[source]

Class uvm_pkg::uvm_callbacks

uvm_pkg::uvm_callbacks <T, CB> + m_base_inst : uvm_callbacks #(T, uvm_callback) + m_cb_typeid : uvm_typeid_base + m_cb_typename : string + m_registered : bit + m_typeid : uvm_typeid_base + m_typename : string + reporter : uvm_report_object + add(): void + add_by_name(): void + delete(): void + delete_by_name(): void + display(): void + get(): this_type + get_first(): CB + get_last(): CB + get_next(): CB + get_prev(): CB + m_get_q(): void + m_is_for_me(): bit + m_is_registered(): bit + m_register_pair(): bit uvm_pkg::uvm_derived_callbacks <T, ST, CB> <T : T, CB : CB>

Inheritance Diagram of uvm_callbacks

uvm_pkg::uvm_callbacks <T, CB> + m_base_inst : uvm_callbacks #(T, uvm_callback) + m_cb_typeid : uvm_typeid_base + m_cb_typename : string + m_registered : bit + m_typeid : uvm_typeid_base + m_typename : string + reporter : uvm_report_object + add(): void + add_by_name(): void + delete(): void + delete_by_name(): void + display(): void + get(): this_type + get_first(): CB + get_last(): CB + get_next(): CB + get_prev(): CB + m_get_q(): void + m_is_for_me(): bit + m_is_registered(): bit + m_register_pair(): bit uvm_pkg::uvm_typeid_base uvm_pkg::uvm_report_object m_typeid m_cb_typeid reporter m_base_inst

Collaboration Diagram of uvm_callbacks

CLASS

uvm_callbacks #(T,CB)

The uvm_callbacks class provides a base class for implementing callbacks, which are typically used to modify or augment component behavior without changing the component class. To work effectively, the developer of the component class defines a set of "hook" methods that enable users to customize certain behaviors of the component in a manner that is controlled by the component developer. The integrity of the component's overall behavior is intact, while still allowing certain customizable actions by the user.

To enable compile-time type-safety, the class is parameterized on both the user-defined callback interface implementation as well as the object type associated with the callback. The object type-callback type pair are associated together using the [`uvm_register_cb](../../../../index-macros.html#macros) macro to define a valid pairing; valid pairings are checked when a user attempts to add a callback to an object.

To provide the most flexibility for end-user customization and reuse, it is recommended that the component developer also define a corresponding set of virtual method hooks in the component itself. This affords users the ability to customize via inheritance/factory overrides as well as callback object registration. The implementation of each virtual method would provide the default traversal algorithm for the particular callback being called. Being virtual, users can define subtypes that override the default algorithm, perform tasks before and/or after calling super. to execute any registered callbacks, or to not call the base implementation, effectively disabling that particular hook. A demonstration of this methodology is provided in an example included in the kit.

Parameters

Name

Default value

Description
T

uvm_object
CB

uvm_callback
Variables

Name

Type

Description
reporter

uvm_report_object
Typedefs

Name

Actual Type

Description
super_type

uvm_typed_callbacks#(T)

Parameter

CB

This type parameter specifies the base callback type that will be managed by this callback class. The callback type is typically a interface class, which defines one or more virtual method prototypes that users can override in subtypes. This type must be a derivative of uvm_callback.
this_type

uvm_callbacks#(T, CB)

Functions

get()

get

Return type:

this_type

add(uvm_object obj, uvm_callback cb, uvm_apprepend ordering = UVM_APPEND)

Function

add

Registers the given callback object, cb , with the given obj handle. The obj handle can be null , which allows registration of callbacks without an object context. If ordering is UVM_APPEND (default), the callback will be executed after previously added callbacks, else the callback will be executed ahead of previously added callbacks. The cb is the callback handle; it must be non- null , and if the callback has already been added to the object instance then a warning is issued. Note that the CB parameter is optional. For example, the following are equivalent:

 uvm_callbacks#(my_comp)::add(comp_a, cb);
 uvm_callbacks#(my_comp, my_callback)::add(comp_a,cb);
Parameters:
add_by_name(string name, uvm_callback cb, uvm_component root, uvm_apprepend ordering = UVM_APPEND)

Function

add_by_name

Registers the given callback object, cb , with one or more uvm_components. The components must already exist and must be type T or a derivative. As with add the CB parameter is optional. root specifies the location in the component hierarchy to start the search for name . See uvm_root::find_all for more details on searching by name.

Parameters:
delete(uvm_object obj, uvm_callback cb)

Function

delete

Deletes the given callback object, cb , from the queue associated with the given obj handle. The obj handle can be null , which allows de-registration of callbacks without an object context. The cb is the callback handle; it must be non- null , and if the callback has already been removed from the object instance then a warning is issued. Note that the CB parameter is optional. For example, the following are equivalent:

 uvm_callbacks#(my_comp)::delete(comp_a, cb);
 uvm_callbacks#(my_comp, my_callback)::delete(comp_a,cb);
Parameters:
delete_by_name(string name, uvm_callback cb, uvm_component root)

Function

delete_by_name

Removes the given callback object, cb , associated with one or more uvm_component callback queues. As with delete the CB parameter is optional. root specifies the location in the component hierarchy to start the search for name . See uvm_root::find_all for more details on searching by name.

Parameters:
get_first(int itr, uvm_object obj)

Function

get_first

Returns the first enabled callback of type CB which resides in the queue for obj . If obj is null then the typewide queue for T is searched. itr is the iterator; it will be updated with a value that can be supplied to get_next to get the next callback object.

If the queue is empty then null is returned.

The iterator class uvm_callback_iter may be used as an alternative, simplified, iterator interface.

Parameters:
Return type:

CB

get_last(int itr, uvm_object obj)

Function

get_last

Returns the last enabled callback of type CB which resides in the queue for obj . If obj is null then the typewide queue for T is searched. itr is the iterator; it will be updated with a value that can be supplied to get_prev to get the previous callback object.

If the queue is empty then null is returned.

The iterator class uvm_callback_iter may be used as an alternative, simplified, iterator interface.

Parameters:
Return type:

CB

get_next(int itr, uvm_object obj)

Function

get_next

Returns the next enabled callback of type CB which resides in the queue for obj , using itr as the starting point. If obj is null then the typewide queue for T is searched. itr is the iterator; it will be updated with a value that can be supplied to get_next to get the next callback object.

If no more callbacks exist in the queue, then null is returned. get_next will continue to return null in this case until get_first or get_last has been used to reset the iterator.

The iterator class uvm_callback_iter may be used as an alternative, simplified, iterator interface.

Parameters:
Return type:

CB

get_prev(int itr, uvm_object obj)

Function

get_prev

Returns the previous enabled callback of type CB which resides in the queue for obj , using itr as the starting point. If obj is null then the typewide queue for T is searched. itr is the iterator; it will be updated with a value that can be supplied to get_prev to get the previous callback object.

If no more callbacks exist in the queue, then null is returned. get_prev will continue to return null in this case until get_first or get_last has been used to reset the iterator.

The iterator class uvm_callback_iter may be used as an alternative, simplified, iterator interface.

Parameters:
Return type:

CB

display(uvm_object obj = null)

Function

display

This function displays callback information for obj . If obj is null , then it displays callback information for all objects of type T , including typewide callbacks.

Parameters:

obj (uvm_object)