better timers

Firmware/components/backend-esp/CMakeLists.txt

@@ -4,6 +4,7 @@ idf_component_register(
         "src/buttons.cpp"
         "src/buzzer.cpp"
         "src/esp_backend.cpp"
+        "src/event_bus.cpp"
         "src/display.cpp"
         "src/fs_helper.cpp"
         "src/i2c_global.cpp"

Firmware/components/backend-esp/include/cardboy/backend/esp/buttons.hpp

@@ -5,9 +5,11 @@
 #ifndef BUTTONS_HPP
 #define BUTTONS_HPP
 
+#include "cardboy/sdk/event_bus.hpp"
+
+#include <cstdint>
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
-#include <cstdint>
 
 typedef enum {
     BTN_START  = 1 << 1,
@@ -25,16 +27,18 @@ public:
     static Buttons& get();
     void            pooler(); // FIXME:
     uint8_t         get_pressed();
-    void install_isr();
-    void register_listener(TaskHandle_t task);
+    void            install_isr();
+    void            register_listener(TaskHandle_t task);
+    void            setEventBus(cardboy::sdk::IEventBus* bus);
 
-    TaskHandle_t     _pooler_task;
+    TaskHandle_t _pooler_task;
 
 private:
     Buttons();
 
-    volatile uint8_t _current;
-    volatile TaskHandle_t _listener = nullptr;
+    volatile uint8_t         _current;
+    volatile TaskHandle_t    _listener = nullptr;
+    cardboy::sdk::IEventBus* _eventBus = nullptr;
 };
 
 

Firmware/components/backend-esp/include/cardboy/backend/esp/event_bus.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <cardboy/sdk/event_bus.hpp>
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+#include "freertos/timers.h"
+
+namespace cardboy::backend::esp {
+
+class EventBus final : public cardboy::sdk::IEventBus {
+public:
+    EventBus();
+    ~EventBus() override;
+
+    void          signal(std::uint32_t bits) override;
+    void          signalFromISR(std::uint32_t bits) override;
+    std::uint32_t wait(std::uint32_t mask, std::uint32_t timeout_ms) override;
+    void          scheduleTimerSignal(std::uint32_t delay_ms) override;
+    void          cancelTimerSignal() override;
+
+private:
+    EventGroupHandle_t group;
+    TimerHandle_t      timer;
+};
+
+} // namespace cardboy::backend::esp

Firmware/components/backend-esp/include/cardboy/backend/esp_backend.hpp

@@ -2,6 +2,7 @@
 
 #include <cardboy/sdk/display_spec.hpp>
 #include "cardboy/backend/esp/display.hpp"
+#include "cardboy/backend/esp/event_bus.hpp"
 #include "cardboy/sdk/platform.hpp"
 #include "cardboy/sdk/services.hpp"
 
@@ -68,6 +69,7 @@ private:
     std::unique_ptr<HighResClockService> highResClockService;
     std::unique_ptr<PowerService>        powerService;
     std::unique_ptr<FilesystemService>   filesystemService;
+    std::unique_ptr<EventBus>            eventBus;
 
     cardboy::sdk::Services services{};
 };

Firmware/components/backend-esp/src/buttons.cpp

@@ -6,14 +6,15 @@
 
 #include <driver/gpio.h>
 #include <esp_err.h>
-#include "cardboy/backend/esp/power_helper.hpp"
 #include <rom/ets_sys.h>
+#include "cardboy/backend/esp/power_helper.hpp"
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 
 #include "cardboy/backend/esp/config.hpp"
 #include "cardboy/backend/esp/i2c_global.hpp"
+#include "cardboy/sdk/event_bus.hpp"
 
 static i2c_master_dev_handle_t    dev_handle;
 static inline i2c_device_config_t dev_cfg = {
@@ -92,9 +93,13 @@ void Buttons::pooler() {
                 i2c_master_transmit_receive(dev_handle, &reg, sizeof(reg), reinterpret_cast<uint8_t*>(&buffer), 1, -1));
         if (_listener)
             xTaskNotifyGive(_listener);
+        if (_eventBus)
+            _eventBus->signal(cardboy::sdk::to_event_bits(cardboy::sdk::EventBusSignal::Input));
     }
 }
 uint8_t Buttons::get_pressed() { return _current; }
 void    Buttons::install_isr() { gpio_isr_handler_add(EXP_INT, wakeup, nullptr); }
 
 void Buttons::register_listener(TaskHandle_t task) { _listener = task; }
+
+void Buttons::setEventBus(cardboy::sdk::IEventBus* bus) { _eventBus = bus; }

