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On this page
  • Constructors
  • SyntheticClock
  • Methods
  • gxf_typename
  • setup
  • time
  • timestamp
  • sleep_for
  • sleep_until
  • advance_to
  • advance_by
  • get
  • initialize
  • resource_type
  • name
  • fragment
  • spec
  • spec_shared
  • id
  • add_arg
  • args
  • description
  • service
  • get_service_by_type_info
  • gxf_context
  • gxf_eid
  • gxf_tid
  • gxf_cid
  • gxf_cname
  • gxf_graph_entity
  • gxf_entity_group_name
  • gxf_entity_group_id
  • gxf_cptr
  • gxf_component
  • gxf_initialize
  • set_gxf_parameter
  • reset_gxf_graph_entity
  • add_to_graph_entity
  • to_yaml_node
  • set_parameters
  • handle_dev_id
  • reset_backend_objects
  • update_params_from_args
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  • Static methods
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API referenceC++ APIHoloscanClasses

holoscan::SyntheticClock

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holoscan::SystemResourceManager

Synthetic clock class.

A clock where time flow is synthesized, like from a recording or a simulation.

==Parameters==

  • initial_timestamp (int64_t): The initial timestamp on the clock (in nanoseconds) (default: 0.0).
#include <holoscan/synthetic_clock.hpp>

Inherits from: holoscan::gxf::Clock (public)


Constructors

SyntheticClock

Move
Default
Copy
inlineexplicit
template <typename ArgT,
typename... ArgsT,
typename = std::enable_if_t<!std::is_base_of_v<::holoscan::Resource, std::decay_t<ArgT>> && (std::is_same_v<::holoscan::Arg, std::decay_t<ArgT>> || std::is_same_v<::holoscan::ArgList, std::decay_t<ArgT>>)>>
holoscan::SyntheticClock::SyntheticClock(holoscan::SyntheticClock::SyntheticClock(
ArgT &&arg,
ArgsT &&... args
)

Methods

gxf_typename

const char * holoscan::SyntheticClock::gxf_typename() const override

The underlying GXF component’s name.

setup

void holoscan::SyntheticClock::setup(
ComponentSpec &spec
)

Define the resource specification.

Parameters

spec
ComponentSpec &

The reference to the component specification.

time

double holoscan::SyntheticClock::time() const override

The current time of the clock. Time is measured in seconds.

timestamp

int64_t holoscan::SyntheticClock::timestamp() const override

The current timestamp of the clock. Timestamps are measured in nanoseconds.

sleep_for

Overload 1
Set a duration to sleep
virtual
void holoscan::SyntheticClock::sleep_for(
int64_t duration_ns
) override

Waits until the given duration has elapsed on the clock.

sleep_until

void holoscan::SyntheticClock::sleep_until(
int64_t target_time_ns
) override

Waits until the given target time.

advance_to

void holoscan::SyntheticClock::advance_to(
int64_t new_time_ns
)

Manually advance the clock to a desired new target time.

advance_by

Manually advance the clock by a given delta
Set a duration to advance the clock by
void holoscan::SyntheticClock::advance_by(
int64_t time_delta_ns
)

Manually advance the clock by a given delta.

get

nvidia::gxf::SyntheticClock * holoscan::SyntheticClock::get() constnvidia::gxf::SyntheticClock * holoscan::SyntheticClock::get() const

initialize

void holoscan::gxf::GXFResource::initialize() override

Initialize the component.

This method is called only once when the component is created for the first time, and use of light-weight initialization.

resource_type

ResourceType holoscan::Resource::resource_type() const

Get the resource type.

Returns: The resource type.

name

Set the name of the resource (1)
Set the name of the resource (2)
Const
Resource & holoscan::Resource::name(Resource & holoscan::Resource::name(
const std::string &name
) &

Set the name of the resource.

Returns: The reference to the resource.

Parameters

name
const std::string &

The name of the resource.

fragment

Set the fragment of the resource

Get a pointer to Fragment object

Const
Resource & holoscan::Resource::fragment(Resource & holoscan::Resource::fragment(
Fragment *fragment
)

Set the fragment of the resource.

Returns: The reference to the resource.

