engine_control/source/firmware/kernel/ringbuffer.c
2016-07-23 07:59:54 +02:00

65 lines
1.4 KiB
C
Executable File

/*
* ringbuffer.c
*
* Created on: Jul 24, 2012
* Author: tkl
*/
#include "irq.h"
#include "ringbuffer.h"
//-----------------------------------------------------------------------------
int ringbuffer_read(struct ringbuffer *this, char *buffer, int size) {
int i;
unsigned int irq;
for(i = 0; i < size; i++) {
if(this->used > 0) {
irq = disable_irq();
buffer[i] = *this->read;
this->read++;
this->used--;
if(this->read >= (this->buffer + this->size)) {
this->read = this->buffer;
}
restore_irq(irq);
}
else {
return i;
}
}
return 0;
}
//-----------------------------------------------------------------------------
int ringbuffer_write(struct ringbuffer *this, const char *buffer,
int size)
{
int i = 0;
unsigned int irq;
for(i = 0; i < size; i++) {
if(this->used < this->size) {
irq = disable_irq();
*this->write = buffer[i];
this->write++;
this->used++;
if(this->write >= (this->buffer + this->size)) {
this->write = this->buffer;
}
restore_irq(irq);
}
else {
return i;
}
}
return i;
}
//-----------------------------------------------------------------------------
int ringbuffer_is_full(const struct ringbuffer *this) {
return (this->used == this->size) ? 1 : 0;
}
//-----------------------------------------------------------------------------
int ringbuffer_is_empty(const struct ringbuffer *this) {
return (this->used == 0) ? 1 : 0;
}