holoscan::GreedyScheduler

Beta

This is a single-threaded scheduler that will execute operators serially in a deterministic order. Holoscan sorts operators so that execution will occur in topological order (moving from the root to the leaves of the computation graph).

==Parameters==

stop_on_deadlock (bool): If True, the application will terminate if a deadlock state is reached. Defaults to true.
stop_on_deadlock_timeout (int64_t): The amount of time (in ms) before an application is considered to be in deadlock. Defaults to 0.
check_recession_period_ms (double): Duration to sleep before checking the condition of the next operator (default: 0 ms). The units are in ms.
max_duration_ms_ (int64_t, optional): Terminate the application after the specified duration even if deadlock does not occur. If unspecified, the application can run indefinitely.

#include <holoscan/greedy_scheduler.hpp>

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

Constructors

GreedyScheduler

Move

Default

inlineexplicit

template <typename ArgT,
          typename... ArgsT,
          typename = std::enable_if_t<!std::is_base_of_v<::holoscan::Scheduler, 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::GreedyScheduler::GreedyScheduler(holoscan::GreedyScheduler::GreedyScheduler(
    ArgT &&arg,
    ArgsT &&... args
)

Methods

gxf_typename

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

Get the type name of the GXF scheduler.

The returned string is the type name of the GXF scheduler and is used to create the GXF scheduler.

Example: “nvidia::holoscan::GreedyScheduler”

Returns: The type name of the GXF scheduler.

clock

std::shared_ptr<Clock> holoscan::GreedyScheduler::clock() overridestd::shared_ptr<Clock> holoscan::GreedyScheduler::clock() override

Get the Clock used by the scheduler.

Returns: The Clock used by the scheduler.

setup

void holoscan::GreedyScheduler::setup(
    ComponentSpec &spec
) override

Define the scheduler specification.

Parameters

spec

ComponentSpec &

The reference to the component specification.

initialize

void holoscan::GreedyScheduler::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.

stop_on_deadlock

bool holoscan::GreedyScheduler::stop_on_deadlock() const

check_recession_period_ms

double holoscan::GreedyScheduler::check_recession_period_ms() const

stop_on_deadlock_timeout

int64_t holoscan::GreedyScheduler::stop_on_deadlock_timeout() const

network_connection_timeout

int64_t holoscan::GreedyScheduler::network_connection_timeout() const

max_duration_ms

int64_t holoscan::GreedyScheduler::max_duration_ms() const

get

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

gxf_clock

virtual nvidia::gxf::Clock * holoscan::GreedyScheduler::gxf_clock()

Get the GXF Clock pointer.

Returns: The GXF clock pointer used by the scheduler.

to_yaml_node

YAML::Node holoscan::GreedyScheduler::to_yaml_node() const override

Get a YAML representation of the scheduler.

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

reset_backend_objects

void holoscan::GreedyScheduler::reset_backend_objects() override

Reset any backend-specific objects.

set_parameters

void holoscan::GreedyScheduler::set_parameters() override

Set the parameters based on defaults (sets GXF parameters for GXF operators).

id

Mutable

Const

Scheduler & holoscan::Scheduler::id(Scheduler & holoscan::Scheduler::id(
    int64_t id
)

Set the Scheduler ID.

Returns: The reference to this scheduler.

Parameters

int64_t

The ID of the scheduler.

name

Set the name of the scheduler (1)

Set the name of the scheduler (2)

Const

Scheduler & holoscan::Scheduler::name(Scheduler & holoscan::Scheduler::name(
    const std::string &name
) &

Set the name of the scheduler.

Returns: The reference to the scheduler.

Parameters

name

const std::string &

The name of the scheduler.

fragment

Set the fragment of the scheduler

Get a pointer to Fragment object

Const

Scheduler & holoscan::Scheduler::fragment(Scheduler & holoscan::Scheduler::fragment(
    Fragment *fragment
)

Set the fragment of the scheduler.

Returns: The reference to the scheduler.

Parameters

fragment

Fragment *

The pointer to the fragment of the scheduler.

spec

Set the component specification to the scheduler

Get the component specification of the scheduler

Scheduler & holoscan::Scheduler::spec(Scheduler & holoscan::Scheduler::spec(
    const std::shared_ptr<ComponentSpec> &spec
)

Set the component specification to the scheduler.

Returns: The reference to the scheduler.

Parameters

spec

const std::shared_ptr<ComponentSpec> &

The component specification.

spec_shared

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

Get the shared pointer to the component spec.

Returns: The shared pointer to the component spec.

add_arg

Add a resource to the scheduler (1)

Add a resource to the scheduler (2)

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::Scheduler::add_arg(
    const std::shared_ptr<Resource> &arg
)

Add a resource to the scheduler.

Parameters

arg

const std::shared_ptr<Resource> &

The resource to add.

resources

std::unordered_map<std::string, std::shared_ptr<Resource>> & holoscan::Scheduler::resources()

Get the resources of the scheduler.

Returns: The resources of the scheduler.

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

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.

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()

clock_gxf_cptr

void * holoscan::GreedyScheduler::clock_gxf_cptr() const override

update_params_from_args

Update parameters based on the specified arguments

Update parameters based on the specified arguments (with params)

void holoscan::Component::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()

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()

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

Template parameters

typeT

typename

The type of the argument to register.

Member variables

Name	Type	Description
`clock_`	`Parameter< std::shared_ptr< gxf::Clock > >`
`stop_on_deadlock_`	`Parameter< bool >`
`max_duration_ms_`	`Parameter< int64_t >`
`check_recession_period_ms_`	`Parameter< double >`
`stop_on_deadlock_timeout_`	`Parameter< int64_t >`
`network_connection_timeout_`	`Parameter< int64_t >`
`resources_`	`std::unordered_map< std::string, std::shared_ptr< Resource > >`	The resources used by the scheduler.
`spec_`	`std::shared_ptr< ComponentSpec >`	The component specification.
`id_`	`int64_t`	The ID of the component.
`name_`	`std::string`	Name 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 *`