GaudiHandle< T > Class Template Reference

Handle to be used in lieu of naked pointers to gaudis. More...

#include <GaudiKernel/GaudiHandle.h>

Inheritance diagram for GaudiHandle< T >:

Collaboration diagram for GaudiHandle< T >:

Public Member Functions
template<typename CT = T, typename NCT = std::remove_const_t<T>> requires ( std::is_const_v<CT> && !std::is_same_v<CT, NCT> )
	GaudiHandle (const GaudiHandle< NCT > &other)
	Copy constructor needed for correct ref-counting.
	GaudiHandle (const GaudiHandle &other)
	Copy constructor needed for correct ref-counting.
template<typename CT = T, typename NCT = std::remove_const_t<T>> requires ( std::is_const_v<CT> && !std::is_same_v<CT, NCT> )
GaudiHandle &	operator= (const GaudiHandle< NCT > &other)
	Assignment operator for correct ref-counting.
GaudiHandle &	operator= (const GaudiHandle &other)
	Assignment operator for correct ref-counting.
StatusCode	retrieve () const
	Retrieve the component.
StatusCode	release () const
	Release the component.
bool	isValid () const
	Check if the handle is valid (try to retrive the object is not done yet).
	operator bool () const
	For testing if handle has component.
T *	get ()
	Return the wrapped pointer, not calling retrieve() if null.
std::add_const_t< T > *	get () const
	Return the wrapped pointer, not calling retrieve() if null.
bool	isSet () const
	True if the wrapped pointer is not null.
T &	operator* ()
T *	operator-> ()
std::add_const_t< T > &	operator* () const
std::add_const_t< T > *	operator-> () const
std::string	getDefaultType ()
	Helper function to get default type string from the class type.
std::string	getDefaultName ()
Public Member Functions inherited from GaudiHandleBase
const std::string &	typeAndName () const
	The full type and name: "type/name".
std::string	type () const
	The concrete component class name: the part before the '/'.
std::string	name () const
	The instance name: the part after the '/'.
bool	empty () const
	Check if the handle has been set to empty string (i.e.
void	setTypeAndName (std::string myTypeAndName)
	The component "type/name" string.
void	setName (std::string_view myName)
	Set the instance name (part after the '/') without changing the class type.
std::string	pythonPropertyClassName () const override
	Name of the componentType with "Handle" appended.
std::string	messageName () const
	name used for printing messages
std::string	pythonRepr () const override
	Python representation of handle, i.e.
Public Member Functions inherited from GaudiHandleInfo
virtual	~GaudiHandleInfo ()
	virtual destructor so that derived class destructor is called.
const std::string &	componentType () const
const std::string &	propertyName () const
	name as used in declareProperty(name,gaudiHandle)
void	setPropertyName (std::string propName)
	set name as used in declareProperty(name,gaudiHandle).
const std::string &	parentName () const
	The name of the parent.

Protected Member Functions
	GaudiHandle (std::string myTypeAndName, std::string myComponentType, std::string myParentName)
virtual StatusCode	retrieve (T *&) const =0
	Retrieve the component.
virtual StatusCode	release (T *comp) const
	Release the component.
Protected Member Functions inherited from GaudiHandleBase
	GaudiHandleBase (std::string myTypeAndName, std::string myComponentType, std::string myParentName)
	Create a handle ('smart pointer') to a gaudi component.
Protected Member Functions inherited from GaudiHandleInfo
	GaudiHandleInfo (std::string myComponentType, std::string myParentName)
	Some basic information and helper functions shared between various handles/arrays.
void	setComponentType (std::string componentType)
	The component type.
void	setParentName (std::string parent)
	The name of the parent.

Private Member Functions
void	assertObject () const
	Load the pointer to the component.

Private Attributes
std::atomic< T * >	m_pObject = nullptr

Additional Inherited Members
Public Types inherited from GaudiHandleBase
using	PropertyType = GaudiHandleProperty

Detailed Description

template<class T>
class GaudiHandle< T >

Handle to be used in lieu of naked pointers to gaudis.

This allows better control through the framework of gaudi loading and usage. T is the type of the component interface (or concrete class).

Author

Marti.nosp@m.n.Wo.nosp@m.udstr.nosp@m.a@ce.nosp@m.rn.ch

Definition at line 176 of file GaudiHandle.h.

Constructor & Destructor Documentation

GaudiHandle() [1/3]

template<class T>

GaudiHandle< T >::GaudiHandle ( std::string myTypeAndName, std::string myComponentType, std::string myParentName )

inlineprotected

Definition at line 181 of file GaudiHandle.h.

