Gazebo Gazebo

API Reference

6.16.0
ComponentDescriptorQueue Class Reference

A class to hold the queue of component descriptors registered by translation units. This queue is necessary to ensure that component creation continues to work after plugins are unloaded. The typical scenario this aims to solve is: More...

#include <Factory.hh>

Public Member Functions

void IGNITION_GAZEBO_HIDDEN Add (RegistrationObjectId _regObjId, ComponentDescriptorBase *_comp)
 Add a component descriptor to the queue. More...
 
IGNITION_GAZEBO_HIDDEN std::unique_ptr< BaseComponentCreate () const
 Create a component using the latest available component descriptor. This simply forward to ComponentDescriptorBase::Create. More...
 
IGNITION_GAZEBO_HIDDEN std::unique_ptr< BaseComponentCreate (const components::BaseComponent *_data) const
 Create a component using the latest available component descriptor. This simply forward to ComponentDescriptorBase::Create. More...
 
bool IGNITION_GAZEBO_HIDDEN Empty ()
 Check if the queue is empty. More...
 
void IGNITION_GAZEBO_HIDDEN Remove (RegistrationObjectId _regObjId)
 Remove a component descriptor from the queue. This also deletes memory allocated for the component descriptor by the static component registration object. More...
 

Detailed Description

A class to hold the queue of component descriptors registered by translation units. This queue is necessary to ensure that component creation continues to work after plugins are unloaded. The typical scenario this aims to solve is:

  1. Plugin P1 registers component descripter for component C1.
  2. Plugin P1 gets unloaded.
  3. Plugin P2 registers a component descriptor for component C1 and tries to create an instance of C1. When P1 gets unloaded, the destructor of the static component registration object calls Factory::Unregister which removes the component descriptor from the queue. Without this step, P2 would attempt to use the component descriptor created by P1 in step 3 and likely segfault because the memory associated with that descriptor has been deleted when P1 was unloaded.

Member Function Documentation

◆ Add()

void IGNITION_GAZEBO_HIDDEN Add ( RegistrationObjectId  _regObjId,
ComponentDescriptorBase _comp 
)
inline

Add a component descriptor to the queue.

Parameters
[in]_regObjIdAn ID that identifies the registration object. This is generally derived from the this pointer of the static component registration object created when calling IGN_GAZEBO_REGISTER_COMPONENT.
[in]_compThe component descriptor

◆ Create() [1/2]

IGNITION_GAZEBO_HIDDEN std::unique_ptr<BaseComponent> Create ( ) const
inline

Create a component using the latest available component descriptor. This simply forward to ComponentDescriptorBase::Create.

See also
ComponentDescriptorBase::Create

◆ Create() [2/2]

IGNITION_GAZEBO_HIDDEN std::unique_ptr<BaseComponent> Create ( const components::BaseComponent _data) const
inline

Create a component using the latest available component descriptor. This simply forward to ComponentDescriptorBase::Create.

See also
ComponentDescriptorBase::Create

◆ Empty()

bool IGNITION_GAZEBO_HIDDEN Empty ( )
inline

Check if the queue is empty.

◆ Remove()

void IGNITION_GAZEBO_HIDDEN Remove ( RegistrationObjectId  _regObjId)
inline

Remove a component descriptor from the queue. This also deletes memory allocated for the component descriptor by the static component registration object.

Parameters
[in]_regObjIdAn ID that identifies the registration object. This is generally derived from the this pointer of the static component registration object created when calling IGN_GAZEBO_REGISTER_COMPONENT.

References std::find_if(), and std::prev().


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