ardupilot/libraries/AP_HAL_AVR_SITL/UARTDriver.h

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-

#ifndef __AP_HAL_AVR_SITL_UART_DRIVER_H__
#define __AP_HAL_AVR_SITL_UART_DRIVER_H__
#include <AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL

#include <stdint.h>
#include <stdarg.h>
#include "AP_HAL_AVR_SITL_Namespace.h"

class AVR_SITL::SITLUARTDriver : public AP_HAL::UARTDriver {
public:
    friend class AVR_SITL::SITL_State;

	SITLUARTDriver(const uint8_t portNumber, SITL_State *sitlState) {
		_portNumber = portNumber;
        _rxSpace = _default_rx_buffer_size;
        _txSpace = _default_tx_buffer_size;
        _sitlState = sitlState;
        
        _fd = -1;
        _listen_fd = -1;
	}

    /* Implementations of UARTDriver virtual methods */
    void begin(uint32_t b) { begin(b, 0, 0); }
    void begin(uint32_t b, uint16_t rxS, uint16_t txS);
    void end();
    void flush();
    bool is_initialized() { return true; }

    void set_blocking_writes(bool blocking) 
    {
		_nonblocking_writes = !blocking;
    }

    bool tx_pending() {
	    return false;
    }

    /* Implementations of Stream virtual methods */
    int16_t available();
    int16_t txspace();
    int16_t read();

    /* Implementations of Print virtual methods */
    size_t write(uint8_t c);

    // file descriptor, exposed so SITL_State::loop_hook() can use it
	int _fd;

private:
    uint8_t _portNumber;
	bool _connected; // true if a client has connected
	int _listen_fd;  // socket we are listening on
	int _serial_port;
	static bool _console;
	bool _nonblocking_writes;
    uint16_t _rxSpace;
    uint16_t _txSpace;

    void _tcp_start_connection(bool wait_for_connection);
    void _check_connection(void);
    static bool _select_check(int );
    static void _set_nonblocking(int );

	/// default receive buffer size
	static const uint16_t _default_rx_buffer_size = 128;

	/// default transmit buffer size
	static const uint16_t _default_tx_buffer_size = 16;

	/// maxium tx/rx buffer size
	/// @note if we could bring the max size down to 256, the mask and head/tail
	///       pointers in the buffer could become uint8_t.
	///
	static const uint16_t _max_buffer_size = 512;

    SITL_State *_sitlState;

};

#endif
#endif // __AP_HAL_AVR_SITL_UART_DRIVER_H__