Files
lib_xua/examples/xua_lite_example/src/fifo_impl.h
2018-10-26 16:24:50 +01:00

72 lines
2.1 KiB
C

#ifndef __FIFO__
#define __FIFO__
#include <string.h> //memcpy
#include "fifo_types.h"
//Asynch FIFO implementaion
//Note these are in the include file to allow the compiler to inline for performance
///////////////////////////////////////
//Shared memory FIFO (sample by sample)
//Can be any size
///////////////////////////////////////
static inline unsigned fifo_get_fill(volatile mem_fifo_t * unsafe fifo) {
unsafe{
unsigned fifo_fill = 0;
if (fifo->write_idx >= fifo->read_idx){
fifo_fill = fifo->write_idx - fifo->read_idx;
}
else{
fifo_fill = (fifo->size + fifo->write_idx) - fifo->read_idx;
}
return fifo_fill;
}
}
#pragma unsafe arrays
static inline fifo_ret_t fifo_block_push(volatile mem_fifo_t * unsafe fifo, int data[], unsigned n) {
unsafe{
//check there is a block of space large enough
unsigned space_remaining = fifo->size - fifo_get_fill(fifo) - 1;
if (n > space_remaining) {
return FIFO_FULL;
}
for (int i = 0; i < n; i++){
unsigned next_idx = fifo->write_idx + 1;
if (next_idx == fifo->size) next_idx = 0; //Check for wrap
fifo->data_base_ptr[fifo->write_idx] = data[i];
fifo->write_idx = next_idx;
}
return FIFO_SUCCESS;
}
}
#pragma unsafe arrays
static inline fifo_ret_t fifo_block_pop(volatile mem_fifo_t * unsafe fifo, int data[], unsigned n) {
unsafe{
//Check we have a block big enough to send
if (n > fifo_get_fill(fifo)){
return FIFO_EMPTY;
}
for (int i = 0; i < n; i++){
data[i] = fifo->data_base_ptr[fifo->read_idx];
fifo->read_idx++;
if (fifo->read_idx == fifo->size) fifo->read_idx = 0; //Check for wrap
}
return FIFO_SUCCESS;
}
}
//Version of above that returns fill level relative to half full
static inline int fifo_get_fill_relative_half(volatile mem_fifo_t * unsafe fifo){
unsafe{
int fifo_fill = (int)fifo_get_fill(fifo);
fifo_fill -= (fifo->size / 2);
return fifo_fill;
}
}
#endif