feat(rtps_embedded): embeddedRTPS integration + idiomatic espp refactor (facade, SocketReactor, protocol scheduler, Micro-CDR removal)

.github/workflows/rtps_interop.yml

@@ -0,0 +1,30 @@
+name: RTPS interop (FastDDS / ROS 2)
+
+# Minimal token scope: the harness only checks out and builds, never writes.
+permissions:
+  contents: read
+
+on:
+  pull_request:
+    paths:
+      - "components/rtps_embedded/**"
+      - "components/rtps/**"
+      - "components/socket/**"
+      - "components/cdr/**"
+      - "lib/espp.cmake"
+      - "pc/tests/rtps_embedded_*"
+      - ".github/workflows/rtps_interop.yml"
+  workflow_dispatch:
+
+jobs:
+  interop:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          submodules: "recursive"
+      - name: Run interop matrix
+        run: |
+          cd components/rtps_embedded/interop
+          ./run.sh

.gitignore

@@ -34,6 +34,7 @@
 # build folder for ESP-IDF
 build/
 
+
 # we only version sdkconfig.defaults
 sdkconfig
 sdkconfig.old
@@ -51,3 +52,6 @@ managed_components/
 
 # local-only agent customizations
 .github/agents/
+
+# docker interop harness build tree (bind-mounted, built in-container)
+pc/build-linux/

components/rtps_embedded/CMakeLists.txt

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+idf_component_register(
+  SRCS
+    "src/rtps_participant.cpp"
+    "src/communication/EsppTransport.cpp"
+    "src/discovery/ParticipantProxyData.cpp"
+    "src/discovery/SEDPAgent.cpp"
+    "src/discovery/SPDPAgent.cpp"
+    "src/discovery/TopicData.cpp"
+    "src/entities/Domain.cpp"
+    "src/entities/Participant.cpp"
+    "src/entities/Reader.cpp"
+    "src/entities/StatelessReader.cpp"
+    "src/entities/Writer.cpp"
+    "src/messages/MessageReceiver.cpp"
+    "src/messages/MessageTypes.cpp"
+    "src/utils/Diagnostics.cpp"
+  INCLUDE_DIRS
+    "include"
+  REQUIRES
+    base_component cdr task thread_pool socket
+)
+

