`zerodds-dcps-async`

Runtime-agnostic async wrappers around the zerodds-dcps sync API. Newtypes share the internal Arc<...> with the sync counterparts — no state duplicate, no performance overhead. Safety classification: STANDARD.

Spec mapping

Spec	Section
ZeroDDS-async 1.0	§1–§9 (complete)
OMG DDS 1.4	§2.2.2.4–5 (DataWriter/DataReader API)

What's inside

Async newtypes — AsyncDomainParticipantFactory, AsyncDomainParticipant, AsyncPublisher, AsyncDataWriter<T>, AsyncSubscriber, AsyncDataReader<T>. Each newtype holds an Arc<...> to the sync counterpart.
write().await — yield-based retry loop on OutOfResources backpressure (spec §5.1). The Condvar::wait_timeout sync block is replaced by a yield_for Future; caller tasks stay cancelable.
take(timeout).await — polling Future with deadline; empty Vec<T> on timeout (analogous to sync semantics).
SampleStream (spec §2.2.1) — Stream<Item = T>. Live mode uses register_user_reader_waker on the runtime; wake happens on sample_tx.send (no polling). Offline mode: detached-thread sleep as polling fallback (spec §3.3).
DataAvailableStream (spec §6.1) — Stream<Item = ()>. Signals "new data available" per sample inflow; consumes no samples (the caller calls take() separately).
PublicationMatchedStream (spec §6.2) — Stream<Item = SubscriptionMatchedStatus>. Emits the full reader-side match status (DDS 1.4 §2.2.4.1 SUBSCRIPTION_MATCHED) on every change.
wait_for_matched_* Futures — async polling loops with deadline.

Layer position

Layer 4 — Core Services. Built on zerodds-dcps (layer 4) and zerodds-qos (layer 1). Runtime-agnostic — uses futures-core::Stream, optionally tokio::time::sleep with feature tokio-glue. The default path is detached-thread sleep.

Quickstart

use zerodds_dcps_async::{
    AsyncDomainParticipantFactory, DataReaderQos, DataWriterQos,
    PublisherQos, SubscriberQos, TopicQos,
};
use zerodds_dcps::RawBytes;

#[tokio::main]
async fn main() {
    let factory = AsyncDomainParticipantFactory::instance();
    let participant = factory.create_participant_offline(0);
    let topic = participant
        .create_topic::<RawBytes>("Chatter", TopicQos::default())
        .expect("topic");

    let pub_ = participant.create_publisher(PublisherQos::default());
    let writer = pub_
        .create_datawriter::<RawBytes>(&topic, DataWriterQos::default())
        .expect("writer");
    writer.write(&RawBytes::new(vec![1, 2, 3])).await.unwrap();
}

Feature flags

Feature	Default	Purpose
`std`	✅	Standard library + threads + detached-thread sleep.
`tokio-glue`	❌	`tokio::time::sleep` as backend for `yield_for` (instead of detached thread). Reduces spawn overhead with a tokio-based caller.

Stability

All pub items are stable from 1.0.0; breaking changes require a major bump.

Tests

cargo test -p zerodds-dcps-async

License

Apache-2.0. See LICENSE.

zerodds-dcps-async 1.0.0-rc.5