fuchsia.sys2

PROTOCOLS

Realm

Defined in fuchsia.sys2/realm.fidl

A protocol used by a component instance to manage its own realm, such as for binding to its children.

The component manager provides this service to components that use /svc/fuchsia.sys2.Realm.

BindChild

Binds to a child component instance, causing it to start running if it is not already. When this function successfully returns, child is running and exposed_dir is bound to a directory that contains the capabilities which the child exposed to its realm via ComponentDecl.exposes (specified via "expose" declarations in the component’s manifest).

exposed_dir is a valid channel as long as child is running. child will remain running until it either stops on its own, or DestroyChild causes the child instance to be destroyed.

For example, if the child exposes a service /svc/example.Echo then exposed_dir will contain that service at that path.

NOTE: BindChild does not support pipelining with CreateChild. If BindChild is called on an instance before CreateChild successfully returns, it may return INSTANCE_NOT_FOUND.

Errors:

• INVALID_ARGUMENTS: child is not a valid child reference. -
• INSTANCE_NOT_FOUND: child does not exist.
• INSTANCE_CANNOT_START: child was not running and there was an error starting it.
• INSTANCE_CANNOT_RESOLVE: child's component declaration failed to resolve.

Request

Name	Type
child	ChildRef
exposed_dir	request<fuchsia.io/Directory>

Response

Name	Type
result	Realm_BindChild_Result

CreateChild

Creates a child component instance dynamically. When this function returns successfully, the instance exists, but it may not be running.

Errors:

• INVALID_ARGUMENTS: collection is not a valid reference or child is not a valid declaration.
• COLLECTION_NOT_FOUND: collection does not exist.
• INSTANCE_ALREADY_EXISTS: decl.name already exists in collection.
• NO_SPACE: Could not allocate storage for the new instance.

Request

Name	Type
collection	CollectionRef
decl	ChildDecl

Response

Name	Type
result	Realm_CreateChild_Result

DestroyChild

Destroys a dynamically-created component instance. When this function returns, the client should assume the instance no longer exists. However, some cleanup (such as stopping the component instance or freeing its storage) may be performed in the background after the function returns.

Errors:

• INVALID_ARGUMENTS: child is not a valid reference or does not refer to a dynamic instance.
• INSTANCE_NOT_FOUND: child does not exist.
• COLLECTION_NOT_FOUND: collection does not exist.

Request

Name	Type
child	ChildRef

Response

Name	Type
result	Realm_DestroyChild_Result

ListChildren

Returns an iterator that lists all instances in a collection.

NOTE: The results are not guaranteed to be consistent. Instances may be created or destroyed while the iterator is live, but those changes won't be observed by the iterator after this method returns.

Errors:

• INVALID_ARGUMENTS: collection is not a valid reference.
• COLLECTION_NOT_FOUND: collection does not exist.

Request

Name	Type
collection	CollectionRef
iter	request<ChildIterator>

Response

Name	Type
result	Realm_ListChildren_Result

ChildIterator

Defined in fuchsia.sys2/realm.fidl

A protocol to iterate over the list of children in a realm.

Next

Advance the iterator and return the next batch of children.

Returns a vector of ChildRef. Returns an empty vector when there are no more children.

Request

Name	Type

Response

Name	Type
children	vector<ChildRef>

ComponentResolver

Defined in fuchsia.sys2/component_resolver.fidl

An interface for resolving a URL to a component.

This interface is implemented by components that provide support for loading components with a particular URL scheme. For example, the Fuchsia package component resolver exposes a service with this interface to resolve component URLs using the "fuchsia-pkg://" scheme.

To use a resolver to resolve URLs within your realm, register it in your realm's manifest. (TODO: explain in more detail)

Note: The component manager is the only intended direct client of this interface.

Resolve

Resolves a component with the given URL.

component_url is the unescaped URL of the component to resolve.

If successful, returns ZX_OK and information about the component that was resolved.

On failure, returns null info and...

