+++ /dev/null
-/*!
- * \file
- * <!--
- * Copyright 2003,2004 Develer S.r.l. (http://www.develer.com/)
- * Copyright 2001 Bernardo Innocenti <bernie@develer.com>
- * This file is part of DevLib - See devlib/README for information.
- * -->
- *
- * \version $Id$
- *
- * \author Bernardo Innocenti <bernie@develer.com>
- *
- * \brief General pourpose FIFO buffer implemented with a ring buffer
- *
- * \li \c begin punta al primo elemento del buffer,
- * \li \c end punta all'ultimo elemento,
- * \li \c head punta al prossimo elemento che verra' estratto,
- * \li \c tail punta alla posizione successiva all'ultimo elemento inserito.
- * \li quando uno dei due puntatori raggiunge @c end, viene resettato a @c begin.
- *
- * \code
- *
- * +-----------------------------------+
- * | vuoto | dati validi | vuoto |
- * +-----------------------------------+
- * ^ ^ ^ ^
- * begin head tail end
- *
- * \endcode
- *
- * Il buffer e' VUOTO quando head e tail coincidono:
- * \code head == tail \endcode
- *
- * Il buffer e' PIENO quando tail si trova immediatamente dietro a head:
- * \code tail == head - 1 \endcode
- *
- * Il buffer e' PIENO anche quando tail e' posizionato
- * sull'ultima posizione del buffer e head sulla prima:
- * \code head == begin && tail == end \endcode
- */
-
-/*
- * $Log$
- * Revision 1.3 2004/06/03 15:04:10 aleph
- * Merge improvements from project_ks (mainly inlining)
- *
- * Revision 1.2 2004/06/03 11:27:09 bernie
- * Add dual-license information.
- *
- * Revision 1.1 2004/05/23 15:43:16 bernie
- * Import mware modules.
- *
- * Revision 1.3 2004/05/22 17:55:58 rasky
- * \samp non esiste in doxygen
- *
- * Revision 1.2 2004/04/27 11:13:29 rasky
- * Spostate tutte le definizioni CPU-specific da compiler.h nel nuovo file cpu.h
- *
- * Revision 1.1 2004/04/21 17:38:25 rasky
- * New application
- *
- * Revision 1.4 2004/03/24 15:37:03 bernie
- * Remove Copyright messages from Doxygen output
- *
- * Revision 1.3 2004/03/18 18:11:07 bernie
- * Add thread-safe FIFO handling macros
- *
- * Revision 1.2 2004/03/01 08:00:36 bernie
- * Fixes for Doxygen
- *
- * Revision 1.1 2003/12/07 04:04:20 bernie
- * Initial project_ks framework.
- *
- * Revision 1.1 2003/11/21 16:36:17 aleph
- * Rename from fifo to fifobuf to avoid conflict with BSP fifo.h header
- *
- * Revision 1.1 2003/11/20 22:17:41 aleph
- * Add fifo buffer used by serial
- *
- */
-
-#ifndef MWARE_FIFO_H
-#define MWARE_FIFO_H
-
-#include "cpu.h"
-
-typedef struct FIFOBuffer
-{
- unsigned char * volatile head;
- unsigned char * volatile tail;
- unsigned char *begin;
- unsigned char *end;
-} FIFOBuffer;
-
-
-/* Public function prototypes */
-INLINE bool fifo_isempty(const FIFOBuffer *fb);
-INLINE bool fifo_isempty_locked(const FIFOBuffer *fb);
-INLINE bool fifo_isfull(const FIFOBuffer *fb);
-INLINE bool fifo_isfull_locked(const FIFOBuffer *fb);
-#pragma interrupt called
-INLINE void fifo_push(FIFOBuffer *fb, unsigned char c);
-#pragma interrupt called
-INLINE unsigned char fifo_pop(FIFOBuffer *fb);
-INLINE void fifo_flush(FIFOBuffer *fb);
-INLINE void fifo_init(FIFOBuffer *fb, unsigned char *buf, size_t size);
-
-
-/*!
- * Check whether the fifo is empty
- *
- * \note Calling fifo_isempty() is safe while a concurrent
- * execution context is calling fifo_push() or fifo_pop()
- * only if the CPU can atomically update a pointer.