Firmware/components/backend-esp/src/esp_backend.cpp

@@ -138,6 +138,7 @@ EspRuntime::EspRuntime() : framebuffer(), input(), clock() {
     highResClockService = std::make_unique<HighResClockService>();
     powerService        = std::make_unique<PowerService>();
     filesystemService   = std::make_unique<FilesystemService>();
+    eventBus            = std::make_unique<EventBus>();
 
     services.buzzer       = buzzerService.get();
     services.battery      = batteryService.get();
@@ -146,6 +147,9 @@ EspRuntime::EspRuntime() : framebuffer(), input(), clock() {
     services.highResClock = highResClockService.get();
     services.powerManager = powerService.get();
     services.filesystem   = filesystemService.get();
+    services.eventBus     = eventBus.get();
+
+    Buttons::get().setEventBus(eventBus.get());
 }
 
 EspRuntime::~EspRuntime() = default;

Firmware/components/backend-esp/src/event_bus.cpp

@@ -0,0 +1,81 @@
+#include "cardboy/backend/esp/event_bus.hpp"
+
+#include "cardboy/sdk/event_bus.hpp"
+
+#include "freertos/portmacro.h"
+
+#include <algorithm>
+
+namespace cardboy::backend::esp {
+
+namespace {
+[[nodiscard]] TickType_t toTicks(std::uint32_t timeout_ms) {
+    if (timeout_ms == cardboy::sdk::IEventBus::kWaitForever)
+        return portMAX_DELAY;
+    return pdMS_TO_TICKS(timeout_ms);
+}
+} // namespace
+
+static void timerCallback(TimerHandle_t handle) {
+    auto* bus = static_cast<EventBus*>(pvTimerGetTimerID(handle));
+    if (bus)
+        bus->signal(cardboy::sdk::to_event_bits(cardboy::sdk::EventBusSignal::Timer));
+}
+
+EventBus::EventBus() :
+    group(xEventGroupCreate()), timer(xTimerCreate("EventBusTimer", pdMS_TO_TICKS(1), pdFALSE, this, timerCallback)) {}
+
+EventBus::~EventBus() {
+    if (timer)
+        xTimerDelete(timer, portMAX_DELAY);
+    if (group)
+        vEventGroupDelete(group);
+}
+
+void EventBus::signal(std::uint32_t bits) {
+    if (!group || bits == 0)
+        return;
+    xEventGroupSetBits(group, bits);
+}
+
+void EventBus::signalFromISR(std::uint32_t bits) {
+    if (!group || bits == 0)
+        return;
+    BaseType_t higherPriorityTaskWoken = pdFALSE;
+    xEventGroupSetBitsFromISR(group, bits, &higherPriorityTaskWoken);
+    if (higherPriorityTaskWoken == pdTRUE)
+        portYIELD_FROM_ISR(higherPriorityTaskWoken);
+}
+
+std::uint32_t EventBus::wait(std::uint32_t mask, std::uint32_t timeout_ms) {
+    if (!group || mask == 0)
+        return 0;
+    const EventBits_t bits = xEventGroupWaitBits(group, mask, pdTRUE, pdFALSE, toTicks(timeout_ms));
+    return static_cast<std::uint32_t>(bits & mask);
+}
+
+void EventBus::scheduleTimerSignal(std::uint32_t delay_ms) {
+    if (!timer)
+        return;
+    xTimerStop(timer, 0);
+
+    if (delay_ms == cardboy::sdk::IEventBus::kWaitForever)
+        return;
+
+    if (delay_ms == 0) {
+        signal(cardboy::sdk::to_event_bits(cardboy::sdk::EventBusSignal::Timer));
+        return;
+    }
+
+    const TickType_t ticks = std::max<TickType_t>(pdMS_TO_TICKS(delay_ms), 1);
+    if (xTimerChangePeriod(timer, ticks, 0) == pdPASS)
+        xTimerStart(timer, 0);
+}
+
+void EventBus::cancelTimerSignal() {
+    if (!timer)
+        return;
+    xTimerStop(timer, 0);
+}
+
+} // namespace cardboy::backend::esp