Parameters

fragment
Fragment *

The pointer to the fragment of the resource.

spec

Set the component specification to the resource
Get the component specification of the resource
Resource & holoscan::Resource::spec(Resource & holoscan::Resource::spec(
const std::shared_ptr<ComponentSpec> &spec
)

Set the component specification to the resource.

Returns: The reference to the resource.

Parameters

spec
const std::shared_ptr<ComponentSpec> &

The component specification.

spec_shared

std::shared_ptr<ComponentSpec> holoscan::Resource::spec_shared()

Get the shared pointer to the component spec.

Returns: The shared pointer to the component spec.

id

int64_t holoscan::ComponentBase::id() const

Get the identifier of the component.

By default, the identifier is set to -1. It is set to a valid value when the component is initialized.

With the default executor (GXFExecutor), the identifier is set to the GXF component ID.

Returns: The identifier of the component.

add_arg

Add an argument to the component (1)
Add an argument to the component (2)
Add a list of arguments to the component (1)
Add a list of arguments to the component (2)
void holoscan::ComponentBase::add_arg(
const Arg &arg
)

Add an argument to the component.

Parameters

arg
const Arg &

The argument to add.

args

std::vector<Arg> & holoscan::ComponentBase::args()

Get the list of arguments.

Returns: The vector of arguments.

description

std::string holoscan::ComponentBase::description() const

Get a description of the component.

Returns: YAML string.

See also: to_yaml_node()

service

template <typename ServiceT = DefaultFragmentService>
std::shared_ptr<ServiceT> holoscan::ComponentBase::service(
std::string_view id = ""
) const

Retrieve a registered fragment service or resource.

Retrieves a previously registered fragment service or resource by its type and optional identifier. Returns nullptr if no service/resource is found with the specified type and identifier.

Note that any changes to the service retrieval logic in this method should be synchronized with the implementation in Fragment::service() method to maintain consistency.

Returns: The shared pointer to the service/resource, or nullptr if not found or if type casting fails.

Template parameters

ServiceT
typename

The type of the service/resource to retrieve. Must inherit from either Resource or FragmentService. Defaults to DefaultFragmentService if not specified.

Parameters

id
std::string_viewDefaults to ""

The identifier of the service/resource. If empty, retrieves by type only.

get_service_by_type_info

std::shared_ptr<FragmentService> holoscan::ComponentBase::get_service_by_type_info(
const std::type_info &service_type,
std::string_view id = ""
) const

Retrieve a registered fragment service or resource for Python bindings.

This is a helper method for Python bindings to retrieve a service by its C++ type info.

Returns: The shared pointer to the base service, or nullptr if not found.

Parameters

service_type
const std::type_info &

The type info of the service/resource to retrieve.

id
std::string_viewDefaults to ""

The identifier of the service/resource. If empty, retrieves by type only.

gxf_context

Mutable
Const
void holoscan::gxf::GXFComponent::gxf_context(
gxf_context_t gxf_context
)

gxf_eid

Mutable
Const
void holoscan::gxf::GXFComponent::gxf_eid(
gxf_uid_t gxf_eid
)

gxf_tid

Mutable
Const
void holoscan::gxf::GXFComponent::gxf_tid(
gxf_tid_t gxf_tid
)

gxf_cid

Mutable
Const
void holoscan::gxf::GXFComponent::gxf_cid(
gxf_uid_t gxf_cid
)

gxf_cname

Overload 1
Overload 2
std::string & holoscan::gxf::GXFComponent::gxf_cname()

gxf_graph_entity

Overload 1
Overload 2
std::shared_ptr<nvidia::gxf::GraphEntity> holoscan::gxf::GXFComponent::gxf_graph_entity()

gxf_entity_group_name

std::string holoscan::gxf::GXFComponent::gxf_entity_group_name()

The name of the entity group this component belongs to.

gxf_entity_group_id

gxf_uid_t holoscan::gxf::GXFComponent::gxf_entity_group_id()

The group id of the entity group this component belongs to.

gxf_cptr

void * holoscan::gxf::GXFComponent::gxf_cptr()

gxf_component

nvidia::gxf::Handle<nvidia::gxf::Component> holoscan::gxf::GXFComponent::gxf_component()

gxf_initialize

void holoscan::gxf::GXFComponent::gxf_initialize()

set_gxf_parameter

void holoscan::gxf::GXFComponent::set_gxf_parameter(
const std::string &component_name,
const std::string &key,
ParameterWrapper &param_wrap
)

Set a given parameter on the underlying GXF component.

reset_gxf_graph_entity

void holoscan::gxf::GXFComponent::reset_gxf_graph_entity()

add_to_graph_entity

Overload 1
Overload 2
virtual
virtual void holoscan::gxf::GXFResource::add_to_graph_entity(
Operator *op
)

to_yaml_node

YAML::Node holoscan::gxf::GXFResource::to_yaml_node() const override

Get a YAML representation of the resource.

