RS232Net.hh

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#ifndef RS232NET_HH
#define RS232NET_HH
 
#include "RS232Device.hh"
 
#include "EventListener.hh"
#include "StringSetting.hh"
#include "BooleanSetting.hh"
#include "Socket.hh"
 
#include "Poller.hh"
#include "circular_buffer.hh"
 
#include <atomic>
#include <mutex>
#include <span>
#include <thread>
#include <cstdint>
 
namespace openmsx {
 
class EventDistributor;
class Scheduler;
class CommandController;
 
class RS232Net final : public RS232Device, private EventListener
{
public:
        // opaque structure describing an address for use with socket functions
        struct NetworkSocketAddress {
                int domain; // the address family (AF_INET, ...)
                socklen_t len; // the length of the socket address
                union {
                        struct sockaddr generic;  // the generic type needed for calling the socket API
                        struct sockaddr_in ipv4;  // an IPv4 socket address
                        struct sockaddr_in6 ipv6; // an IPv6 socket address
                } address;
        };
 
public:
        RS232Net(EventDistributor& eventDistributor, Scheduler& scheduler,
                 CommandController& commandController);
        ~RS232Net() override;
 
        // Pluggable
        void plugHelper(Connector& connector, EmuTime::param time) override;
        void unplugHelper(EmuTime::param time) override;
        [[nodiscard]] std::string_view getName() const override;
        [[nodiscard]] std::string_view getDescription() const override;
 
        // input
        void signal(EmuTime::param time) override;
 
        // output
        void recvByte(uint8_t value, EmuTime::param time) override;
 
        [[nodiscard]] std::optional<bool> getDSR(EmuTime::param time) const override;
        [[nodiscard]] std::optional<bool> getCTS(EmuTime::param time) const override;
        [[nodiscard]] std::optional<bool> getDCD(EmuTime::param time) const override;
        [[nodiscard]] std::optional<bool> getRI(EmuTime::param time) const override;
        void setDTR(bool status, EmuTime::param time) override;
        void setRTS(bool status, EmuTime::param time) override;
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
private:
        void run(); // loop of helper thread that reads from 'sockfd'
 
        // EventListener
        int signalEvent(const Event& event) override;
 
        bool net_put(std::span<const char> buf);
        void open_socket(const NetworkSocketAddress& socket_address);
 
private:
        [[no_unique_address]] SocketActivator socketActivator;
        EventDistributor& eventDistributor;
        Scheduler& scheduler;
 
        // The value of these settings only matters at the time this device gets plugged in.
        // In other words: changing these settings only takes effect the next time the device gets plugged in.
        StringSetting rs232NetAddressSetting;
        BooleanSetting rs232NetUseIP232;
 
        std::thread thread; // receiving thread (reads from 'sockfd')
        std::mutex mutex; // to protect shared data between emulation and receiving thread
        Poller poller; // safe to use from main and receiver thread without extra locking
        cb_queue<char> queue; // read/written by both the main and the receiver thread. Must hold 'mutex' while doing so.
        std::atomic<SOCKET> sockfd; // read/written by both threads (use std::atomic as an alternative for locking)
 
        // These are written by the receiver thread and read by the main thread (use std::atomic as an alternative for locking)
        std::atomic<bool> DCD; // Data Carrier Detect input status
        std::atomic<bool> RI;  // Ring Indicator input status    TODO not yet used (write-only)
 
        // These are only accessed by the main thread (no need for locking)
        bool DTR; // Data Terminal Ready output status
        bool RTS; // Request To Send output status
 
        // This does not change while the receiving thread is running (no need for locking)
        bool IP232; // snapshot of 'rs232NetUseIP232' at the moment of plugging
};
 
} // namespace openmsx
 
#endif