Firmware/sdk/backend_interface/CMakeLists.txt

@@ -16,6 +16,7 @@ target_sources(cardboy_backend_interface
         ${CMAKE_CURRENT_SOURCE_DIR}/include/cardboy/backend/backend_interface.hpp
         ${CMAKE_CURRENT_SOURCE_DIR}/include/cardboy/sdk/backend.hpp
         ${CMAKE_CURRENT_SOURCE_DIR}/include/cardboy/sdk/display_spec.hpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/include/cardboy/sdk/event_bus.hpp
         ${CMAKE_CURRENT_SOURCE_DIR}/include/cardboy/sdk/input_state.hpp
         ${CMAKE_CURRENT_SOURCE_DIR}/include/cardboy/sdk/platform.hpp
         ${CMAKE_CURRENT_SOURCE_DIR}/include/cardboy/sdk/services.hpp

Firmware/sdk/backend_interface/include/cardboy/sdk/event_bus.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <cstdint>
+
+namespace cardboy::sdk {
+
+enum class EventBusSignal : std::uint32_t {
+    None     = 0,
+    Input    = 1u << 0,
+    Timer    = 1u << 1,
+    External = 1u << 2,
+};
+
+inline EventBusSignal operator|(EventBusSignal lhs, EventBusSignal rhs) {
+    return static_cast<EventBusSignal>(static_cast<std::uint32_t>(lhs) | static_cast<std::uint32_t>(rhs));
+}
+
+inline EventBusSignal& operator|=(EventBusSignal& lhs, EventBusSignal rhs) {
+    lhs = lhs | rhs;
+    return lhs;
+}
+
+inline EventBusSignal operator&(EventBusSignal lhs, EventBusSignal rhs) {
+    return static_cast<EventBusSignal>(static_cast<std::uint32_t>(lhs) & static_cast<std::uint32_t>(rhs));
+}
+
+inline std::uint32_t to_event_bits(EventBusSignal signal) { return static_cast<std::uint32_t>(signal); }
+
+class IEventBus {
+public:
+    static constexpr std::uint32_t kWaitForever = 0xFFFFFFFFu;
+
+    virtual ~IEventBus() = default;
+
+    virtual void          signal(std::uint32_t bits)                         = 0;
+    virtual void          signalFromISR(std::uint32_t bits)                  = 0;
+    virtual std::uint32_t wait(std::uint32_t mask, std::uint32_t timeout_ms) = 0;
+    virtual void          scheduleTimerSignal(std::uint32_t delay_ms)        = 0;
+    virtual void          cancelTimerSignal()                                = 0;
+};
+
+} // namespace cardboy::sdk

Firmware/sdk/backend_interface/include/cardboy/sdk/services.hpp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "cardboy/sdk/event_bus.hpp"
+
 #include <cstdint>
 #include <string>
 #include <string_view>
@@ -82,6 +84,7 @@ struct Services {
     IHighResClock*   highResClock = nullptr;
     IPowerManager*   powerManager = nullptr;
     IFilesystem*     filesystem   = nullptr;
+    IEventBus*       eventBus     = nullptr;
 };
 
 } // namespace cardboy::sdk

Firmware/sdk/backends/desktop/include/cardboy/backend/desktop_backend.hpp

@@ -1,14 +1,17 @@
 #pragma once
 
+#include "cardboy/sdk/event_bus.hpp"
 #include "cardboy/sdk/platform.hpp"
 #include "cardboy/sdk/services.hpp"
 