• ZX_ERR_INVALID_ARGS: The component's URL was malformed.
• ZX_ERR_NOT_FOUND: The component does not exist.
• ZX_ERR_UNAVAILABLE: The resolver was unable to retrieve or parse the component's resources.

Request

Name	Type
component_url	string

Response

Name	Type
status	zx/status
component	Component

SystemController

Defined in fuchsia.sys2/system_controller.fidl

An interface implemented by ComponentManager that requests the ComponentManager stop all components and exit.

Shutdown

Stop all components, return an empty result, close this protocol's channel, and exit ComponentManager. If this is the root ComponentManager is exited we expect the system will reboot.

Request

Name	Type

Response

Name	Type

WorkScheduler

Defined in fuchsia.sys2/work_scheduler.fidl

Framework service: API for scheduling and canceling work. Each component instance can access work items that it has scheduled (but not others' scheduled work items). Work items are scheduled roughly at the specified time and frequency; the service implementation may specify its notion of roughly, and may provide a configuration API to tune this notion.

Each scheduled work item is identified by a client-provided WorkId. Each scheduled work item has a WorkId that is unique with respect to scheduled work items belonging to the same component instance.

ScheduleWork

Schedule a new work item identified by work_id. The work item is to be scheduled roughly at the time corresponding to work_request.start. When work_request.period is specified, reschedule work roughly every work_request.period until the the work item is canceled.

Request

Name	Type
work_id	WorkId
work_request	WorkRequest

Response

Name	Type
result	WorkScheduler_ScheduleWork_Result

CancelWork

Cancel the scheduled work item specified by work_id.

Request

Name	Type
work_id	WorkId

Response

Name	Type
result	WorkScheduler_CancelWork_Result

Worker

Defined in fuchsia.sys2/work_scheduler.fidl

Component-exposed service: Work scheduler connects to this service to invoke scheduled work item callbacks. The service implementation is responsible for invoking the code that corresponds to the scheduled work item identified by work_id.

Note: The intent of exposing this service is to expose it to the WorkScheduler service provider (i.e., the framework) and no one else.

DoWork

Request

Name	Type
work_id	WorkId

Response

Name	Type
result	Worker_DoWork_Result

WorkSchedulerControl

Defined in fuchsia.sys2/work_scheduler.fidl

Framework service: Administrative API for controlling parameters of the WorkScheduler framework service. So long as there are work items with deadlines in the next batch_period, the WorkScheduler will sleep for batch_period, then wake up and immediately dispatch a batch of work items: all those with past deadlines. It will repeat this process until no work items would be scheduled in the next batch_period, at which point it will go to sleep until the next deadline. This strategy ensures that each work item is dispatched approximately within batch_period of its deadline.

GetBatchPeriod

Get the current period between WorkScheduler attempts to dispatch a batch of work. batch_period is a non-negative 64-bit integer in the range [0, 2^63-1], representing a number of nanoseconds between dispatching batches of work.

Request

Name	Type

Response

Name	Type
result	WorkSchedulerControl_GetBatchPeriod_Result

SetBatchPeriod

Set the current period between WorkScheduler attempts to batch and dispatch a batch of work. batch_period is a non-negative 64-bit integer in the range [0, 2^63-1], representing a number of nanoseconds between dispatching batches of work.

Request

Name	Type
batch_period	zx/duration

Response

Name	Type
result	WorkSchedulerControl_SetBatchPeriod_Result

STRUCTS

Vector

Defined in fuchsia.sys2/object.fidl

A vector is a sequence of values.

Name	Type	Description	Default
values	vector<Value>		No default

Object

Defined in fuchsia.sys2/object.fidl

An object is a sequence of key/value pairs. Keys must be unique and sorted in lexicographically increasing order.

Name	Type	Description	Default
entries	vector<Entry>		No default

Entry

Defined in fuchsia.sys2/object.fidl

A key/value pair in an Object.