Returns: YAML node including type and specs of the resource in addition to the base component properties.

set_parameters

void holoscan::gxf::GXFResource::set_parameters() override

This method is invoked by GXFResource::initialize().

By overriding this method, we can modify how GXF Codelet’s parameters are set from the arguments.

handle_dev_id

bool holoscan::gxf::GXFResource::handle_dev_id(
std::optional<int32_t> &dev_id_value
)

reset_backend_objects

void holoscan::gxf::GXFResource::reset_backend_objects() override

Reset any backend-specific state.

update_params_from_args

Update parameters based on the specified arguments
Update parameters based on the specified arguments (with params)
void holoscan::Resource::update_params_from_args()

Update parameters based on the specified arguments.

service_provider

void holoscan::ComponentBase::service_provider(
FragmentServiceProvider *provider
)

Set the service provider that owns this component.


Static methods

register_converter

template <typename typeT>
static void holoscan::ComponentBase::register_converter()

Register the argument setter for the given type.

If an operator or resource has an argument with a custom type, the argument setter must be registered using this method.

The argument setter is used to set the value of the argument from the YAML configuration.

This method can be called in the initialization phase of the operator/resource (e.g., initialize()). The example below shows how to register the argument setter for the custom type (Vec3):

It is assumed that YAML::convert<T>::encode and YAML::convert<T>::decode are implemented for the given type. You need to specialize the YAML::convert<> template class.

For example, suppose that you had a Vec3 class with the following members:

You can define the YAML::convert<Vec3> as follows in a ‘.cpp’ file:

Please refer to the yaml-cpp documentation for more details.

Template parameters

typeT
typename

The type of the argument to register.

Example

void MyOp::initialize() {
register_converter<Vec3>();
}

Example

struct Vec3 {
// make sure you have overloaded operator==() for the comparison
double x, y, z;
};

Example

namespace YAML {
template<>
struct convert<Vec3> {
static Node encode(const Vec3& rhs) {
Node node;
node.push_back(rhs.x);
node.push_back(rhs.y);
node.push_back(rhs.z);
return node;
}
static bool decode(const Node& node, Vec3& rhs) {
if(!node.IsSequence() || node.size() != 3) {
return false;
}
rhs.x = node[0].as<double>();
rhs.y = node[1].as<double>();
rhs.z = node[2].as<double>();
return true;
}
};
}

register_argument_setter

template <typename typeT>
void holoscan::ComponentBase::register_argument_setter()

Register the argument setter for the given type.

Please refer to the documentation of register_converter() for more details.

Template parameters

typeT
typename

The type of the argument to register.


Types

ResourceType

Resource type used for the initialization of the resource.

NameValueDescription
kNativeNative resource.
kGXFGXF resource.

Member variables

NameTypeDescription
initial_timestamp_Parameter< int64_t >
gxf_typename_std::stringThe GXF type name (used for GXFComponentResource).
resource_type_ResourceTypeThe type of the resource.
is_initialized_boolWhether the resource is initialized.
spec_std::shared_ptr< ComponentSpec >The component specification.
id_int64_tThe ID of the component.
name_std::stringName of the component.
fragment_Fragment *Pointer to the fragment that owns this component.
args_std::vector< Arg >List of arguments.
service_provider_FragmentServiceProvider *Pointer to the service provider.
gxf_context_gxf_context_t
gxf_eid_gxf_uid_t
gxf_tid_gxf_tid_t
gxf_cid_gxf_uid_t
gxf_graph_entity_std::shared_ptr< nvidia::gxf::GraphEntity >
gxf_cname_std::string
gxf_component_nvidia::gxf::Handle< nvidia::gxf::Component >
gxf_cptr_void *