Stream handler for synchronous streams. More...

#include <cvb/async/stream_handler_base.hpp>

Public Types
using	StreamType = STREAMTYPE
	Shorthand notation of the stream type.

using	StreamPtrType = std::shared_ptr<StreamType>
	Shorthand notation of the shared pointer of the specified stream.

using	StreamVectorType = std::vector<StreamPtrType>
	Shorthand notation of the container of the stream shared pointer.

using	DeliverableType = typename Internal::DeliverableTraits<STREAMTYPE>::type
	Shorthand notation of the stream deliverable type of the specified stream.

using	DeliverablePtrType = std::shared_ptr<typename Internal::DeliverableTraits<STREAMTYPE>::type>
	Shorthand notation of the shared pointer of the stream deliverable.

using	DeliverablePtrVectorType = std::vector<DeliverablePtrType>
	Shorthand notation of the container of the stream deliverable shared pointers.

using	EventHandlerType = std::function<void(DeliverablePtrType, Cvb::WaitStatus)>
	Shorthand notation of the event handler, a callable, type.

using	EventHandlerVectorType = std::vector<EventHandlerType>
	Shorthand notation of the container of the event handler.

Public Member Functions
void	Run ()
	Start the handler.

bool	TryFinish () noexcept
	Stop the handler.

void	Finish ()
	Stop the handler.

bool	IsActive () const noexcept
	Check if the acquisition thread is running.

Static Public Member Functions
static std::unique_ptr< StreamHandlerBase >	Create (const StreamVectorType &streamVector)
	Create a stream handler object.

static std::unique_ptr< StreamHandlerBase >	Create (const StreamPtrType &stream)
	Create a stream handler object.

Protected Member Functions
	StreamHandlerBase (const StreamVectorType &streamVector)
	Creates a stream handler object.

	StreamHandlerBase (const StreamPtrType &stream)
	Creates a stream handler object.

virtual void	HandleAsyncStream (const StreamVectorType &streamVector)
	Asynchronously called for all registered streams.

virtual void	HandleAsyncWaitResult (const std::vector< WaitResult< typename Internal::DeliverableTraits< STREAMTYPE >::type > > &waitResultVector)
	Asynchronously called for all acquired images.

virtual void	HandleAsyncWaitResult (const std::vector< WaitResultTuple< typename Internal::DeliverableTraits< STREAMTYPE >::type > > &waitResultVector)
	Asynchronously called for all acquired images.

virtual void	Setup (const StreamVectorType streamVector)
	Setup the streams for acquisition.

virtual void	TearDown (const StreamVectorType streamVector) noexcept
	Tear down the streams after acquisition.

virtual void	HandleError (const std::exception &error) noexcept
	Handles standard exceptions in the acquisition thread.

virtual void	Begin () noexcept
	Performs custom operations at the beginning of the acquisition thread.

virtual void	End () noexcept
	Performs custom operations just before the end of the acquisition thread.

std::vector< StreamPtrType >	StreamVector () const noexcept
	Get the streams associated with this handler.

Detailed Description

template<class STREAMTYPE>
class Cvb::StreamHandlerBase< STREAMTYPE >

Stream handler for synchronous streams.

Template Parameters

STREAMTYPE Type of stream to be taken care of.

Constructor & Destructor Documentation

◆ StreamHandlerBase() [1/2]

template<class STREAMTYPE>

StreamHandlerBase ( const StreamVectorType & streamVector )

inlineexplicitprotected

Creates a stream handler object.

Parameters

[in] streamVector List with synchronous streams.

Exceptions

Any	exception derived from std::exception including CvbException.

Call this in a customized subclass to setup the handler.

◆ StreamHandlerBase() [2/2]

template<class STREAMTYPE>

StreamHandlerBase ( const StreamPtrType & stream )

inlineexplicitprotected

Creates a stream handler object.

Parameters

[in] stream Synchronous stream.

Exceptions

Any	exception derived from std::exception including CvbException.

Call this in a customized subclass to setup the handler.

Member Function Documentation

◆ Begin()

template<class STREAMTYPE>

virtual void Begin ( )

inlineprotectedvirtualnoexcept

Performs custom operations at the beginning of the acquisition thread.

Exceptions

Does	not throw any exception.

The default implementation does nothing. Be aware, that this method is called from the acquisition thread. Reimplemented it to setup resources that require the acquisition thread up and running. This is useful for interaction with Qt. E.g. you may create QObject derived classes here to archive correct thread affinity.

◆ Create() [1/2]

template<class STREAMTYPE>

static std::unique_ptr< StreamHandlerBase > Create ( const StreamPtrType & stream )

inlinestatic

Create a stream handler object.

Parameters

[in] stream Synchronous stream.

Returns: A stream handler object.

Exceptions

Any	exception derived from std::exception including CvbException.

This overload can be helpful if it is obvious that the number of streams is limited to one.

Note: You must not destroy a stream handler that is currently running. In order to prevent that you may use a StreamHandlerGuard.

◆ Create() [2/2]

template<class STREAMTYPE>

static std::unique_ptr< StreamHandlerBase > Create ( const StreamVectorType & streamVector )

inlinestatic

Create a stream handler object.

Parameters

[in] streamVector List with synchronous streams.

Returns: A stream handler object.

Exceptions

Any	exception derived from std::exception including CvbException.

Note: You must not destroy a stream handler that is currently running. In order to prevent that you may use a StreamHandlerGuard.

