Merge pull request #2994 from AnHardt/Inerrup-save-serial
Interrupt safe serial --- Guard against non-atomic variable changes from interrupt routines
This commit is contained in:
commit
f5972c4d2c
@ -33,16 +33,19 @@
|
|||||||
#endif
|
#endif
|
||||||
|
|
||||||
FORCE_INLINE void store_char(unsigned char c) {
|
FORCE_INLINE void store_char(unsigned char c) {
|
||||||
int i = (unsigned int)(rx_buffer.head + 1) % RX_BUFFER_SIZE;
|
CRITICAL_SECTION_START;
|
||||||
|
uint8_t h = rx_buffer.head;
|
||||||
|
uint8_t i = (uint8_t)(h + 1) & (RX_BUFFER_SIZE - 1);
|
||||||
|
|
||||||
// if we should be storing the received character into the location
|
// if we should be storing the received character into the location
|
||||||
// just before the tail (meaning that the head would advance to the
|
// just before the tail (meaning that the head would advance to the
|
||||||
// current location of the tail), we're about to overflow the buffer
|
// current location of the tail), we're about to overflow the buffer
|
||||||
// and so we don't write the character or advance the head.
|
// and so we don't write the character or advance the head.
|
||||||
if (i != rx_buffer.tail) {
|
if (i != rx_buffer.tail) {
|
||||||
rx_buffer.buffer[rx_buffer.head] = c;
|
rx_buffer.buffer[h] = c;
|
||||||
rx_buffer.head = i;
|
rx_buffer.head = i;
|
||||||
}
|
}
|
||||||
|
CRITICAL_SECTION_END;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
@ -101,24 +104,32 @@ void MarlinSerial::end() {
|
|||||||
|
|
||||||
|
|
||||||
int MarlinSerial::peek(void) {
|
int MarlinSerial::peek(void) {
|
||||||
if (rx_buffer.head == rx_buffer.tail) {
|
int v;
|
||||||
return -1;
|
CRITICAL_SECTION_START;
|
||||||
|
uint8_t t = rx_buffer.tail;
|
||||||
|
if (rx_buffer.head == t) {
|
||||||
|
v = -1;
|
||||||
}
|
}
|
||||||
else {
|
else {
|
||||||
return rx_buffer.buffer[rx_buffer.tail];
|
v = rx_buffer.buffer[t];
|
||||||
}
|
}
|
||||||
|
CRITICAL_SECTION_END;
|
||||||
|
return v;
|
||||||
}
|
}
|
||||||
|
|
||||||
int MarlinSerial::read(void) {
|
int MarlinSerial::read(void) {
|
||||||
// if the head isn't ahead of the tail, we don't have any characters
|
int v;
|
||||||
if (rx_buffer.head == rx_buffer.tail) {
|
CRITICAL_SECTION_START;
|
||||||
return -1;
|
uint8_t t = rx_buffer.tail;
|
||||||
|
if (rx_buffer.head == t) {
|
||||||
|
v = -1;
|
||||||
}
|
}
|
||||||
else {
|
else {
|
||||||
unsigned char c = rx_buffer.buffer[rx_buffer.tail];
|
v = rx_buffer.buffer[t];
|
||||||
rx_buffer.tail = (unsigned int)(rx_buffer.tail + 1) % RX_BUFFER_SIZE;
|
rx_buffer.tail = (uint8_t)(t + 1) & (RX_BUFFER_SIZE - 1);
|
||||||
return c;
|
|
||||||
}
|
}
|
||||||
|
CRITICAL_SECTION_END;
|
||||||
|
return v;
|
||||||
}
|
}
|
||||||
|
|
||||||
void MarlinSerial::flush() {
|
void MarlinSerial::flush() {
|
||||||
@ -131,7 +142,9 @@ void MarlinSerial::flush() {
|
|||||||
// the value to rx_buffer_tail; the previous value of rx_buffer_head
|
// the value to rx_buffer_tail; the previous value of rx_buffer_head
|
||||||
// may be written to rx_buffer_tail, making it appear as if the buffer
|
// may be written to rx_buffer_tail, making it appear as if the buffer
|
||||||
// were full, not empty.
|
// were full, not empty.
|
||||||
rx_buffer.head = rx_buffer.tail;
|
CRITICAL_SECTION_START;
|
||||||
|
rx_buffer.head = rx_buffer.tail;
|
||||||
|
CRITICAL_SECTION_END;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
@ -23,6 +23,12 @@
|
|||||||
#define MarlinSerial_h
|
#define MarlinSerial_h
|
||||||
#include "Marlin.h"
|
#include "Marlin.h"
|
||||||
|
|
||||||
|
#ifndef CRITICAL_SECTION_START
|
||||||
|
#define CRITICAL_SECTION_START unsigned char _sreg = SREG; cli();
|
||||||
|
#define CRITICAL_SECTION_END SREG = _sreg;
|
||||||
|
#endif
|
||||||
|
|
||||||
|
|
||||||
#ifndef SERIAL_PORT
|
#ifndef SERIAL_PORT
|
||||||
#define SERIAL_PORT 0
|
#define SERIAL_PORT 0
|
||||||
#endif
|
#endif
|
||||||
@ -69,13 +75,18 @@
|
|||||||
// using a ring buffer (I think), in which rx_buffer_head is the index of the
|
// using a ring buffer (I think), in which rx_buffer_head is the index of the
|
||||||
// location to which to write the next incoming character and rx_buffer_tail
|
// location to which to write the next incoming character and rx_buffer_tail
|
||||||
// is the index of the location from which to read.
