CS代考计算机代写 #include “devices/input.h”

#include “devices/input.h”
#include
#include “devices/intq.h”
#include “devices/serial.h”

/* Stores keys from the keyboard and serial port. */
static struct intq buffer;

/* Initializes the input buffer. */
void
input_init (void)
{
intq_init (&buffer);
}

/* Adds a key to the input buffer.
Interrupts must be off and the buffer must not be full. */
void
input_putc (uint8_t key)
{
ASSERT (intr_get_level () == INTR_OFF);
ASSERT (!intq_full (&buffer));

intq_putc (&buffer, key);
serial_notify ();
}

/* Retrieves a key from the input buffer.
If the buffer is empty, waits for a key to be pressed. */
uint8_t
input_getc (void)
{
enum intr_level old_level;
uint8_t key;

old_level = intr_disable ();
key = intq_getc (&buffer);
serial_notify ();
intr_set_level (old_level);

return key;
}

/* Returns true if the input buffer is full,
false otherwise.
Interrupts must be off. */
bool
input_full (void)
{
ASSERT (intr_get_level () == INTR_OFF);
return intq_full (&buffer);
}