Name	Type	Description	Default
key	string		No default
value	Value?		No default

RealmRef

Defined in fuchsia.sys2/relative_refs.fidl

A reference to a component’s containing realm, i.e. the parent component.

Name	Type	Description	Default

SelfRef

Defined in fuchsia.sys2/relative_refs.fidl

A reference to the component itself.

Name	Type	Description	Default

ChildRef

Defined in fuchsia.sys2/relative_refs.fidl

A reference to one of the component's child instances.

Name	Type	Description	Default
name	fuchsia.component/child_name	The name assigned to the child by its parent. If collection is set, name is scoped to collection and the child is a dynamic instance. Required.	No default
collection	fuchsia.component/collection_name	The collection name belongs to. If omitted, name references a static instance. This field must be omitted if the ChildRef is being used in a component declaration. Optional.	No default

CollectionRef

Defined in fuchsia.sys2/relative_refs.fidl

A reference to one of the component's collections.

Name	Type	Description	Default
name	fuchsia.component/collection_name		No default

StorageRef

Defined in fuchsia.sys2/relative_refs.fidl

A reference to one of the component's storage sections.

Name	Type	Description	Default
name	string[100]		No default

FrameworkRef

Defined in fuchsia.sys2/relative_refs.fidl

A reference to the component framework itself.

Name	Type	Description	Default

Realm_BindChild_Response

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description	Default

Realm_CreateChild_Response

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description	Default

Realm_DestroyChild_Response

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description	Default

Realm_ListChildren_Response

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description	Default

WorkScheduler_ScheduleWork_Response

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description	Default

WorkScheduler_CancelWork_Response

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description	Default

Worker_DoWork_Response

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description	Default

WorkSchedulerControl_GetBatchPeriod_Response

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description	Default
batch_period	zx/duration		No default

WorkSchedulerControl_SetBatchPeriod_Response

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description	Default

ENUMS

StartupMode

Type: uint32

Defined in fuchsia.sys2/child_decl.fidl

Describes under what conditions the component may be started.

Name	Value	Description
LAZY	0	Start component instance only when another instance binds to it.
EAGER	1	Start component instance as soon as parent starts. This mode is only supported for statically declared children -- a dynamic instance may only be started by binding to it.

Durability

Type: uint32

Defined in fuchsia.sys2/collection_decl.fidl

The durability of component instances created in a collection.

Name	Value	Description
PERSISTENT	1	An instance exists until either it or its parent is destroyed.
TRANSIENT	2	An instance exists until either its parent instance is stopped or it is explicitly destroyed.

EnvironmentExtends

Type: uint32

Defined in fuchsia.sys2/environment_decl.fidl

Specifies how a declared environment's initial set of properties are assigned.

Name	Value	Description
NONE	0	The environment has no initial set of properties.
REALM	1	The environment's initial set of properties are inherited from its realm. Inherited properties include any fields defined in EnvironmentDecl.

DependencyType

Type: uint32

Defined in fuchsia.sys2/offer_decl.fidl

Describes the type of dependency implied by the capability.

Name	Value	Description
STRONG	1	A strong dependency which may be required by components that use it.
WEAK_FOR_MIGRATION	2	A weak dependency specifically used to mark cyclic dependencies of migrated components. Components that use a weak dependency must support the dependency being unavailable at arbitrary times.

StorageType

Type: uint32

Defined in fuchsia.sys2/storage_decl.fidl

The type of storage offered by this component.

Name	Value	Description
DATA	1	General data storage.
CACHE	2	Cache storage that may be deleted at any time by the system.
META	3	Meta storage that will be used by component manager to persist metadata and other information about the component

TABLES

ChildDecl

Defined in fuchsia.sys2/child_decl.fidl

Statically declares a child component instance.