 #include <SFML/Graphics.hpp>
 #include <SFML/Window/Keyboard.hpp>
 #include <chrono>
+#include <condition_variable>
 #include <cstdint>
 #include <filesystem>
 #include <limits>
+#include <mutex>
 #include <random>
 #include <string>
 #include <string_view>
@@ -92,6 +95,29 @@ private:
     bool                  mounted = false;
 };
 
+class DesktopEventBus final : public cardboy::sdk::IEventBus {
+public:
+    explicit DesktopEventBus(DesktopRuntime& owner);
+    ~DesktopEventBus() override;
+
+    void          signal(std::uint32_t bits) override;
+    void          signalFromISR(std::uint32_t bits) override;
+    std::uint32_t wait(std::uint32_t mask, std::uint32_t timeout_ms) override;
+    void          scheduleTimerSignal(std::uint32_t delay_ms) override;
+    void          cancelTimerSignal() override;
+
+private:
+    DesktopRuntime&         runtime;
+    std::mutex              mutex;
+    std::condition_variable cv;
+    std::uint32_t           pendingBits = 0;
+
+    std::mutex              timerMutex;
+    std::condition_variable timerCv;
+    std::thread             timerThread;
+    bool                    timerCancel = false;
+};
+
 class DesktopFramebuffer final : public cardboy::sdk::FramebufferFacade<DesktopFramebuffer> {
 public:
     explicit DesktopFramebuffer(DesktopRuntime& runtime);
@@ -170,6 +196,7 @@ private:
     DesktopHighResClock    highResService;
     DesktopPowerManager    powerService;
     DesktopFilesystem      filesystemService;
+    DesktopEventBus        eventBusService;
     cardboy::sdk::Services services{};
 };
 

Firmware/sdk/backends/desktop/src/desktop_backend.cpp

@@ -13,6 +13,92 @@
 
 namespace cardboy::backend::desktop {
 
+DesktopEventBus::DesktopEventBus(DesktopRuntime& owner) : runtime(owner) {}
+
+DesktopEventBus::~DesktopEventBus() { cancelTimerSignal(); }
+
+void DesktopEventBus::signal(std::uint32_t bits) {
+    if (bits == 0)
+        return;
+    {
+        std::lock_guard<std::mutex> lock(mutex);
+        pendingBits |= bits;
+    }
+    cv.notify_all();
+}
+
+void DesktopEventBus::signalFromISR(std::uint32_t bits) { signal(bits); }
+
+std::uint32_t DesktopEventBus::wait(std::uint32_t mask, std::uint32_t timeout_ms) {
+    if (mask == 0)
+        return 0;
+
+    const auto start    = std::chrono::steady_clock::now();
+    const bool infinite = timeout_ms == cardboy::sdk::IEventBus::kWaitForever;
+
+    while (true) {
+        {
+            std::lock_guard<std::mutex> lock(mutex);
+            const std::uint32_t         ready = pendingBits & mask;
+            if (ready != 0) {
+                pendingBits &= ~mask;
+                return ready;
+            }
+        }
+
+        if (!infinite) {
+            const auto now       = std::chrono::steady_clock::now();
+            const auto elapsedMs = std::chrono::duration_cast<std::chrono::milliseconds>(now - start).count();
+            if (elapsedMs >= static_cast<std::int64_t>(timeout_ms))
+                return 0;
+            const auto remaining = timeout_ms - static_cast<std::uint32_t>(elapsedMs);
+            runtime.sleepFor(std::min<std::uint32_t>(remaining, 8));
+        } else {
+            runtime.sleepFor(8);
+        }
+    }
+}
+
+void DesktopEventBus::scheduleTimerSignal(std::uint32_t delay_ms) {
+    cancelTimerSignal();
+
+    if (delay_ms == cardboy::sdk::IEventBus::kWaitForever)
+        return;
+
+    if (delay_ms == 0) {
+        signal(cardboy::sdk::to_event_bits(cardboy::sdk::EventBusSignal::Timer));
+        return;
+    }
+
+    {
+        std::lock_guard<std::mutex> lock(timerMutex);
+        timerCancel = false;
+    }
+
+    timerThread = std::thread([this, delay_ms]() {
+        std::unique_lock<std::mutex> lock(timerMutex);
+        const bool                   cancelled =
+                timerCv.wait_for(lock, std::chrono::milliseconds(delay_ms), [this] { return timerCancel; });
+        lock.unlock();
+        if (!cancelled)
+            signal(cardboy::sdk::to_event_bits(cardboy::sdk::EventBusSignal::Timer));
+    });
+}
+
+void DesktopEventBus::cancelTimerSignal() {
+    {
+        std::lock_guard<std::mutex> lock(timerMutex);
+        timerCancel = true;
+    }
+    timerCv.notify_all();
+    if (timerThread.joinable())
+        timerThread.join();
+    {
+        std::lock_guard<std::mutex> lock(timerMutex);
+        timerCancel = false;
+    }
+}
+
 bool DesktopStorage::readUint32(std::string_view ns, std::string_view key, std::uint32_t& out) {
     auto it = data.find(composeKey(ns, key));
     if (it == data.end())
@@ -90,6 +176,7 @@ DesktopInput::DesktopInput(DesktopRuntime& runtime) : runtime(runtime) {}
 cardboy::sdk::InputState DesktopInput::readState_impl() { return state; }
 
