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#ifndef FIFO_H
#define FIFO_H
#include "lwip/sys.h"
/** How many bytes in fifo */
#define FIFOSIZE 2048
/** fifo data structure, this one is passed to all fifo functions */
typedef struct fifo_t {
u8_t data[FIFOSIZE+10]; /* data segment, +10 is a hack probably not needed.. FIXME! */
int dataslot; /* index to next char to be read */
int emptyslot; /* index to next empty slot */
int len; /* len probably not needed, may be calculated from dataslot and emptyslot in conjunction with FIFOSIZE */
sys_sem_t sem; /* semaphore protecting simultaneous data manipulation */
sys_sem_t getSem; /* sepaphore used to signal new data if getWaiting is set */
u8_t getWaiting; /* flag used to indicate that fifoget is waiting for data. fifoput is suposed to clear */
/* this flag prior to signaling the getSem semaphore */
} fifo_t;
/**
* Get a character from fifo
* Blocking call.
* @param fifo pointer to fifo data structure
* @return character read from fifo
*/
u8_t fifoGet(fifo_t * fifo);
/**
* Get a character from fifo
* Non blocking call.
* @param fifo pointer to fifo data structure
* @return character read from fifo, or < zero if non was available
*/
s16_t fifoGetNonBlock(fifo_t * fifo);
/**
* fifoput is called by the signalhandler when new data has arrived (or some other event is indicated)
* fifoput reads directly from the serialport and is thus highly dependent on unix arch at this moment
* @param fifo pointer to fifo data structure
* @param fd unix file descriptor
*/
void fifoPut(fifo_t * fifo, int fd);
/**
* fifoinit initiate fifo
* @param fifo pointer to fifo data structure, allocated by the user
*/
void fifoInit(fifo_t * fifo);
#endif
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