vt100/src/serial.h

/* One direction of an asynchronous serial line: 8 data bits, no parity, 1 stop bit, so a * character takes 10 bit times. A byte put on the line arrives when its last bit has. */#pragma once#include <stdbool.h>#include <stdint.h>#define SERIAL_BUF 32768typedef struct {  uint8_t buf[SERIAL_BUF];  unsigned head, tail; /* head: next to arrive, tail: next free */  double char_ms;      /* 0 = infinitely fast */  double busy_until;   /* when the character now on the wire has arrived */  bool paused;         /* flow control (XOFF): the sender stops after the current character */} serial_line;void serial_init(serial_line *l, int baud);bool serial_put(serial_line *l, uint8_t b, double now_ms);/* next byte that has arrived by now_ms, or -1 */int serial_get(serial_line *l, double now_ms);bool serial_empty(const serial_line *l);/* XOFF / XON */void serial_set_paused(serial_line *l, bool paused, double now_ms);