 void DesktopInput::handleKey(sf::Keyboard::Key key, bool pressed) {
+    bool handled = true;
     switch (key) {
         case sf::Keyboard::Key::Up:
             state.up = pressed;
@@ -118,8 +205,11 @@ void DesktopInput::handleKey(sf::Keyboard::Key key, bool pressed) {
             state.start = pressed;
             break;
         default:
+            handled = false;
             break;
     }
+    if (handled)
+        runtime.eventBusService.signal(cardboy::sdk::to_event_bits(cardboy::sdk::EventBusSignal::Input));
 }
 
 DesktopClock::DesktopClock(DesktopRuntime& runtime) : runtime(runtime), start(std::chrono::steady_clock::now()) {}
@@ -137,7 +227,7 @@ DesktopRuntime::DesktopRuntime() :
            "Cardboy Desktop"),
     texture(), sprite(texture),
     pixels(static_cast<std::size_t>(cardboy::sdk::kDisplayWidth * cardboy::sdk::kDisplayHeight) * 4, 0),
-    framebuffer(*this), input(*this), clock(*this) {
+    framebuffer(*this), input(*this), clock(*this), eventBusService(*this) {
     window.setFramerateLimit(60);
     if (!texture.resize(sf::Vector2u{cardboy::sdk::kDisplayWidth, cardboy::sdk::kDisplayHeight}))
         throw std::runtime_error("Failed to allocate texture for desktop framebuffer");
@@ -153,6 +243,7 @@ DesktopRuntime::DesktopRuntime() :
     services.highResClock = &highResService;
     services.powerManager = &powerService;
     services.filesystem   = &filesystemService;
+    services.eventBus     = &eventBusService;
 }
 
 cardboy::sdk::Services& DesktopRuntime::serviceRegistry() { return services; }

Firmware/sdk/core/include/cardboy/sdk/app_framework.hpp

@@ -63,6 +63,7 @@ struct AppContext {
     [[nodiscard]] IHighResClock*   highResClock() const { return services ? services->highResClock : nullptr; }
     [[nodiscard]] IPowerManager*   powerManager() const { return services ? services->powerManager : nullptr; }
     [[nodiscard]] IFilesystem*     filesystem() const { return services ? services->filesystem : nullptr; }
+    [[nodiscard]] IEventBus*       eventBus() const { return services ? services->eventBus : nullptr; }
 
     void requestAppSwitchByIndex(std::size_t index) {
         pendingAppIndex = index;

Firmware/sdk/core/include/cardboy/sdk/app_system.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cardboy/sdk/event_bus.hpp>
 #include "app_framework.hpp"
 