Ordinal	Name	Type	Description
1	name	fuchsia.component/child_name	The name assigned to the child by its parent. Must be non-empty, unique among all siblings, and contain only the following characters: [a-z0-9-_.].
2	url	fuchsia.url/Url	The child component's URL. Must be non-empty and a well-formed URL.
3	startup	StartupMode	The startup mode for the component instance.
4	environment	fuchsia.component/environment_name	The environment assigned to the child. This environment will be used when resolving the child's url. Must be non-empty, reference an environment defined in the containing ComponentDecl, and contain only the following characters: [a-z0-9-_.].

CollectionDecl

Defined in fuchsia.sys2/collection_decl.fidl

Statically declares a component instance collection.

Ordinal	Name	Type	Description
1	name	fuchsia.component/collection_name	The name of the collection. Instances created in the collection are scoped to this name.
2	durability	Durability	The durability of instances in the collection.

ComponentDecl

Defined in fuchsia.sys2/component_decl.fidl

A component declaration.

This information is typically encoded in the component manifest (.cm file) if it has one or may be generated at runtime by a component resolver for those that don't.

Ordinal	Name	Type	Description
1	program	fuchsia.data/Dictionary	Information about the program to run when the component is executed. The component manager provides the contents of this dictionary to the component runner when executing the program. Each component runner can freely define the contents of this dictionary as needed. The system's default runner understands the following entries: "binary": string The path of the executable relative to the root of the package. Typically an ELF binary. "args": vector of strings The command-line arguments to provide to the executable at runtime. "env": dictionary of strings The environment variables to provide to the executable at runtime. Other runners may define different entries.
2	uses	vector<UseDecl>	List of capabilities used by the component. These consist of capabilities offered to the component that are installed in its incoming namespace. The used capabilities must be unique and non-overlapping.
3	exposes	vector<ExposeDecl>	List of capabilities exposed by the component. These consist of capabilities that are made visible to the containing realm. The parent may offer these capabilities to its children, but not use them. The exposed capabilities must be unique and non-overlapping.
4	offers	vector<OfferDecl>	List of capabilities offered to the component’s children. These consist of capabilities that the given children may use, which may come from a child, the containing realm, or the component's own outgoing namespace. The offered capabilities must be unique and non-overlapping.
5	facets	Object	Additional metadata about the component.
6	children	vector<ChildDecl>	The component's statically instantiated children. The children must have unique names.
7	collections	vector<CollectionDecl>	The component's collections. The collections must have unique names.
8	storage	vector<StorageDecl>	List of storage capabilities created by this component. Storage capabilities can be offered to children.
9	runners	vector<RunnerDecl>	List of runner capabilities created by this component. Runner capabilities can be exposed to the parent's realm or offered to children.
10	environments	vector<EnvironmentDecl>	List of environments created by this component. Environments are assigned to children and control aspects of a child component's runtime.
11	resolvers	vector<ResolverDecl>	List of resolver capabilities created by this component. A component can: "expose" a resolver capability to its realm, "offer" a resolver capability to its children, register a resolver in an environment. A component cannot "use" a resolver capability directly. Component manager uses a resolver capability on behalf of a component when that component's environment contains the resolver capability.

EnvironmentDecl

Defined in fuchsia.sys2/environment_decl.fidl

Declares an environment which configures a realm.

Ordinal	Name	Type	Description
1	name	fuchsia.component/environment_name	The name of this environment.
2	extends	EnvironmentExtends	Specifies how the initial state of this environment is constructed.
3	resolvers	vector<ResolverRegistration>	List of component resolvers and the URL schemes they are registered to resolve. These registrations determine how components are resolved in the realm. If the component URL scheme does not match any of these resolvers, URL resolution is delegated to the parent environment, if this environment extends from REALM.
4	stop_timeout_ms	uint32	The duration in milliseconds that the component will have to stop before it is killed.

ResolverRegistration

Defined in fuchsia.sys2/environment_decl.fidl

A mapping of URL scheme to resolver name.