components/rtps_embedded/README.md

@@ -0,0 +1,159 @@
+# rtps_embedded
+
+ESPP component that integrates the [embeddedRTPS](https://github.com/embedded-software-laboratory/embeddedRTPS)
+RTPS/DDS stack into the ESPP ecosystem.  
+Any platform that can build ESPP — including ESP32, Linux, and desktop PCs —
+can use this component to discover and exchange typed messages with ROS 2 nodes
+or any other DDS participant on the same network using the standard RTPS wire
+protocol.
+
+The original embeddedRTPS library has hard dependencies on FreeRTOS and lwIP.
+`rtps_embedded` removes those dependencies by replacing all socket, task, and
+synchronisation calls with ESPP's platform-agnostic `UdpSocket`, `Task`, and
+`ThreadPool` primitives.  When built for ESP32, ESPP uses FreeRTOS and lwIP
+under the hood; on other platforms it uses the host OS equivalents — the RTPS
+code itself is unchanged in either case.
+
+---
+
+## Architecture
+
+```
+user code
+    │
+    ▼
+rtps::Domain          — routes packets to participants; owns discovery threads
+    │
+    ├── rtps::Participant   — groups writers and readers
+    │       ├── rtps::Writer  — publishes CacheChange samples
+    │       └── rtps::Reader  — delivers samples to a user callback
+    │
+    ├── rtps::ThreadPool    — espp::ThreadPool workers that drain the four
+    │                         incoming/outgoing meta/user traffic queues
+    │
+    └── rtps::EsppTransport — one espp::UdpSocket per open UDP port,
+                              each with its own receive task
+```
+
+`EsppTransport` is the sole platform-specific adapter.  It wraps ESPP's
+`UdpSocket` and `Task`, which in turn map to:
+
+| Build target | Socket backend | Task backend |
+|---|---|---|
+| ESP32 | lwIP (via ESP-IDF) | FreeRTOS |
+| Linux / PC | POSIX sockets | `std::thread` |
+
+---
+
+## Quick-start
+
+```cpp
+#include "rtps/entities/Domain.h"
+
+// 1. Construct the domain with the local interface IP.
+rtps::Domain domain(local_ip);
+
+// 2. Create a participant *before* completeInit().
+rtps::Participant *part = domain.createParticipant();
+
+// 3. Add user-defined writer and reader endpoints.
+rtps::Writer *writer = domain.createWriter(*part, "my/topic",
+                                           "std_msgs::msg::String", false);
+rtps::Reader *reader = domain.createReader(*part, "my/topic",
+                                           "std_msgs::msg::String", false);
+
+// 4. Register a receive callback on the reader.
+reader->registerCallback(
+    [](void *, const rtps::ReaderCacheChange &change) {
+        // process change.getData() / change.copyInto(...)
+    }, nullptr);
+
+// 5. Start discovery (SPDP/SEDP) and worker threads.
+domain.completeInit();
+
+// 6. Publish a sample.
+const char *payload = "hello";
+writer->newChange(rtps::ChangeKind_t::ALIVE,
+                  reinterpret_cast<const uint8_t *>(payload),
+                  static_cast<rtps::DataSize_t>(strlen(payload) + 1));
+```
+
+> **Note**: `createParticipant()` **must** be called before `completeInit()`.
+> No new participants can be added after init is complete.
+
+---
+
+## Configuration
+
+Two built-in config headers are provided. Select one by defining
+`RTPS_CONFIG_HEADER`, or let `include/rtps/config.h` pick automatically based
+on the build target.
+
+| Header | Target |
+|---|---|
+| [`include/rtps/config_esp32.h`](include/rtps/config_esp32.h) | ESP32 (ESP-IDF) |
+| [`include/rtps/config_desktop.h`](include/rtps/config_desktop.h) | Linux / PC |
+
+All tunable constants follow the same layout in both files:
+
+| Constant | Default | Description |
+|---|---|---|
+| `DOMAIN_ID` | 0 | RTPS domain number (0–230 with UDP) |
+| `MAX_NUM_PARTICIPANTS` | 1 | Participant pool size |
+| `NUM_STATEFUL_WRITERS` | 5 | User writer endpoint pool |
+| `NUM_STATEFUL_READERS` | 5 | User reader endpoint pool |
+| `NUM_STATELESS_WRITERS` | 5 | Discovery writer endpoint pool |
+| `NUM_STATELESS_READERS` | 5 | Discovery reader endpoint pool |
+| `NUM_WRITERS_PER_PARTICIPANT` | 10 | Max writers per participant |
+| `NUM_READERS_PER_PARTICIPANT` | 10 | Max readers per participant |
+| `HISTORY_SIZE_STATEFUL` | 10 | Per-endpoint history depth |
+| `THREAD_POOL_NUM_WRITERS` | 2 | Writer worker threads |
+| `THREAD_POOL_NUM_READERS` | 2 | Reader worker threads |
+| `THREAD_POOL_WRITER_STACKSIZE` | 4096 B | Writer task stack |
+| `THREAD_POOL_READER_STACKSIZE` | 6144 B | Reader / UDP-receive task stack |
+| `MAX_NUM_UDP_CONNECTIONS` | 10 | UDP socket pool size |
+| `SPDP_RESEND_PERIOD_MS` | 2000 | Discovery announce period |
+| `SF_WRITER_HB_PERIOD_MS` | 4000 | Reliable-writer heartbeat period |
+
+The `OVERALL_HEAP_SIZE` constant at the bottom of that file estimates the
+total stack RAM consumed by all internal tasks.
+
+---
+
+## ESPP component dependencies
+
+| Component | Purpose |
+|---|---|
+| `base_component` | ESPP base class with integrated `espp::Logger` |
+| `socket` | ESPP `UdpSocket` used by `EsppTransport` |
+| `task` | ESPP `Task` for per-port UDP receive loops |
+| `thread_pool` | ESPP `ThreadPool` for writer/reader workers |
+| `cdr` | CDR serialization helpers |
+
+These components abstract away all OS and network-stack details, so
+`rtps_embedded` itself has no direct dependency on FreeRTOS, lwIP, or any
+other platform library. Discovery (SPDP/SEDP) parameter-list serialization is
+built on the espp `cdr` component's stream primitives (see
+`include/rtps/utils/CdrBuffer.hpp`); the engine carries no vendored
+third-party code.
+
+---
+
+## Example
+
+See [`example/`](example/) for a two-node **initiator / responder** demo.
+
+The same logic runs on any ESPP-supported platform. For ESP32, flash one board
+as *Initiator* and a second as *Responder* via menuconfig
+(`idf.py menuconfig → RTPS Example Configuration`). The initiator periodically
+publishes numbered request messages; the responder echoes each message back on
+the response topic.
+
+Key menuconfig options (ESP32 example):
+
+| Option | Description |
+|---|---|
+| `RTPS_EXAMPLE_ROLE` | `Initiator` or `Responder` |
+| `RTPS_EXAMPLE_TOPIC_PREFIX` | Shared topic prefix (e.g. `espp/rtps_example`) |
+| `RTPS_EXAMPLE_PUBLISH_PERIOD_MS` | Initiator publish interval |
+| `ESP_WIFI_SSID` / `ESP_WIFI_PASSWORD` | Wi-Fi credentials |