◆ End()

template<class STREAMTYPE>

virtual void End ( )

inlineprotectedvirtualnoexcept

Performs custom operations just before the end of the acquisition thread.

Exceptions

Does	not throw any exception.

The default implementation does nothing. Be aware, that this method is called from the acquisition thread. Reimplemented it to free resources that have been allocated in Begin().

◆ Finish()

template<class STREAMTYPE>

void Finish ( )

inline

Stop the handler.

Exceptions

Any	exception derived from std::exception including CvbException this also includes the last error on the acquisition thread.

This will stop the acquisition thread and call TearDown() on the calling thread. This blocks until the acquisition thread has finished, so blocking in a customized HandleAsyncStream() method can lead to deadlocks.

Note: If the acquisition handler is destroyed it automatically finishes.

◆ HandleAsyncStream()

template<class STREAMTYPE>

void HandleAsyncStream ( const StreamVectorType & streamVector )

inlineprotectedvirtual

Asynchronously called for all registered streams.

Parameters

[in] streamVector List with synchronous streams (provided at creation).

Exceptions

Any	exception derived from std::exception including CvbException.

The default implementation just waits for the next image on each stream.

Attention: This method is called on a dedicated thread!

◆ HandleAsyncWaitResult() [1/2]

template<class STREAMTYPE>

void HandleAsyncWaitResult ( const std::vector< WaitResult< typename Internal::DeliverableTraits< STREAMTYPE >::type > > & waitResultVector )

inlineprotectedvirtual

Asynchronously called for all acquired images.

Parameters

[in] waitResultVector List with synchronous acquired WaitResults.

Exceptions

Any	exception derived from std::exception including CvbException.

The default implementation does nothing.

Attention: This method is called on a dedicated thread!

◆ HandleAsyncWaitResult() [2/2]

template<class STREAMTYPE>

void HandleAsyncWaitResult ( const std::vector< WaitResultTuple< typename Internal::DeliverableTraits< STREAMTYPE >::type > > & waitResultVector )

inlineprotectedvirtual

Asynchronously called for all acquired images.

Parameters

[in] waitResultVector List with synchronous acquired WaitResults.

Exceptions

Any	exception derived from std::exception including CvbException.

The default implementation does nothing.

Attention: This method is called on a dedicated thread!

◆ HandleError()

template<class STREAMTYPE>

void HandleError ( const std::exception & error )

inlineprotectedvirtualnoexcept

Handles standard exceptions in the acquisition thread.

Parameters

[in] &error The exception thrown.

Exceptions

Does	not throw any exception.

This handler is called for all not explicitly handled standard exception in the acquisition thread. After the handler returned the acquisition thread may finish, but remain in the active state. Be aware that this handler is by default called from the acquisition thread.

Note: After this handler there will be no automatic call to TearDown(). So you have to call Finish() explicitly. If you reimplemented this handler you should call the default implementation so Finish() will deliver the error into the controlling thread, otherwise the error will be swallowed within the acquisition thread.

◆ IsActive()

template<class STREAMTYPE>

bool IsActive ( ) const

inlinenoexcept

Check if the acquisition thread is running.

Returns: True if running otherwise false.

Exceptions

Does	not throw any exception.

◆ Run()

template<class STREAMTYPE>

void Run ( )

inline

Start the handler.

Exceptions

Any	exception derived from std::exception including CvbException.

This will call Setup() on the calling thread, before creating a dedicated acquisition thread. The acquisition thread will repeatedly call HandleAsyncStream().

◆ Setup()

template<class STREAMTYPE>

void Setup ( const StreamVectorType streamVector )

inlineprotectedvirtual

Setup the streams for acquisition.

Parameters

[in] streamVector List with synchronous streams (provided at creation).

Exceptions

Any	exception derived from std::exception including CvbException.

The default implementation just calls Stream::Start() for each stream.

◆ StreamVector()

template<class STREAMTYPE>

std::vector< StreamPtrType > StreamVector ( ) const

inlineprotectednoexcept

Get the streams associated with this handler.

Returns: Stream vector.

Exceptions

Does	not throw any exception.

◆ TearDown()

template<class STREAMTYPE>

void TearDown ( const StreamVectorType streamVector )

inlineprotectedvirtualnoexcept

Tear down the streams after acquisition.

Parameters

[in] streamVector List with synchronous streams (provided at creation).

Exceptions

Does	not throw any exception.

The default implementation just calls Stream::TryAbort() for each stream.

◆ TryFinish()

template<class STREAMTYPE>

bool TryFinish ( )

inlinenoexcept

Stop the handler.

Returns: True if no error occurred in the acquisition thread, otherwise.

Exceptions

Does	not throw any exception.

This will stop the acquisition thread and call TearDown() on the calling thread. This blocks until the acquisition thread has finished, so blocking in a customized HandleAsyncStream() method can lead to deadlocks.

Note: If the acquisition handler is destroyed it automatically finishes.

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ StreamHandlerBase() [1/2]

◆ StreamHandlerBase() [2/2]

Member Function Documentation

◆ Begin()

◆ Create() [1/2]

◆ Create() [2/2]

◆ End()

◆ Finish()

◆ HandleAsyncStream()

◆ HandleAsyncWaitResult() [1/2]

◆ HandleAsyncWaitResult() [2/2]

◆ HandleError()

◆ IsActive()

◆ Run()

◆ Setup()

◆ StreamVector()

◆ TearDown()

◆ TryFinish()