|
// is the index of the location from which to read.
|
||||||
#define RX_BUFFER_SIZE 128
|
// 256 is the max limit due to uint8_t head and tail. Use only powers of 2. (...,16,32,64,128,256)
|
||||||
|
#ifndef RX_BUFFER_SIZE
|
||||||
|
#define RX_BUFFER_SIZE 128
|
||||||
|
#endif
|
||||||
|
#if !((RX_BUFFER_SIZE == 256) ||(RX_BUFFER_SIZE == 128) ||(RX_BUFFER_SIZE == 64) ||(RX_BUFFER_SIZE == 32) ||(RX_BUFFER_SIZE == 16) ||(RX_BUFFER_SIZE == 8) ||(RX_BUFFER_SIZE == 4) ||(RX_BUFFER_SIZE == 2))
|
||||||
|
#error RX_BUFFER_SIZE has to be a power of 2 and >= 2
|
||||||
|
#endif
|
||||||
|
|
||||||
struct ring_buffer {
|
struct ring_buffer {
|
||||||
unsigned char buffer[RX_BUFFER_SIZE];
|
unsigned char buffer[RX_BUFFER_SIZE];
|
||||||
int head;
|
volatile uint8_t head;
|
||||||
int tail;
|
volatile uint8_t tail;
|
||||||
};
|
};
|
||||||
|
|
||||||
#if UART_PRESENT(SERIAL_PORT)
|
#if UART_PRESENT(SERIAL_PORT)
|
||||||
@ -92,8 +103,12 @@ class MarlinSerial { //: public Stream
|
|||||||
int read(void);
|
int read(void);
|
||||||
void flush(void);
|
void flush(void);
|
||||||
|
|
||||||
FORCE_INLINE int available(void) {
|
FORCE_INLINE uint8_t available(void) {
|
||||||
return (unsigned int)(RX_BUFFER_SIZE + rx_buffer.head - rx_buffer.tail) % RX_BUFFER_SIZE;
|
CRITICAL_SECTION_START;
|
||||||
|
uint8_t h = rx_buffer.head;
|
||||||
|
uint8_t t = rx_buffer.tail;
|
||||||
|
CRITICAL_SECTION_END;
|
||||||
|
return (uint8_t)(RX_BUFFER_SIZE + h - t) & (RX_BUFFER_SIZE - 1);
|
||||||
}
|
}
|
||||||
|
|
||||||
FORCE_INLINE void write(uint8_t c) {
|
FORCE_INLINE void write(uint8_t c) {
|
||||||
@ -105,16 +120,19 @@ class MarlinSerial { //: public Stream
|
|||||||
FORCE_INLINE void checkRx(void) {
|
FORCE_INLINE void checkRx(void) {
|
||||||
if (TEST(M_UCSRxA, M_RXCx)) {
|
if (TEST(M_UCSRxA, M_RXCx)) {
|
||||||
unsigned char c = M_UDRx;
|
unsigned char c = M_UDRx;
|
||||||
int i = (unsigned int)(rx_buffer.head + 1) % RX_BUFFER_SIZE;
|
CRITICAL_SECTION_START;
|
||||||
|
uint8_t h = rx_buffer.head;
|
||||||
|
uint8_t i = (uint8_t)(h + 1) & (RX_BUFFER_SIZE - 1);
|
||||||
|
|
||||||
// if we should be storing the received character into the location
|
// if we should be storing the received character into the location
|
||||||
// just before the tail (meaning that the head would advance to the
|
// just before the tail (meaning that the head would advance to the
|
||||||
// current location of the tail), we're about to overflow the buffer
|
// current location of the tail), we're about to overflow the buffer
|
||||||
// and so we don't write the character or advance the head.
|
// and so we don't write the character or advance the head.
|
||||||
if (i != rx_buffer.tail) {
|
if (i != rx_buffer.tail) {
|
||||||
rx_buffer.buffer[rx_buffer.head] = c;
|
rx_buffer.buffer[h] = c;
|
||||||
rx_buffer.head = i;
|
rx_buffer.head = i;
|
||||||
}
|
}
|
||||||
|
CRITICAL_SECTION_END;
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
Loading…
Reference in New Issue
Block a user