cpptick - initial

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.8 FATAL_ERROR)
 
-set(SKULLC_VERSION 0.1.0)
+set(SKULLC_VERSION 0.2.0)
 
 project(skullc
         VERSION ${SKULLC_VERSION}
@@ -19,6 +19,7 @@ include(skullc-install)
 
 add_subdirectory(Peripherals)
 add_subdirectory(Utility)
+add_subdirectory(CppTick)
 add_subdirectory(Messaging)
 
 if(SKULLC_WITH_TESTS)

CppTick/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.8 FATAL_ERROR)
+
+add_library(cpptick INTERFACE)
+add_library(skullc::cpptick ALIAS cpptick)
+
+target_include_directories(cpptick
+    INTERFACE
+        $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/Inc>
+        $<INSTALL_INTERFACE:include>
+)
+
+set_target_properties(cpptick
+    PROPERTIES
+        CXX_STANDARD 20
+        CXX_STANDARD_REQUIRED TRUE
+)
+
+target_link_libraries(cpptick
+    INTERFACE
+        skullc::utility
+)
+
+skullc_install_packages(skullc cpptick ${SKULLC_VERSION})

CppTick/Inc/cpptick/cpptick.hpp

@@ -0,0 +1,235 @@
+//
+// Created by erki on 12/09/23.
+//
+
+#pragma once
+
+#include <type_traits>
+#include <memory>
+#include <array>
+#include <cstring>
+
+#include <utility_function.hpp>
+#include <utility_ringbuffer.hpp>
+
+namespace cpptick
+{
+
+template<typename T>
+concept TrivialClass = std::is_trivial_v<T> && std::is_trivially_destructible_v<T>;
+
+template<typename T>
+concept CopyableClass = !TrivialClass<T> && std::copy_constructible<T>;
+
+template<typename T>
+concept SlotArgument = TrivialClass<T> || CopyableClass<T>;
+
+struct ArgStorage
+{
+  std::array<char, sizeof(int) * 12> buffer;
+  std::array<char*, 12> pointer_buffer;
+  std::array<char*, 12>::iterator pointer_buffer_head;
+  std::size_t space_remaining;
+
+  ArgStorage() = default;
+  ArgStorage(const ArgStorage&) = default;
+  ArgStorage(ArgStorage&&) = default;
+
+  void reset()
+  {
+    space_remaining = buffer.size();
+    pointer_buffer_head = pointer_buffer.begin();
+    *pointer_buffer_head = buffer.data();
+  }
+
+  template<TrivialClass T>
+  void pushArg(T&& arg)
+  {
+    if (pointer_buffer_head == pointer_buffer.end() || space_remaining == 0)
+      std::exit(1);
+
+    void* memory_location = *pointer_buffer_head;
+
+    if (std::align(alignof(T), sizeof(T), memory_location, space_remaining) == nullptr)
+      std::exit(2);
+
+    std::memcpy(memory_location, &arg, sizeof(T));
+    pointer_buffer_head++;
+    if (pointer_buffer_head != pointer_buffer.end())
+    {
+      *pointer_buffer_head = (char*)memory_location + sizeof(T);
+      space_remaining -= sizeof(T);
+    }
+  }
+
+  template<CopyableClass T>
+  void pushArg(T&& arg)
+  {
+    if (pointer_buffer_head == pointer_buffer.end() || space_remaining == 0)
+      std::exit(1);
+
+    void* memory_location = *pointer_buffer_head;
+
+    if (std::align(alignof(T), sizeof(T), memory_location, space_remaining) == nullptr)
+      std::exit(2);
+
+    new (memory_location) T{arg};
+    pointer_buffer_head++;
+    if (pointer_buffer_head != pointer_buffer.end())
+    {
+      *pointer_buffer_head = (char*)memory_location + sizeof(T);
+      space_remaining -= sizeof(T);
+    }
+  }
+
+  template<TrivialClass T>
+  void cleanUp(const std::size_t)
+  { }
+
+  template<CopyableClass T>
+  void cleanUp(const std::size_t index)
+  {
+    T* item = reinterpret_cast<T*>(pointer_buffer[index]);
+    item->~T();
+  }
+
+  template<typename... Args, size_t... Is>
+  void cleanUp(std::index_sequence<Is...>)
+  {
+    (cleanUp<Args>(Is), ...);
+  }
+
+  template<typename... Args>
+  void cleanUp()
+  {
+    cleanUp<Args...>(std::make_index_sequence<sizeof...(Args)>{});
+  }
+
+  template<SlotArgument T>
+  T& at(const std::size_t idx)
+  {
+    return *((T*)pointer_buffer[idx]);
+  }
+
+  template<SlotArgument T>
+  const T& at(const std::size_t idx) const
+  {
+    return *((T*)pointer_buffer[idx]);
+  }
+};
+
+struct Scheduler
+{
+  using StoredCall = std::pair<Utility::IFunction<void (ArgStorage&)>*, ArgStorage>;
+  Utility::Ringbuffer<StoredCall, 12> stored_calls;
+
+  void tick()
+  {
+    if (!stored_calls.empty())
+    {
+      auto* f = stored_calls.begin()->first;
+      auto& args = stored_calls.begin()->second;
+      (*f)(args);
+      stored_calls.pop_front();
+    }
+  }
+
+  ArgStorage& storeCall(Utility::IFunction<void (ArgStorage&)>* call)
+  {
+    // @todo: handle overflow...
+    
+    // still constructs double.
+    stored_calls.emplace_back(call, ArgStorage{});
+    auto& storage = stored_calls.back().second;
+    storage.reset();
+    return storage;
+  }
+};
+
+template<typename>
+struct Slot;
+
+template<typename R, SlotArgument... Args>
+struct Slot<R(Args...)>
+{
+  std::array<Utility::IFunction<R (Args...)>*, 12> signals;
+  Scheduler* scheduler;
+
+  Utility::FunctionOwned<Slot<R(Args...)>, void (ArgStorage&)> invoke_ptr;
+
+  Slot() = delete;
+  explicit Slot(Scheduler* sched)
+      : scheduler(sched)
+      , invoke_ptr(*this, &Slot<R(Args...)>::callUp)
+  {
+    signals.fill(nullptr);
+  }
+
+  Slot(const Slot&) = delete;
+  Slot(Slot&&) = delete;
+  Slot& operator=(const Slot&) = delete;
+  Slot& operator=(Slot&&) = delete;
+
+  void connect(Utility::IFunction<R (Args...)>* signal)
+  {
+    for (auto*& callable : signals)
+    {
+      if (callable == nullptr)
+      {
+        callable = signal;
+        break;
+      }
+    }
+  }
+
+  Utility::IFunction<R (Args...)>* connect(R (*func)(Args...))
+  {
+    auto* f = new Utility::Function<R (Args...)>(func);
+
+    connect(f);
+
+    return f;
+  }
+
+  template<typename Source>
+  Utility::IFunction<R (Args...)>* connect(Source& src, R (Source::* func)(Args...))
+  {
+    auto* f = new Utility::FunctionOwned<Source, R (Args...)>(src, func);
+
+    connect(f);
+
+    return f;
+  }
+
+  template<size_t... Is>
+  void callUpFunction(Utility::IFunction<R (Args...)>* func, ArgStorage& args, std::index_sequence<Is...>)
+  {
+    (*func)(std::forward<Args>(args.at<Args>(Is))...);
+  }
+
+  void callUpFunction(Utility::IFunction<R (Args...)>* func, ArgStorage& args)
+  {
+    callUpFunction(func, args, std::make_index_sequence<sizeof...(Args)>{});
+  }
+
+  void callUp(ArgStorage& args)
+  {
+    for (auto* f : signals)
+    {
+      if (f)
+        callUpFunction(f, args);
+      else
+        break;
+    }
+
+    args.cleanUp<Args...>();
+  }
+
+  void invoke(Args... args)
+  {
+    ArgStorage& storage = scheduler->storeCall(&invoke_ptr);
+    (storage.pushArg(std::forward<Args>(args)), ...);
+  }
+};
+
+}

