( )));

    TEST( thread.join( ));
    return EXIT_SUCCESS;
}

Definition at line 44 of file requestHandler.h.

Constructor & Destructor Documentation

LUNCHBOX_API lunchbox::RequestHandler::RequestHandler

(

)

Construct a new request handler.

Version

1.0

LUNCHBOX_API lunchbox::RequestHandler::~RequestHandler

(

)

Destruct the request handler.

Member Function Documentation

LUNCHBOX_API void* lunchbox::RequestHandler::getRequestData

(

const uint32_t

requestID

)

Retrieve the user-specific data for a request.

Parameters

requestID

the request identifier.

Returns

the user-specific data for the request.

Version

1.0

LUNCHBOX_API bool lunchbox::RequestHandler::hasPendingRequests

(

)

const

Returns

true if this request handler has pending requests.

Version

1.0

bool lunchbox::RequestHandler::isRequestServed ( const uint32_t  id ) const

inline

Poll for the completion of a request.

Version

1.0

Deprecated:

use Request::isReady()

Definition at line 123 of file requestHandler.h.

template<class T >

Request< T > lunchbox::RequestHandler::registerRequest ( void *  data = 0 )

inline

Register a request.

Parameters

data	a pointer to user-specific data for the request, can be 0.

Returns

A Future which will be fulfilled on serveRequest().

Version

1.9.1

Definition at line 176 of file requestHandler.h.

uint32_t lunchbox::RequestHandler::registerRequest ( void *  data = 0 )

inline

Register a request.

Parameters

data	a pointer to user-specific data for the request, can be 0.

Returns

the request identifier.

Version

1.0

Deprecated:

use the future-based registerRequest()

Definition at line 72 of file requestHandler.h.

LUNCHBOX_API void lunchbox::RequestHandler::serveRequest	(	const uint32_t	requestID,
		void *	result = 0
	)

Serve a request with a void* result.

Parameters

requestID	the request identifier.
result	the result of the request.

Version

1.0

LUNCHBOX_API void lunchbox::RequestHandler::serveRequest	(	const uint32_t	requestID,
		uint32_t	result
	)

Serve a request with an uint32_t result.

Version

1.0

LUNCHBOX_API void lunchbox::RequestHandler::serveRequest	(	const uint32_t	requestID,
		bool	result
	)

Serve a request with a bool result.

Version

1.0

LUNCHBOX_API void lunchbox::RequestHandler::serveRequest	(	const uint32_t	requestID,
		const servus::uint128_t &	result
	)

Serve a request with an uint128_t result.

Version

1.0

LUNCHBOX_API void lunchbox::RequestHandler::unregisterRequest

(

const uint32_t

requestID

)

Unregister a request.

Note that waitRequest automatically unregisters the request when it was successful. This method is only used when a waitRequest has timed out and the request will no longer be used.

Parameters

requestID

the request identifier.

Version

1.0

LUNCHBOX_API bool lunchbox::RequestHandler::waitRequest	(	const uint32_t	requestID,
		void *&	result,
		const uint32_t	timeout = LB_TIMEOUT_INDEFINITE
	)

Wait a given time for the completion of a request.

The request is unregistered upon successful completion, i.e, the when the method returns true.

Parameters

requestID	the request identifier.
result	the result code of the operation.
timeout	the timeout in milliseconds to wait for the request, or LB_TIMEOUT_INDEFINITE to wait indefinitely.

Returns

true if the request was served, false if not.

Version

1.0

Referenced by lunchbox::Request< T >::Impl::wait().

Here is the caller graph for this function:

LUNCHBOX_API bool lunchbox::RequestHandler::waitRequest	(	const uint32_t	requestID,
		uint32_t &	result,
		const uint32_t	timeout = LB_TIMEOUT_INDEFINITE
	)

Wait for a request with an uint32_t result.

Version

1.0

LUNCHBOX_API bool lunchbox::RequestHandler::waitRequest	(	const uint32_t	requestID,
		bool &	result,
		const uint32_t	timeout = LB_TIMEOUT_INDEFINITE
	)

Wait for a request with a bool result.

Version

1.0

LUNCHBOX_API bool lunchbox::RequestHandler::waitRequest	(	const uint32_t	requestID,
		servus::uint128_t &	result,
		const uint32_t	timeout = LB_TIMEOUT_INDEFINITE
	)

Wait for a request with an uint128_t result.

Version

1.0

LUNCHBOX_API bool lunchbox::RequestHandler::waitRequest

(

const uint32_t

requestID

)

Wait for a request without a result.

Version

1.0

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

• requestHandler.h