Struct WaitSet

pub struct WaitSet { /* private fields */ }

A struct for waiting on subscriptions and other waitable entities to become ready.

Implementations

impl WaitSet

pub fn new( number_of_subscriptions: usize, number_of_guard_conditions: usize, number_of_timers: usize, number_of_clients: usize, number_of_services: usize, number_of_events: usize, context: &Context, ) -> Result<Self, RclrsError>

Creates a new wait set.

The given number of subscriptions is a capacity, corresponding to how often WaitSet::add_subscription may be called.

pub fn new_for_node(node: &Node) -> Result<Self, RclrsError>

Creates a new wait set and adds all waitable entities in the node to it.

The wait set is sized to fit the node exactly, so there is no capacity for adding other entities.

pub fn clear(&mut self)

Removes all entities from the wait set.

This effectively resets the wait set to the state it was in after being created by WaitSet::new.

pub fn add_subscription( &mut self, subscription: Arc<dyn SubscriptionBase>, ) -> Result<(), RclrsError>

Adds a subscription to the wait set.

Errors

• If the subscription was already added to this wait set or another one, AlreadyAddedToWaitSet will be returned
• If the number of subscriptions in the wait set is larger than the capacity set in WaitSet::new, WaitSetFull will be returned

pub fn add_guard_condition( &mut self, guard_condition: Arc<GuardCondition>, ) -> Result<(), RclrsError>

Adds a guard condition to the wait set.

Errors

• If the guard condition was already added to this wait set or another one, AlreadyAddedToWaitSet will be returned
• If the number of guard conditions in the wait set is larger than the capacity set in WaitSet::new, WaitSetFull will be returned

pub fn add_client( &mut self, client: Arc<dyn ClientBase>, ) -> Result<(), RclrsError>

Adds a client to the wait set.

Errors

• If the client was already added to this wait set or another one, AlreadyAddedToWaitSet will be returned
• If the number of clients in the wait set is larger than the capacity set in WaitSet::new, WaitSetFull will be returned

pub fn add_service( &mut self, service: Arc<dyn ServiceBase>, ) -> Result<(), RclrsError>

Adds a service to the wait set.

Errors

• If the service was already added to this wait set or another one, AlreadyAddedToWaitSet will be returned
• If the number of services in the wait set is larger than the capacity set in WaitSet::new, WaitSetFull will be returned

pub fn wait( self, timeout: Option<Duration>, ) -> Result<ReadyEntities, RclrsError>

Blocks until the wait set is ready, or until the timeout has been exceeded.

If the timeout is None then this function will block indefinitely until something in the wait set is valid or it is interrupted.

If the timeout is Duration::ZERO then this function will be non-blocking; checking what’s ready now, but not waiting if nothing is ready yet.

If the timeout is greater than Duration::ZERO then this function will return after that period of time has elapsed or the wait set becomes ready, which ever comes first.

This function does not change the entities registered in the wait set.

Errors

• Passing a wait set with no wait-able items in it will return an error.
• The timeout must not be so large so as to overflow an i64 with its nanosecond representation, or an error will occur.

This list is not comprehensive, since further errors may occur in the rmw or rcl layers.

Trait Implementations

impl Sync for WaitSet