ServiceFactory

class cppmicroservices::ServiceFactory

A factory for bundle scope services.

The factory can provide service objects unique to each bundle.

When registering a service, a ServiceFactory object can be used instead of a service object, so that the bundle developer can create a customized service object for each bundle that is using the service.

When a bundle requests the service object, the framework calls the ServiceFactory::GetService method to return a service object customized for the requesting bundle. The returned service object is cached by the framework for subsequent calls to BundleContext::GetService(const ServiceReference&) until the bundle releases its use of the service.

When the bundle’s use count for the service is decremented to zero (including the bundle stopping or the service being unregistered), the framework will call the ServiceFactory::UngetService method.

ServiceFactory objects are only used by the framework and are not made available to other bundles in the bundle environment. The framework may concurrently call a ServiceFactory.

See
BundleContext::GetService
See
PrototypeServiceFactory
Remark
This class is thread safe.

Subclassed by cppmicroservices::PrototypeServiceFactory

Public Functions

virtual ~ServiceFactory()
virtual InterfaceMapConstPtr GetService(const Bundle &bundle, const ServiceRegistrationBase &registration) = 0

Returns a service object for a bundle.

The framework invokes this method the first time the specified bundle requests a service object using the BundleContext::GetService(const ServiceReferenceBase&) method. The factory can then return a customized service object for each bundle.

The framework checks that the returned service object is valid. If the returned service object is null or does not contain entries for all the classes named when the service was registered, a framework event of type FrameworkEvent::FRAMEWORK_ERROR is fired containing a service exception of type ServiceException::FACTORY_ERROR and null is returned to the bundle. If this method throws an exception, a framework event of type FrameworkEvent::FRAMEWORK_ERROR is fired containing a service exception of type ServiceException::FACTORY_EXCEPTION with the thrown exception as a nested exception and null is returned to the bundle. If this method is recursively called for the specified bundle, a framework event of type FrameworkEvent::FRAMEWORK_ERROR is fired containing a service exception of type ServiceException::FACTORY_RECURSION and null is returned to the bundle.

The framework caches the valid service object, and will return the same service object on any future call to BundleContext::GetService for the specified bundle. This means the framework does not allow this method to be concurrently called for the specified bundle.

Return
A service object that must contain entries for all the interfaces named when the service was registered.
See
BundleContext::GetService
See
InterfaceMapConstPtr
Parameters
  • bundle: The bundle requesting the service.
  • registration: The ServiceRegistrationBase object for the requested service.

virtual void UngetService(const Bundle &bundle, const ServiceRegistrationBase &registration, const InterfaceMapConstPtr &service) = 0

Releases a service object customized for a bundle.

The Framework invokes this method when a service has been released by a bundle. If this method throws an exception, a framework event of type FrameworkEvent::FRAMEWORK_ERROR is fired containing a service exception of type ServiceException::FACTORY_EXCEPTION with the thrown exception as a nested exception.

See
InterfaceMapConstPtr
Parameters