 #include <cstdint>
@@ -51,6 +52,7 @@ private:
     void          clearTimersForCurrentApp();
     TimerRecord*  findTimer(AppTimerHandle handle);
     bool          handlePendingSwitchRequest();
+    void          notifyEventBus(EventBusSignal signal);
 
     AppContext                                context;
     std::vector<std::unique_ptr<IAppFactory>> factories;

Firmware/sdk/core/src/app_system.cpp

@@ -17,8 +17,6 @@ namespace {
     return state.up || state.down || state.left || state.right || state.a || state.b || state.select || state.start;
 }
 
-constexpr std::uint32_t kIdlePollMs = 16;
-
 template<typename Framebuffer>
 void statusBarPreSendHook(void* framebuffer, void* userData) {
     auto* fb     = static_cast<Framebuffer*>(framebuffer);
@@ -127,13 +125,19 @@ void AppSystem::run() {
         if (waitMs == 0)
             continue;
 
-        if (waitMs == std::numeric_limits<std::uint32_t>::max())
-            waitMs = kIdlePollMs;
-        else
-            waitMs = std::min(waitMs, kIdlePollMs);
+        auto* eventBus = context.eventBus();
+        if (!eventBus)
+            return;
 
-        if (waitMs > 0)
-            context.clock.sleep_ms(waitMs);
+        const std::uint32_t mask = to_event_bits(EventBusSignal::Input) | to_event_bits(EventBusSignal::Timer);
+
+        if (waitMs == std::numeric_limits<std::uint32_t>::max()) {
+            eventBus->cancelTimerSignal();
+            eventBus->wait(mask, IEventBus::kWaitForever);
+        } else {
+            eventBus->scheduleTimerSignal(waitMs);
+            eventBus->wait(mask, IEventBus::kWaitForever);
+        }
     }
 }
 
@@ -167,24 +171,32 @@ AppTimerHandle AppSystem::scheduleTimer(std::uint32_t delay_ms, bool repeat) {
     record.repeat      = repeat;
     record.active      = true;
     timers.push_back(record);
+    notifyEventBus(EventBusSignal::Timer);
     return record.id;
 }
 
 void AppSystem::cancelTimer(AppTimerHandle handle) {
     auto* timer = findTimer(handle);
-    if (timer)
-        timer->active = false;
+    if (!timer)
+        return;
+    timer->active = false;
     timers.erase(std::remove_if(timers.begin(), timers.end(), [](const TimerRecord& rec) { return !rec.active; }),
                  timers.end());
+    notifyEventBus(EventBusSignal::Timer);
 }
 
 void AppSystem::cancelAllTimers() {
+    bool changed = false;
     for (auto& timer: timers) {
-        if (timer.generation == currentGeneration)
+        if (timer.generation == currentGeneration && timer.active) {
             timer.active = false;
+            changed      = true;
+        }
     }
     timers.erase(std::remove_if(timers.begin(), timers.end(), [](const TimerRecord& rec) { return !rec.active; }),
                  timers.end());
+    if (changed)
+        notifyEventBus(EventBusSignal::Timer);
 }
 
 void AppSystem::dispatchEvent(const AppEvent& event) {
@@ -229,8 +241,11 @@ std::uint32_t AppSystem::nextTimerDueMs(std::uint32_t now) const {
 }
 
 void AppSystem::clearTimersForCurrentApp() {
+    const bool hadTimers = !timers.empty();
     ++currentGeneration;
     timers.clear();
+    if (hadTimers)
+        notifyEventBus(EventBusSignal::Timer);
 }
 
 AppSystem::TimerRecord* AppSystem::findTimer(AppTimerHandle handle) {
@@ -260,4 +275,11 @@ bool AppSystem::handlePendingSwitchRequest() {
     return switched;
 }
 
+void AppSystem::notifyEventBus(EventBusSignal signal) {
+    if (signal == EventBusSignal::None)
+        return;
+    if (auto* bus = context.eventBus())
+        bus->signal(to_event_bits(signal));
+}
+
 } // namespace cardboy::sdk