mijin2/source/mijin/async/signal.hpp

154 lines
4.2 KiB
C++

#pragma once
#if !defined(MIJIN_ASYNC_SIGNAL_HPP_INCLUDED)
#define MIJIN_ASYNC_SIGNAL_HPP_INCLUDED 1
#include <algorithm>
#include <cstdint>
#include <functional>
#include <memory>
#include <mutex>
#include <vector>
#include "../internal/common.hpp"
#include "../util/flag.hpp"
namespace mijin
{
//
// public defines
//
//
// public constants
//
using signal_token_t = std::uint32_t;
inline constexpr signal_token_t INVALID_SIGNAL_TOKEN = std::numeric_limits<signal_token_t>::max();
//
// public types
//
MIJIN_DEFINE_FLAG(Oneshot);
template<typename... TArgs>
class Signal
{
public:
using handler_t = std::function<void(TArgs...)>;
using token_t = signal_token_t;
private:
struct RegisteredHandler
{
handler_t callable;
std::weak_ptr<void> referenced;
token_t token;
Oneshot oneshot = Oneshot::NO;
};
using handler_vector_t = std::vector<RegisteredHandler>;
private:
handler_vector_t handlers_;
token_t nextToken = 1;
std::mutex handlersMutex_;
public:
Signal() = default;
Signal(const Signal&) = delete;
Signal(Signal&&) MIJIN_NOEXCEPT = default;
public:
Signal& operator=(const Signal&) = delete;
Signal& operator=(Signal&&) MIJIN_NOEXCEPT = default;
public:
template<typename THandler, typename TWeak = void>
inline token_t connect(THandler handler, Oneshot oneshot = Oneshot::NO, std::weak_ptr<TWeak> referenced = std::weak_ptr<TWeak>()) MIJIN_NOEXCEPT;
template<typename TObject, typename TWeak = void>
inline token_t connect(TObject& object, void (TObject::* handler)(TArgs...), Oneshot oneshot = Oneshot::NO, std::weak_ptr<TWeak> referenced = std::weak_ptr<TWeak>()) MIJIN_NOEXCEPT;
inline void disconnect(token_t token) MIJIN_NOEXCEPT;
inline void emit(TArgs&&... args) MIJIN_NOEXCEPT;
};
//
// public functions
//
template<typename... TArgs>
template<typename THandler, typename TWeak>
inline auto Signal<TArgs...>::connect(THandler handler, Oneshot oneshot, std::weak_ptr<TWeak> referenced) MIJIN_NOEXCEPT -> token_t
{
std::lock_guard lock(handlersMutex_);
auto callable = handler_t(handler);
handlers_.push_back({
.callable = std::move(callable),
.referenced = std::move(referenced),
.token = nextToken,
.oneshot = oneshot
});
return nextToken++;
}
template<typename... TArgs>
template<typename TObject, typename TWeak>
inline auto Signal<TArgs...>::connect(TObject& object, void (TObject::* handler)(TArgs...), Oneshot oneshot, std::weak_ptr<TWeak> referenced) MIJIN_NOEXCEPT -> token_t
{
std::lock_guard lock(handlersMutex_);
auto callable = [object = &object, handler](TArgs... args)
{
std::invoke(handler, object, std::forward<TArgs>(args)...);
};
handlers_.push_back({
.callable = std::move(callable),
.referenced = std::move(referenced),
.token = nextToken,
.oneshot = oneshot
});
return nextToken++;
}
template<typename... TArgs>
inline void Signal<TArgs...>::disconnect(token_t token) MIJIN_NOEXCEPT
{
std::lock_guard lock(handlersMutex_);
auto it = std::remove_if(handlers_.begin(), handlers_.end(), [token](const RegisteredHandler& handler)
{
return handler.token == token;
});
handlers_.erase(it, handlers_.end());
}
template<typename... TArgs>
inline void Signal<TArgs...>::emit(TArgs&&... args) MIJIN_NOEXCEPT
{
std::lock_guard lock(handlersMutex_);
// first erase any handlers with expired references
// auto it = std::remove_if(handlers_.begin(), handlers_.end(), [](const RegisteredHandler& handler)
// {
// return handler.referenced.expired();
// });
// handlers_.erase(it, handlers_.end());
// TODO: this doesn't really work since expired() also returns true if the pointer was never set
// invoke all handlers
for (RegisteredHandler& handler : handlers_)
{
handler.callable(std::forward<TArgs>(args)...);
}
// remove any oneshot
auto it = std::remove_if(handlers_.begin(), handlers_.end(), [](const RegisteredHandler& handler)
{
return handler.oneshot;
});
handlers_.erase(it, handlers_.end());
}
} // namespace mijin
#endif // !defined(MIJIN_ASYNC_SIGNAL_HPP_INCLUDED)