O1 heap, executor and main loop (#22)

- added `platform::O1HeapMemoryResource`
- added platform executor and main loop

Author: serges147

.github/workflows/build.yml

@@ -2,9 +2,13 @@ name: build
 
 on:
   push:
-    branches: [ "sshirokov/libcyphal" ]
+    branches:
+      - main
+      - 'issue/*'
   pull_request:
-    branches: [ "sshirokov/libcyphal" ]
+    branches:
+      - main
+      - 'issue/*'
 
 env:
   # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)

.vscode/settings.json

@@ -2,6 +2,7 @@
     "cSpell.words": [
         "baremetal",
         "Cyphal",
+        "libcyphal",
         "POSIX"
     ],
     "cmake.sourceDirectory": "/home/sergei/Develop/git/OpenCyphal-Garage/demos/libcyphal_demo"

libcyphal_demo/.clang-tidy

@@ -33,5 +33,4 @@ CheckOptions:
   - key:   readability-magic-numbers.IgnoredIntegerValues
     value: '1;2;3;4;5;8;10;16;20;32;60;64;100;128;256;500;512;1000'
 WarningsAsErrors: '*'
-HeaderFilterRegex: 'include/libcyphal/.*\.hpp'
 FormatStyle: file

libcyphal_demo/src/CMakeLists.txt

@@ -9,12 +9,13 @@ cmake_minimum_required(VERSION 3.20)
 # Define the demo application build target and link it with the library.
 add_executable(
         demo
+        ${CMAKE_SOURCE_DIR}/src/application.cpp
         ${CMAKE_SOURCE_DIR}/src/main.cpp
         ${CMAKE_SOURCE_DIR}/src/no_cpp_heap.cpp
 )
-target_link_libraries(demo PRIVATE udpard)
 target_link_libraries(demo PRIVATE canard)
 target_link_libraries(demo PRIVATE o1heap)
+target_link_libraries(demo PRIVATE udpard)
 target_include_directories(demo PRIVATE ${submodules}/cetl/include)
 target_include_directories(demo PRIVATE ${submodules}/libcyphal/include)
 add_dependencies(demo dsdl_uavcan)

libcyphal_demo/src/application.cpp

@@ -0,0 +1,38 @@
+// This software is distributed under the terms of the MIT License.
+// Copyright (C) OpenCyphal Development Team  <opencyphal.org>
+// Copyright Amazon.com Inc. or its affiliates.
+// SPDX-License-Identifier: MIT
+// Author: Sergei Shirokov <[email protected]>
+
+#include "application.hpp"
+
+#include <cetl/pf17/cetlpf.hpp>
+#include <o1heap.h>
+
+#include <array>
+#include <cstddef>
+#include <iostream>
+
+namespace
+{
+
+constexpr std::size_t HeapSize = 16ULL * 1024ULL;
+alignas(O1HEAP_ALIGNMENT) std::array<cetl::byte, HeapSize> s_heap_arena{};
+
+}  // namespace
+
+Application::Application()
+    : o1_heap_mr_{s_heap_arena}
+{
+}
+
+Application::~Application()
+{
+    const auto mr_diag = o1_heap_mr_.queryDiagnostics();
+    std::cout << "O(1) Heap diagnostics:" << "\n"
+              << "  tcapacity=" << mr_diag.capacity << "\n"
+              << "  tallocated=" << mr_diag.allocated << "\n"
+              << "  tpeak_allocated=" << mr_diag.peak_allocated << "\n"
+              << "  tpeak_request_size=" << mr_diag.peak_request_size << "\n"
+              << "  toom_count=" << mr_diag.oom_count << "\n";
+}

libcyphal_demo/src/application.hpp

@@ -0,0 +1,48 @@
+// This software is distributed under the terms of the MIT License.
+// Copyright (C) OpenCyphal Development Team  <opencyphal.org>
+// Copyright Amazon.com Inc. or its affiliates.
+// SPDX-License-Identifier: MIT
+// Author: Sergei Shirokov <[email protected]>
+
+#ifndef APPLICATION_HPP
+#define APPLICATION_HPP
+
+#include "platform/linux/epoll_single_threaded_executor.hpp"
+#include "platform/o1_heap_memory_resource.hpp"
+
+#include <cetl/pf17/cetlpf.hpp>
+
+/// The main application class.
+///
+/// Expected to be a singleton.
+///
+class Application final
+{
+public:
+    Application();
+    ~Application();
+
+    Application(const Application&)            = delete;
+    Application& operator=(const Application&) = delete;
+    Application(Application&&)                 = delete;
+    Application& operator=(Application&&)      = delete;
+
+    CETL_NODISCARD platform::Linux::EpollSingleThreadedExecutor& executor() noexcept
+    {
+        return executor_;
+    }
+
+    CETL_NODISCARD cetl::pmr::memory_resource& memory() noexcept
+    {
+        return o1_heap_mr_;
+    }
+
+private:
+    // MARK: Data members:
+
+    platform::Linux::EpollSingleThreadedExecutor executor_;
+    platform::O1HeapMemoryResource               o1_heap_mr_;
+
+};  // Application
+
+#endif  // APPLICATION_HPP

libcyphal_demo/src/main.cpp

@@ -4,13 +4,55 @@
 // SPDX-License-Identifier: MIT
 // Author: Sergei Shirokov <[email protected]>
 
+#include "application.hpp"
+
+#include <cetl/pf17/cetlpf.hpp>
 #include <libcyphal/application/node.hpp>
+#include <libcyphal/executor.hpp>
+#include <libcyphal/types.hpp>
 
+#include <algorithm>
+#include <chrono>
 #include <iostream>
 
+using namespace std::chrono_literals;
+
+using Callback = libcyphal::IExecutor::Callback;
+
 int main()
 {
-    const std::string str{"LibCyphal demo."};
-    std::cout << str << "\n";
+    Application application;
+    auto&       executor = application.executor();
+
+    std::cout << "LibCyphal demo." << "\n";
+
+    auto cb = executor.registerCallback([](auto&) {
+        //
+        std::cout << "Callback fired." << "\n";
+    });
+    cb.schedule(Callback::Schedule::Repeat{executor.now(), libcyphal::Duration{1s}});
+
+    // Main loop.
+    //
+    libcyphal::Duration        worst_lateness{0};
+    const libcyphal::TimePoint deadline = executor.now() + 4s;
+    std::cout << "-----------\nRunning..." << std::endl;  // NOLINT
+    //
+    while (executor.now() < deadline)
+    {
+        const auto spin_result = executor.spinOnce();
+        worst_lateness         = std::max(worst_lateness, spin_result.worst_lateness);
+
+        libcyphal::Duration timeout{1s};  // awake at least once per second
+        if (spin_result.next_exec_time.has_value())
+        {
+            timeout = std::min(timeout, spin_result.next_exec_time.value() - executor.now());
+        }
+        (void) executor.pollAwaitableResourcesFor(cetl::make_optional(timeout));
+    }
+    //
+    std::cout << "Done.\n-----------\nRun Stats:\n";
+    std::cout << "  worst_callback_lateness=" << worst_lateness.count() << "us\n";
+
     return 0;
 }