      : GaudiHandleBase( std::move( myTypeAndName ), std::move( myComponentType ), std::move( myParentName ) ) {}

GaudiHandle() [2/3]

template<class T>

template<typename CT = T, typename NCT = std::remove_const_t<T>>
requires ( std::is_const_v<CT> && !std::is_same_v<CT, NCT> )

GaudiHandle< T >::GaudiHandle ( const GaudiHandle< NCT > & other )

inline

Copy constructor needed for correct ref-counting.

Definition at line 187 of file GaudiHandle.h.

      : GaudiHandleBase( other ), m_pObject( other.get() ) {
    if ( m_pObject ) ::details::nonConst( m_pObject.load() )->addRef();
  }

GaudiHandle() [3/3]

template<class T>

GaudiHandle< T >::GaudiHandle ( const GaudiHandle< T > & other )

inline

Copy constructor needed for correct ref-counting.

Definition at line 194 of file GaudiHandle.h.

                                          : GaudiHandleBase( other ), m_pObject( other.m_pObject.load() ) {
    if ( m_pObject ) ::details::nonConst( m_pObject.load() )->addRef();
  }

Member Function Documentation

assertObject()

template<class T>

void GaudiHandle< T >::assertObject ( ) const

inlineprivate

Load the pointer to the component.

Do a retrieve if needed. Throw an exception if retrieval fails.

Definition at line 314 of file GaudiHandle.h.

                            { // not really const, because it may update m_pObject
    if ( !isValid() ) {
      throw GaudiException( "Failed to retrieve " + componentType() + ": " + typeAndName(),
                            componentType() + " retrieve", StatusCode::FAILURE );
    }
  }

get() [1/2]

template<class T>

T * GaudiHandle< T >::get ( )

inline

Return the wrapped pointer, not calling retrieve() if null.

Definition at line 261 of file GaudiHandle.h.

{ return m_pObject; }

get() [2/2]

template<class T>

std::add_const_t< T > * GaudiHandle< T >::get ( ) const

inline

Return the wrapped pointer, not calling retrieve() if null.

Definition at line 264 of file GaudiHandle.h.

{ return m_pObject; }

getDefaultName()

template<class T>

std::string GaudiHandle< T >::getDefaultName ( )

inline

Definition at line 294 of file GaudiHandle.h.

                             {
    const auto defName = GaudiHandleBase::type();
    return ( defName.empty() ? getDefaultType() : defName );
  }

getDefaultType()

template<class T>

std::string GaudiHandle< T >::getDefaultType ( )

inline

Helper function to get default type string from the class type.

Definition at line 292 of file GaudiHandle.h.

{ return System::typeinfoName( typeid( T ) ); }

isSet()

template<class T>

bool GaudiHandle< T >::isSet ( ) const

inline

True if the wrapped pointer is not null.

Definition at line 267 of file GaudiHandle.h.

{ return get(); }

isValid()

template<class T>

bool GaudiHandle< T >::isValid ( ) const

inline

Check if the handle is valid (try to retrive the object is not done yet).

Definition at line 248 of file GaudiHandle.h.

                       {
    // not really const, because it may update m_pObject
    return m_pObject || retrieve().isSuccess();
  }

operator bool()

template<class T>

GaudiHandle< T >::operator bool ( ) const

inline

For testing if handle has component.

Does retrieve() if needed. If this returns false, the component could not be retrieved.

Definition at line 255 of file GaudiHandle.h.

                        {
    // not really const, because it may update m_pObject
    return isValid();
  }

operator*() [1/2]

template<class T>

T & GaudiHandle< T >::operator* ( )

inline

Definition at line 269 of file GaudiHandle.h.

                 {
    assertObject();
    return *m_pObject;
  }

operator*() [2/2]

template<class T>

std::add_const_t< T > & GaudiHandle< T >::operator* ( ) const

inline

Definition at line 279 of file GaudiHandle.h.

                                       {
    // not really const, because it may update m_pObject
    assertObject();
    return *m_pObject;
  }

operator->() [1/2]

template<class T>

T * GaudiHandle< T >::operator-> ( )

inline

Definition at line 274 of file GaudiHandle.h.

                  {
    assertObject();
    return m_pObject;
  }

operator->() [2/2]

template<class T>

std::add_const_t< T > * GaudiHandle< T >::operator-> ( ) const

inline

Definition at line 285 of file GaudiHandle.h.

                                        {
    // not really const, because it may update m_pObject
    assertObject();
    return m_pObject;
  }

operator=() [1/2]

template<class T>

GaudiHandle & GaudiHandle< T >::operator= ( const GaudiHandle< T > & other )

inline

Assignment operator for correct ref-counting.