CppTick/cpptick-config.cmake.in

@@ -0,0 +1,2 @@
+include(${CMAKE_CURRENT_LIST_DIR}/skullc-cpptick-config-version.cmake)
+include(${CMAKE_CURRENT_LIST_DIR}/skullc-cpptick-targets.cmake)

Tests/CMakeLists.txt

@@ -31,6 +31,7 @@ add_executable(tests
     enum_helpers.cpp
     bytes.cpp
     filters.cpp
+    cpptick.cpp
 )
 
 target_link_libraries(tests
@@ -39,11 +40,12 @@ target_link_libraries(tests
         skullc::messaging
         skullc::peripherals
         Catch2::Catch2
+        skullc::cpptick
 )
 
 set_target_properties(tests
     PROPERTIES
-        CXX_STANDARD 17
+        CXX_STANDARD 20
 )
 
 list(APPEND CMAKE_MODULE_PATH ${catch2_SOURCE_DIR}/contrib)

Tests/cpptick.cpp

@@ -0,0 +1,98 @@
+//
+// Created by erki on 12/09/23.
+//
+
+#include <catch2/catch.hpp>
+
+#include <cpptick/cpptick.hpp>
+
+namespace
+{
+
+int callback_count = 0;
+
+void callbackByOne()
+{
+  callback_count += 1;
+}
+
+void callbackByN(int to_add)
+{
+  callback_count += to_add;
+}
+
+}
+
+TEST_CASE("Slot calls function properly with void args.", "[cpptick]")
+{
+  cpptick::Scheduler scheduler;
+
+  cpptick::Slot<void ()> slot(&scheduler);
+  auto* f = slot.connect(callbackByOne);
+
+  callback_count = 0;
+  REQUIRE(callback_count == 0);
+
+  SECTION("invoke() calls the slot appropriately.")
+  {
+    slot.invoke();
+    CHECK(callback_count == 0);
+
+    scheduler.tick();
+    CHECK(callback_count == 1);
+
+    SECTION("Second tick doesn't invoke the slot again.")
+    {
+      scheduler.tick();
+      CHECK(callback_count == 1);
+    }
+
+    SECTION("Second invoke() will call the slot again.")
+    {
+      slot.invoke();
+      scheduler.tick();
+      CHECK(callback_count == 2);
+    }
+  }
+
+  SECTION("Multiple calls queue properly.")
+  {
+    const int count = 3;
+    for (int i = 0; i < count; i++)
+    {
+      slot.invoke();
+    }
+
+    for (int i = 0; i < count; i++)
+    {
+      CHECK(callback_count == i);
+      scheduler.tick();
+      CHECK(callback_count == i + 1);
+    }
+  }
+
+  delete f;
+}
+
+TEST_CASE("Slot calls function properly with args.", "[cpptick]")
+{
+  cpptick::Scheduler scheduler;
+
+  cpptick::Slot<void (int)> slot(&scheduler);
+  auto* f = slot.connect(callbackByN);
+
+  callback_count = 0;
+  REQUIRE(callback_count == 0);
+
+  SECTION("invoke() passes argument appropriately.")
+  {
+    const int to_add = 5;
+    slot.invoke(to_add);
+    CHECK(callback_count == 0);
+
+    scheduler.tick();
+    CHECK(callback_count == to_add);
+  }
+
+  delete f;
+}