dispatcher.hpp

Go to the documentation of this file.

#pragma once
 
#include "aria/abi/export.hpp"
#include "aria/property_ops.hpp"  // IDelayedScheduler
#include <chrono>
#include <functional>
#include <memory>
#include <cstddef>
 
namespace aria::runtime {

class ARIA_RUNTIME_API IDispatcher : public ::aria::IDelayedScheduler {
public:
    ~IDispatcher() override = default;

    virtual void post(std::function<void()> fn) = 0;

    virtual void post_delayed(std::chrono::milliseconds delay, std::function<void()> fn) = 0;

    [[nodiscard]] bool is_main_thread() const noexcept override = 0;

    void post_after(std::chrono::milliseconds delay,
                    std::function<void()> fn) override {
        post_delayed(delay, std::move(fn));
    }
 
    // ── IScheduler bridge ────────────────────────────────────────────
    [[nodiscard]] ::aria::SchedulerCaps caps() const noexcept override {
        return ::aria::SchedulerCaps::Post
             | ::aria::SchedulerCaps::Delay
             | ::aria::SchedulerCaps::MainThread
             | ::aria::SchedulerCaps::Pumpable;
    }
    void schedule(std::function<void()> fn) override {
        post(std::move(fn));
    }
    void schedule_after(std::chrono::milliseconds delay,
                        std::function<void()> fn) override {
        post_delayed(delay, std::move(fn));
    }
};

ARIA_RUNTIME_API std::shared_ptr<IDispatcher> main_dispatcher();
ARIA_RUNTIME_API void set_main_dispatcher(std::shared_ptr<IDispatcher> dispatcher);

class ARIA_RUNTIME_API SimpleDispatcher : public IDispatcher {
public:
    SimpleDispatcher();
    ~SimpleDispatcher() override;
 
    SimpleDispatcher(const SimpleDispatcher&) = delete;
    SimpleDispatcher& operator=(const SimpleDispatcher&) = delete;
    SimpleDispatcher(SimpleDispatcher&&) = delete;
    SimpleDispatcher& operator=(SimpleDispatcher&&) = delete;
 
    void post(std::function<void()> fn) override;
    void post_delayed(std::chrono::milliseconds delay, std::function<void()> fn) override;
    [[nodiscard]] bool is_main_thread() const noexcept override;

    std::size_t pump(std::chrono::milliseconds budget = std::chrono::milliseconds{50});

    void run_one();
 
private:
    struct Impl;
    // RAII pImpl; C4251 on the shared_ptr member is a false positive for an
    // incomplete opaque pointee consumed only via non-template API.
#ifdef _MSC_VER
#  pragma warning(push)
#  pragma warning(disable: 4251)
#endif
    std::shared_ptr<Impl> impl_;
#ifdef _MSC_VER
#  pragma warning(pop)
#endif
};
 
}  // namespace aria::runtime