Ordinal	Name	Type	Description
1	resolver	fuchsia.component/resolver_name	The name of the resolver.
2	source	Ref	The provider of the capability relative to the component itself. Must be realm, self, or child.
3	scheme	fuchsia.component/url_scheme	The URL scheme the resolver is registered to handle. Only one resolver may be registered to a particular URL scheme. The URL scheme must start with a lowercase ASCII letter (a-z), and may contain lowercase ASCII letters, digits, +, -, and ..

ExposeServiceDecl

Defined in fuchsia.sys2/expose_decl.fidl

Declares a service exposed to a component's containing realm, such as a service exposed by the component or one of its children at runtime.

To learn more about services, see: https://fuchsia.dev/fuchsia-src/glossary#service

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be self or child.
2	source_path	string[1024]	Path identifying the service, by which it was presented to this component. Must be an absolute path starting with /.
3	target	Ref	The destination to which the service is exposed: either the component's realm or the framework.
4	target_path	string[1024]	The path by which the capability is being exposed. Must be an absolute path starting with /.

ExposeProtocolDecl

Defined in fuchsia.sys2/expose_decl.fidl

Declares a legacy service exposed to a component's containing realm, such as a legacy service exposed by the component or one of its children at runtime.

A legacy service is a service with a single instance, provided by a single FIDL protocol.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be self or child.
2	source_path	string[1024]	Path identifying the legacy service, by which it was presented to this component.
3	target	Ref	The destination to which the legacy service is exposed: either the component's realm or the framework.
4	target_path	string[1024]	The path by which the capability is being exposed. Must be an absolute path starting with /.

ExposeDirectoryDecl

Defined in fuchsia.sys2/expose_decl.fidl

Declares a directory exposed to a component's containing realm, such as a directory exposed by the component or one of its children at runtime.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be self or child.
2	source_path	string[1024]	Path identifying the directory, by which it was presented to this component.
3	target	Ref	The destination to which the directory is exposed: either the component's realm or the framework.
4	target_path	string[1024]	The path by which the capability is being exposed. Must be an absolute path starting with /.
5	rights	fuchsia.io2/Rights	The rights to expose this directory with, required iff source == self.
6	subdir	string[1024]	The subdirectory of this directory to expose instead of the root. Optional.

ExposeRunnerDecl

Defined in fuchsia.sys2/expose_decl.fidl

Declares a runner exposed to a component's containing realm, such as a runner exposed by the component or one of its children at runtime.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be self or child.
2	source_name	fuchsia.component/runner_name	The name of the runner, by which it was presented to this component.
3	target	Ref	The destination to which the runner is exposed: either the component's realm or the framework.
4	target_name	fuchsia.component/runner_name	The name by which the capability is being exposed.

ExposeResolverDecl

Defined in fuchsia.sys2/expose_decl.fidl

Declares a resolver exposed to a component's containing realm, such as a resolver exposed by the component or one of its children at runtime.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be self or child.
2	source_name	fuchsia.component/resolver_name	The name of the resolver, by which it was presented to this component.
3	target	Ref	The destination to which the resolver is exposed: either the component's realm or the framework.
4	target_name	fuchsia.component/resolver_name	The name by which the capability is being exposed.

OfferServiceDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares a service offered by a component to one of its children, which may have been offered by the component's containing realm, the component itself, or one of its other children.

To learn more about services, see: https://fuchsia.dev/fuchsia-src/glossary#service

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be realm, self, or child.
2	source_path	string[1024]	Path identifying the service being offered. Must be an absolute path starting with /.
3	target	Ref	Reference to the target. Must be child or collection.
4	target_path	string[1024]	The path under which the capability is being offered. Must be an absolute path starting with /.

OfferProtocolDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares a legacy service offered by a component to one of its children, which may have been offered by the component's containing realm, the component itself, or one of its other children.

A legacy service is a service with a single instance, provided by a single FIDL protocol.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be realm, self, or child.
2	source_path	string[1024]	Path identifying the legacy service being offered.
3	target	Ref	Reference to the target. Must be child or collection.
4	target_path	string[1024]	The path under which the capability is being offered. Must be an absolute path starting with /.
5	dependency_type	DependencyType	The dependency type this offer represents. A component which recieves a weak offer must support the offered capability being unavailable at any point.

OfferDirectoryDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares a directory offered by a component to one of its children, which may have been offered by the component's containing realm, the component itself, or one of its other children.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be realm, self, or child.
2	source_path	string[1024]	Path identifying the directory being offered.
3	target	Ref	Reference to the target of the capability. Must be child or collection.
4	target_path	string[1024]	The path under which the capability is being offered. Must be an absolute path starting with /.
5	rights	fuchsia.io2/Rights	The rights this directory should be offered with, required iff source == self.
6	subdir	string[1024]	The subdirectory of this directory to offer instead of the root. Optional.
7	dependency_type	DependencyType	The dependency type this offer represents. A component which recieves a weak offer must support the offered capability being unavailable at any point.

OfferStorageDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares a storage capability offered by a component to one of its children, such as meta storage offered by the component's containing realm or cache storage offered by the component itself.

Ordinal	Name	Type	Description
1	type	StorageType	The type of storage being offered.
2	source	Ref	The source of the storage capability. Must be realm or storage.
3	target	Ref	Reference to the target of the capability. Must be child or collection.

OfferRunnerDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares a runner offered by a component to one of its children, which may have been offered by the component's containing realm, the component itself, or one of its other children.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be realm, self, or child.
2	source_name	fuchsia.component/runner_name	Name of the runner being offered.
3	target	Ref	Reference to the target of the capability. Must be child or collection.
4	target_name	fuchsia.component/runner_name	Name under which the capability is being offered.

OfferResolverDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares a resolver capability offered by a component to one of its children, which may have been offered by the component's containing realm, the component itself, or one of its other children.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the capability relative to the component itself. Must be realm, self, or child.
2	source_name	fuchsia.component/resolver_name	Name of the resolver being offered.
3	target	Ref	Reference to the target of the capability. Must be child or collection.
4	target_name	fuchsia.component/resolver_name	Name under which the capability is being offered.

OfferEventDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares an event offered by a component.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the event. Must be realm.
2	source_name	fuchsia.component/event_name	Name of the event being offered.
3	target	Ref	Reference to the target of the event. Must be child or collection.
4	target_name	fuchsia.component/resolver_name	Name under which the event is being offered.
5	filter	fuchsia.data/Dictionary	Filter for the event. The structure of the filter depends on the event type. May be absent for some events.

ResolverDecl

Defined in fuchsia.sys2/resolver_decl.fidl

Declares a resolver which is responsible for resolving component URLs to actual components. See fuchsia.sys2.ComponentResolver for the protocol resolvers are expected to implement.

Ordinal	Name	Type	Description
1	name	fuchsia.component/resolver_name	The name of this resolver. Must be non-empty, unique among resolvers declared in the same ComponentDecl, and contain only the following characters: [a-z0-9-_.].
2	source_path	string[1024]	The path of the capability in the declaring component's namespace.

RunnerDecl

Defined in fuchsia.sys2/runner_decl.fidl

Declares a runner capability backed by a service.

Ordinal	Name	Type	Description
1	name	fuchsia.component/runner_name	The name of this runner.
2	source	Ref	The provider of the underlying service relative to the component itself. Must be realm, self, or child.
3	source_path	string[1024]	The path of the capability within the specified source.

StorageDecl

Defined in fuchsia.sys2/storage_decl.fidl

Declares a storage capability backed by a directory from which data, cache, or meta storage can be offered.

Ordinal	Name	Type	Description
1	name	string[100]	The name of this storage
2	source	Ref	The provider of the underlying directory capability relative to the component itself. Must be realm, self, or child.
3	source_path	string[1024]	The incoming path to the directory capability. If "source == SELF", this is a path in the component's outgoing directory. Otherwise, it is the path by which the capability was presented to the component.

