fifo.c

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/**************************************************************************/
/**************************************************************************/
#include <string.h>
#include "fifo.h"

//static inline void mutex_lock   (fifo_t* f) ATTR_ALWAYS_INLINE;
//static inline void mutex_unlock (fifo_t* f) ATTR_ALWAYS_INLINE;
#define mutex_lock(f)
#define mutex_unlock(f)

static inline bool is_fifo_initalized(fifo_t* f) ATTR_ALWAYS_INLINE;


/**************************************************************************/
/**************************************************************************/
bool fifo_read(fifo_t* f, void * p_buffer)
{
  if( !is_fifo_initalized(f) || fifo_is_empty(f) )
  {
    return false;
  }

  mutex_lock(f);

  memcpy(p_buffer,
         f->buffer + (f->rd_idx * f->item_size),
         f->item_size);
  f->rd_idx = (f->rd_idx + 1) % f->depth;
  f->count--;

  mutex_unlock(f);

  return true;
}

/**************************************************************************/
/**************************************************************************/
bool fifo_write(fifo_t* f, void const * p_data)
{
  if ( !is_fifo_initalized(f) || (fifo_is_full(f) && !f->overwritable) )
  {
    return false;
  }

  mutex_lock(f);

  memcpy( f->buffer + (f->wr_idx * f->item_size),
          p_data,
          f->item_size);

  f->wr_idx = (f->wr_idx + 1) % f->depth;

  if (fifo_is_full(f))
  {
    f->rd_idx = f->wr_idx; // keep the full state (rd == wr && len = size)
  }else
  {
    f->count++;
  }

  mutex_unlock(f);

  return true;
}

/**************************************************************************/
/**************************************************************************/
void fifo_clear(fifo_t *f)
{
  mutex_lock(f);

  f->rd_idx = f->wr_idx = f->count = 0;

  mutex_unlock(f);
}

//--------------------------------------------------------------------+
// HELPER FUNCTIONS
//--------------------------------------------------------------------+

/**************************************************************************/
/**************************************************************************/
//static inline void mutex_lock (fifo_t* f)
//{
//  if (f->irq > 0)
//  {
//    #if !defined (_TEST_)
//    NVIC_DisableIRQ(f->irq);
//    #endif
//  }
//}

/**************************************************************************/
/**************************************************************************/
//static inline void mutex_unlock (fifo_t* f)
//{
//  if (f->irq > 0)
//  {
//    #if !defined (_TEST_)
//    NVIC_EnableIRQ(f->irq);
//    #endif
//  }
//}

static inline bool is_fifo_initalized(fifo_t* f)
{
  return !( f->buffer == NULL || f->depth == 0 || f->item_size == 0);
}