From a967774f496c6b2b6a74cc0c1d9f2bb211c6a65d Mon Sep 17 00:00:00 2001
From: "jonathan.reichardt" <info@jonathan-reichardt.de>
Date: Wed, 10 Jun 2026 23:35:00 +0200
Subject: [PATCH] Add oals::rt platform shim

Extract RT primitives (SCHED_FIFO, SCHED_RR, CPU affinity,
clock_nanosleep) into oals::rt namespace in netutils/platform/rt.h+cpp
Linux behavior unchanged.
macOS no-op stubs (since there is no real RT support on mac in the same way as on Linux)
---
 .github/workflows/ci.yaml | 32 ++++++++++++++++++
 .gitignore                |  1 +
 netutils/CMakeLists.txt   |  2 ++
 netutils/rt.cpp           | 71 +++++++++++++++++++++++++++++++++++++++
 netutils/rt.h             | 20 +++++++++++
 5 files changed, 126 insertions(+)
 create mode 100644 .github/workflows/ci.yaml
 create mode 100644 .gitignore
 create mode 100644 netutils/rt.cpp
 create mode 100644 netutils/rt.h

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
index 0000000..00b1db1
--- /dev/null
+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,32 @@
+on:
+  push:
+    branches: ['**']
+  pull_request:
+    branches: ['**']
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install deps (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends cmake ninja-build
+
+      - name: Install deps (macOS)
+        if: runner.os == 'macOS'
+        run: brew install cmake ninja
+
+      - name: Configure
+        run: cmake -G Ninja -B build -DCMAKE_BUILD_TYPE=Debug
+
+      - name: Build
+        run: cmake --build build
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e864704
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+**/build/
\ No newline at end of file
diff --git a/netutils/CMakeLists.txt b/netutils/CMakeLists.txt
index 2837448..b353cbb 100644
--- a/netutils/CMakeLists.txt
+++ b/netutils/CMakeLists.txt
@@ -3,6 +3,8 @@ set(OAN_UTILS_SOURCES
         udp.h
         LowLatSocket.cpp
         LowLatSocket.h
+        rt.h
+        rt.cpp
 )
 
 if(EMBEDDED_BUILD)
diff --git a/netutils/rt.cpp b/netutils/rt.cpp
new file mode 100644
index 0000000..3ef8803
--- /dev/null
+++ b/netutils/rt.cpp
@@ -0,0 +1,71 @@
+// This file is part of the Open Audio Live System project, a live audio environment
+// Copyright (c) 2026 - Jonathan D Reichardt
+//
+// This project is distributed under the Creative Commons CC-BY-NC-SA licence. https://creativecommons.org/licenses/by-nc-sa/4.0
+
+
+#include "rt.h"
+
+
+#ifdef __linux__
+#include <iostream>
+#include <sched.h>
+#include <ctime>
+#else
+#include <ctime>
+#endif
+
+namespace oals::rt {
+#ifdef __linux__
+    void set_thread_realtime(uint8_t prio) {
+        sched_param sparams{};
+        sparams.sched_priority = prio;
+
+        if (sched_setscheduler(0, SCHED_FIFO, &sparams) != 0) {
+            std::cerr << "[oals::rt] set_thread_realtime failed" << std::endl;
+        }
+    }
+    void set_running_cpu(int cpu_id) {
+        cpu_set_t cs{};
+        CPU_ZERO(&cs);
+        CPU_SET(cpu_id, &cs);
+
+        if (sched_setaffinity(0, sizeof(cpu_set_t), &cs) != 0) {
+            std::cerr << "[oals::rt] set_running_cpu failed" << std::endl;
+        }
+    }
+
+    void set_process_scheduler_rr(int prio) {
+        sched_param params{};
+        params.sched_priority = prio;
+        if (sched_setscheduler(0, SCHED_RR, &params) != 0) {
+            std::cerr << "[oals::rt] set_process_scheduler_rr failed" << std::endl;
+        }
+    }
+
+    void precise_sleep(long ns) {
+        timespec ts{};
+        ts.tv_sec = ns / 1'000'000'000;
+        ts.tv_nsec = ns % 1'000'000'000;
+        clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, nullptr);
+    }
+
+
+#else
+    void set_thread_realtime(uint8_t) {
+    }
+
+    void set_running_cpu(int) {
+    }
+
+    void set_process_scheduler_rr(int) {
+    }
+
+    void precise_sleep(long ns) {
+        timespec ts{};
+        ts.tv_sec = ns / 1'000'000'000;
+        ts.tv_nsec = ns % 1'000'000'000;
+        nanosleep(&ts, nullptr);
+    }
+#endif
+}
diff --git a/netutils/rt.h b/netutils/rt.h
new file mode 100644
index 0000000..2acbdd3
--- /dev/null
+++ b/netutils/rt.h
@@ -0,0 +1,20 @@
+// This file is part of the Open Audio Live System project, a live audio environment
+// Copyright (c) 2026 - Jonathan D Reichardt
+//
+// This project is distributed under the Creative Commons CC-BY-NC-SA licence. https://creativecommons.org/licenses/by-nc-sa/4.0
+
+
+#ifndef OPENAUDIONETWORK_RT_H
+#define OPENAUDIONETWORK_RT_H
+#include <cstdint>
+
+
+namespace oals::rt {
+    void set_thread_realtime(uint8_t);
+    void set_running_cpu(int);
+    void set_process_scheduler_rr(int);
+    void precise_sleep(long);
+}
+
+
+#endif //OPENAUDIONETWORK_RT_H