UseServiceDecl

Defined in fuchsia.sys2/use_decl.fidl

Declares a service used by a component, which was offered to the component's environment.

To learn more about services, see: https://fuchsia.dev/fuchsia-src/glossary#service

Ordinal	Name	Type	Description
1	source	Ref	The provider of the service relative to the component itself. Must be realm or framework.
2	source_path	string[1024]	Path identifying the service, by which it was presented to this component. Must be an absolute path starting with /.
3	target_path	string[1024]	The path where the capability should be installed in the component's namespace. Must be an absolute path starting with /.

UseProtocolDecl

Defined in fuchsia.sys2/use_decl.fidl

Declares a legacy service used by a component, which was offered to the component's environment.

A legacy service is a service with a single instance, provided by a single FIDL protocol.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the legacy service relative to the component itself. Must be realm or framework.
2	source_path	string[1024]	Path identifying the legacy service, by which it was presented to this component.
3	target_path	string[1024]	The path where the capability should be installed in the component's namespace. Must be an absolute path starting with /.

UseDirectoryDecl

Defined in fuchsia.sys2/use_decl.fidl

Declares a directory used by a component, which was offered to the component's environment.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the directory relative to the component itself. Must be realm or framework.
2	source_path	string[1024]	Path identifying the directory, by which it was presented to this component.
3	target_path	string[1024]	The path where the capability should be installed in the component's namespace. Must be an absolute path starting with /.
4	rights	fuchsia.io2/Rights	The rights required by the component to use this directory.
5	subdir	string[1024]	The subdirectory of this directory to use instead of the root. Optional.

UseStorageDecl

Defined in fuchsia.sys2/use_decl.fidl

Declares storage used by a component, which was offered to the component's environment.

Ordinal	Name	Type	Description
1	type	StorageType	Type of storage used by the component.
2	target_path	string[1024]	The path where the capability should be installed in the component's namespace. Must not be set if type is META. Must be an absolute path starting with /.

UseRunnerDecl

Defined in fuchsia.sys2/use_decl.fidl

Declares a runner used by a component, which was offered to the component's environment.

Ordinal	Name	Type	Description
1	source_name	fuchsia.component/runner_name	The name of the runner, as it was presented to this component by the realm.

UseEventDecl

Defined in fuchsia.sys2/use_decl.fidl

Declares an event used by a component.

Ordinal	Name	Type	Description
1	source	Ref	The provider of the event. Must be |realm| or |framework|.
2	source_name	fuchsia.component/event_name	Name identifying the event which was presented to this component.
3	target_name	fuchsia.component/event_name	The name which the component will use to refer to this event.
4	filter	fuchsia.data/Dictionary	Filter for the event. The structure of the filter depends on the event type. May be absent for some events.

Component

Defined in fuchsia.sys2/component.fidl

A component is a unit of executable software.

This object provides the component's declaration, access to its package's content, and relevant metadata.

Ordinal	Name	Type	Description
1	resolved_url	string	The resolved URL of the component. This is the canonical URL obtained by the component resolver after following redirects and resolving relative paths.
2	decl	ComponentDecl	The component's declaration. This information is typically obtained from the component's manifest or generated by the component resolver.
3	package	Package	The package that contains the component. By convention, the component's package is mapped to "/pkg" in its namespace at runtime. This is null if the component is not represented as a package. In that case, it is the runner's responsibility to load the component's resource from the resolved_url. This mechanism is used for web applications. Most runners, including but not limited to the builtin ELF runner, require the package's directory connection to have OPEN_RIGHT_EXECUTABLE rights in order to run the resolved component.

Package

Defined in fuchsia.sys2/package.fidl

A package is a signed collection of immutable files.

This object provides access to a package's content and relevant metadata.

Ordinal	Name	Type	Description
1	package_url	string	The URL of the package itself.
2	package_dir	fuchsia.io/Directory	The package's content directory.

WorkRequest

Defined in fuchsia.sys2/work_scheduler.fidl

Parameters for a new piece of work to be scheduled.

