Function attach_external_handler

src/platforms/esp/32/isr_esp32_idf3.hpp:325–412

}

inline int attach_external_handler(u8 pin, const isr_config_t& config, isr_handle_t* out_handle) FL_NOEXCEPT {
    if (!config.handler) {
        ESP_LOGW(ESP32_IDF3_ISR_TAG, "attachExternalHandler: handler is null");
        return -1;  // Invalid parameter
    }

    // Allocate handle data
    auto handle_owner = fl::make_unique<esp32_idf3_isr_handle_data>();
    auto* handle_data = handle_owner.get();
    if (!handle_data) {
        ESP_LOGW(ESP32_IDF3_ISR_TAG, "attachExternalHandler: failed to allocate handle data");
        return -3;  // Out of memory
    }

    handle_data->is_timer = false;
    handle_data->user_handler = config.handler;
    handle_data->user_data = config.user_data;

    // Configure GPIO
    gpio_config_t io_conf = {};
    io_conf.pin_bit_mask = (1ULL << pin);
    io_conf.mode = GPIO_MODE_INPUT;
    io_conf.pull_up_en = GPIO_PULLUP_DISABLE;
    io_conf.pull_down_en = GPIO_PULLDOWN_DISABLE;

    // Set interrupt type based on flags
    if (config.flags & isr::ISR_FLAG_EDGE_RISING) {
        io_conf.intr_type = GPIO_INTR_POSEDGE;
    } else if (config.flags & isr::ISR_FLAG_EDGE_FALLING) {
        io_conf.intr_type = GPIO_INTR_NEGEDGE;
    } else if (config.flags & isr::ISR_FLAG_LEVEL_HIGH) {
        io_conf.intr_type = GPIO_INTR_HIGH_LEVEL;
    } else if (config.flags & isr::ISR_FLAG_LEVEL_LOW) {
        io_conf.intr_type = GPIO_INTR_LOW_LEVEL;
    } else {
        // Default to any edge
        io_conf.intr_type = GPIO_INTR_ANYEDGE;
    }

    esp_err_t ret = gpio_config(&io_conf);
    if (ret != ESP_OK) {
        ESP_LOGW(ESP32_IDF3_ISR_TAG, "attachExternalHandler: gpio_config failed: %s", esp_err_to_name(ret));
        return -9;  // GPIO config failed
    }

    // Install GPIO ISR service if not already installed
    // Use critical section for multi-core safety
    static bool gpio_isr_service_installed = false;
    if (!gpio_isr_service_installed) {
        portENTER_CRITICAL(&gpio_isr_service_mutex_idf3);
        // Double-check after acquiring lock (classic double-checked locking pattern)
        if (!gpio_isr_service_installed) {
            ret = gpio_install_isr_service(0);
            if (ret != ESP_OK && ret != ESP_ERR_INVALID_STATE) {
                portEXIT_CRITICAL(&gpio_isr_service_mutex_idf3);
                ESP_LOGW(ESP32_IDF3_ISR_TAG, "attachExternalHandler: gpio_install_isr_service failed: %s", esp_err_to_name(ret));
                return -10;  // ISR service installation failed
            }