Definition at line 212 of file GaudiHandle.h.

                                                     {
    GaudiHandleBase::operator=( other );
    // release any current tool
    release().ignore();
    m_pObject = other.m_pObject.load();
    // update ref-counting
    if ( m_pObject ) ::details::nonConst( m_pObject.load() )->addRef();
    return *this;
  }

operator=() [2/2]

template<class T>

template<typename CT = T, typename NCT = std::remove_const_t<T>>
requires ( std::is_const_v<CT> && !std::is_same_v<CT, NCT> )

GaudiHandle & GaudiHandle< T >::operator= ( const GaudiHandle< NCT > & other )

inline

Assignment operator for correct ref-counting.

Definition at line 201 of file GaudiHandle.h.

                                                          {
    GaudiHandleBase::operator=( other );
    // release any current tool
    release().ignore();
    m_pObject = other.get();
    // update ref-counting
    if ( m_pObject ) ::details::nonConst( m_pObject.load() )->addRef();
    return *this;
  }

release() [1/2]

template<class T>

StatusCode GaudiHandle< T >::release ( ) const

inline

Release the component.

Definition at line 237 of file GaudiHandle.h.

                             {
    // not really const, because it updates m_pObject
    StatusCode sc = StatusCode::SUCCESS;
    if ( m_pObject ) {
      sc        = release( m_pObject );
      m_pObject = nullptr;
    }
    return sc;
  }

release() [2/2]

template<class T>

virtual StatusCode GaudiHandle< T >::release ( T * comp ) const

inlineprotectedvirtual

Release the component.

Default implementation calls release() on the component. Can be overridden by the derived class if something else is needed.

Reimplemented in ToolHandle< T >, ToolHandle< const IMyTool >, ToolHandle< Gaudi::Tests::Histograms::Directories::HistoGroupsTool >, ToolHandle< Gaudi::TestSuite::FloatTool >, ToolHandle< GaudiTesting::ITestTool >, ToolHandle< IAlgTool >, ToolHandle< IMyTool >, ToolHandle< IThreadInitTool >, and ToolHandle< IWrongTool >.

Definition at line 305 of file GaudiHandle.h.

                                              { // not really const, because it updates m_pObject
    // const cast to support T being a const type
    ::details::nonConst( comp )->release();
    return StatusCode::SUCCESS;
  }

retrieve() [1/2]

template<class T>

StatusCode GaudiHandle< T >::retrieve ( ) const

inline

Retrieve the component.

Release existing component if needed.

Definition at line 223 of file GaudiHandle.h.

                              {
    // not really const, because it updates m_pObject
    // Do the lookup into a temporary pointer.
    T* p = nullptr;
    if ( retrieve( p ).isFailure() ) { return StatusCode::FAILURE; }
 
    // If m_pObject is null, then copy p to m_pObject.
    // Otherwise, release p.
    T* old = nullptr;
    if ( m_pObject.compare_exchange_strong( old, p ) ) { return StatusCode::SUCCESS; }
    return release( p );
  }

retrieve() [2/2]

template<class T>

virtual StatusCode GaudiHandle< T >::retrieve ( T *& ) const

protectedpure virtual

Retrieve the component.

To be implemented by the derived class. It will pass the pointer

Implemented in ServiceHandle< T >, ServiceHandle< Gaudi::Example::TinyExperiment::IRandomGenSvc >, ServiceHandle< Gaudi::Interfaces::IFileSvc >, ServiceHandle< Gaudi::TestSuite::SvcWithoutInterface >, ServiceHandle< IAlgContextSvc >, ServiceHandle< IFileMgr >, ServiceHandle< IIncidentSvc >, ServiceHandle< IInterface >, ServiceHandle< INTupleSvc >, ServiceHandle< IPartPropSvc >, ServiceHandle< ITHistSvc >, ServiceHandle< IToolSvc >, ToolHandle< T >, ToolHandle< const IMyTool >, ToolHandle< Gaudi::Tests::Histograms::Directories::HistoGroupsTool >, ToolHandle< Gaudi::TestSuite::FloatTool >, ToolHandle< GaudiTesting::ITestTool >, ToolHandle< IAlgTool >, ToolHandle< IMyTool >, ToolHandle< IThreadInitTool >, and ToolHandle< IWrongTool >.

Member Data Documentation

m_pObject

template<class T>

std::atomic<T*> GaudiHandle< T >::m_pObject = nullptr

mutableprivate

Definition at line 325 of file GaudiHandle.h.

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

• GaudiKernel/include/GaudiKernel/GaudiHandle.h