Ordinal	Name	Type	Description
1	start	Start	Time when corresponding work item should be first scheduled.
2	period	zx/duration	Delay between repeated schedulings of corresponding work item. This is left unspecified for one-shot work that should not repeat. Repeating work items are rescheduled indefinitely until it is canceled.

UNIONS

ExposeDecl

Defined in fuchsia.sys2/expose_decl.fidl

Declares a capability exposed to either a component's containing realm or to the framework. For example, a legacy service exposed by the component at runtime.

Name	Type	Description
service	ExposeServiceDecl
protocol	ExposeProtocolDecl
directory	ExposeDirectoryDecl
runner	ExposeRunnerDecl
resolver	ExposeResolverDecl

Value

Defined in fuchsia.sys2/object.fidl

A value is a boolean, integer, float, string, vector, or object.

Name	Type	Description
bit	bool
inum	int64
fnum	float64
str	string
vec	Vector
obj	Object

OfferDecl

Defined in fuchsia.sys2/offer_decl.fidl

Declares a capability offered by a component to one of its children, which may have been offered by the component's containing realm, the component itself, or one of its other children.

Name	Type	Description
service	OfferServiceDecl
protocol	OfferProtocolDecl
directory	OfferDirectoryDecl
storage	OfferStorageDecl
runner	OfferRunnerDecl
resolver	OfferResolverDecl
event	OfferEventDecl

Ref

Defined in fuchsia.sys2/relative_refs.fidl

A reference to a capability source or destination relative to this component.

Name	Type	Description
realm	RealmRef
self	SelfRef
child	ChildRef
collection	CollectionRef
storage	StorageRef
framework	FrameworkRef

UseDecl

Defined in fuchsia.sys2/use_decl.fidl

Declares a capability used by a component, which was offered to the component's environment.

Name	Type	Description
service	UseServiceDecl
protocol	UseProtocolDecl
directory	UseDirectoryDecl
storage	UseStorageDecl
runner	UseRunnerDecl
event	UseEventDecl

Realm_BindChild_Result

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description
response	Realm_BindChild_Response
err	fuchsia.component/Error

Realm_CreateChild_Result

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description
response	Realm_CreateChild_Response
err	fuchsia.component/Error

Realm_DestroyChild_Result

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description
response	Realm_DestroyChild_Response
err	fuchsia.component/Error

Realm_ListChildren_Result

Defined in fuchsia.sys2/realm.fidl

Name	Type	Description
response	Realm_ListChildren_Response
err	fuchsia.component/Error

WorkScheduler_ScheduleWork_Result

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description
response	WorkScheduler_ScheduleWork_Response
err	fuchsia.component/Error

WorkScheduler_CancelWork_Result

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description
response	WorkScheduler_CancelWork_Response
err	fuchsia.component/Error

Worker_DoWork_Result

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description
response	Worker_DoWork_Response
err	fuchsia.component/Error

WorkSchedulerControl_GetBatchPeriod_Result

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description
response	WorkSchedulerControl_GetBatchPeriod_Response
err	fuchsia.component/Error

WorkSchedulerControl_SetBatchPeriod_Result

Defined in fuchsia.sys2/work_scheduler.fidl

Name	Type	Description
response	WorkSchedulerControl_SetBatchPeriod_Response
err	fuchsia.component/Error

Start

Defined in fuchsia.sys2/work_scheduler.fidl

Different ways to specify when to schedule a work item for the first time.

Name	Type	Description
delay	zx/duration	A non-negative delay to wait before scheduling work.
monotonic_time	zx/time	A fixed point in time to start scheduling work, interpreted like ZX_CLOCK_MONOTONIC: number of nanoseconds since the system was powered on.

CONSTANTS

Name	Value	Type	Description
MAX_WORK_ID_LENGTH	100	uint32

TYPE ALIASES

Name	Value	Description
WorkId	string[MAX_WORK_ID_LENGTH]