class ServiceMemberWatcher

Watch for service instances and connect to a member protocol of each instance.

ServiceMemberWatcher and SyncServiceMemberWatcher are templated on a ServiceMember, which

specifies both the service that it is a part of, and a member protocol of that service.

For a fidl protocol and service defined as:

library fidl.examples.echo;

protocol DriverEcho {...}

service DriverEchoService {

echo_device client_end:DriverEcho;

};

The ServiceMember would be: fidl_examples_echo::Service::EchoDevice

Note that the last part of the ServiceMember corresponds to the name of the

client_end in the service, not the protocol type.

Services can be waited on asynchronously with ServiceMemberWatcher and synchronously with

SyncServiceMemberWatcher. If you have a service with multiple protocols, and need to access

more than one protocol of a service for each instance, you can use component::ServiceWatcher

Define a callback function:

void OnInstanceFound(ClientEnd

<fidl

_examples_echo::DriverEcho> client_end) {...}

Optionally define an idle function, which will be called when all existing instances have been

enumerated:

void AllExistingEnumerated() {...}

Create the ServiceMemberWatcher:

ServiceMemberWatcher

<fidl

_examples_echo::Service::EchoDevice> watcher;

watcher->Begin(get_default_dispatcher(),

&OnInstanceFound

,

&AllExistingEnumerated

);

The ServiceMemberWatcher will stop upon destruction, or when |Cancel| is called.