- */
-INLINE bool fifo_isempty(const FIFOBuffer *fb)
-{
- return fb->head == fb->tail;
-}
-
-
-/*!
- * Check whether the fifo is full
- *
- * \note Calling fifo_isfull() is safe while a concurrent
- * execution context is calling fifo_pop() and the
- * CPU can update a pointer atomically.
- * It is NOT safe when the other context calls
- * fifo_push().
- * This limitation is not usually problematic in a
- * consumer/producer scenario because the
- * fifo_isfull() and fifo_push() are usually called
- * in the producer context.
- */
-INLINE bool fifo_isfull(const FIFOBuffer *fb)
-{
- return
- ((fb->head == fb->begin) && (fb->tail == fb->end))
- || (fb->tail == fb->head - 1);
-}
-
-
-#if !defined(__AVR__)
-
- /* No tricks needed on 16/32bit CPUs */
-# define fifo_isempty_locked(fb) fifo_isempty((fb))
-
-#else /* !__AVR__ */
-
- INLINE bool fifo_isempty_locked(const FIFOBuffer *fb)
- {
- bool result;
- cpuflags_t flags;
-
- DISABLE_IRQSAVE(flags);
- result = fifo_isempty(fb);
- ENABLE_IRQRESTORE(flags);
-
- return result;
- }
-
-#endif /* !__AVR__ */
-
-
-/*!
- * Thread safe version of fifo_isfull()
- */
-INLINE bool fifo_isfull_locked(const FIFOBuffer *_fb)
-{
- bool _result;
- cpuflags_t _flags;
-
- DISABLE_IRQSAVE(_flags);
- _result = fifo_isfull(_fb);
- ENABLE_IRQRESTORE(_flags);
-
- return _result;
-}
-
-
-/*!
- * Pop a character from the fifo buffer.
- *
- * \note Calling \c fifo_push() on a full buffer is undefined.
- * The caller must make sure the buffer has at least
- * one free slot before calling this function.
- *
- * \note It is safe to call fifo_pop() and fifo_push() from
- * concurrent contexts.
- */
-INLINE void fifo_push(FIFOBuffer *fb, unsigned char c)
-{
- /* Write at tail position */
- *(fb->tail) = c;
-
- if (fb->tail == fb->end)
- /* wrap tail around */
- fb->tail = fb->begin;
- else
- /* Move tail forward */
- fb->tail++;
-}
-
-
-/*!
- * Pop a character from the fifo buffer.
- *
- * \note Calling \c fifo_pop() on an empty buffer is undefined.
- * The caller must make sure the buffer contains at least
- * one character before calling this function.
- *
- * \note It is safe to call fifo_pop() and fifo_push() from
- * concurrent contexts.
- */
-INLINE unsigned char fifo_pop(FIFOBuffer *fb)
-{
- if (fb->head == fb->end)
- {
- /* wrap head around */
- fb->head = fb->begin;
- return *(fb->end);
- }
- else
- /* move head forward */
- return *(fb->head++);
-}
-
-
-/*!
- * Make the fifo empty, discarding all its current contents.
- */
-INLINE void fifo_flush(FIFOBuffer *fb)
-{
- fb->head = fb->tail;
-}
-
-
-/*!
- * FIFO Initialization.
- */
-INLINE void fifo_init(FIFOBuffer *fb, unsigned char *buf, size_t size)
-{
- fb->head = fb->tail = fb->begin = buf;
- fb->end = buf + size - 1;
-}
-
-
-
-#if 0
-
-/*
- * UNTESTED: if uncommented, to be moved in fifobuf.c
- */
-void fifo_pushblock(FIFOBuffer *fb, unsigned char *block, size_t len)
-{
- size_t freelen;
-
- /* Se c'e' spazio da tail alla fine del buffer */
- if (fb->tail >= fb->head)
- {
- freelen = fb->end - fb->tail + 1;
-
- /* C'e' abbastanza spazio per scrivere tutto il blocco? */
- if (freelen < len)
- {
- /* Scrivi quello che entra fino alla fine del buffer */
- memcpy(fb->tail, block, freelen);
- block += freelen;
- len -= freelen;
- fb->tail = fb->begin;
- }
- else
- {
- /* Scrivi tutto il blocco */
- memcpy(fb->tail, block, len);
- fb->tail += len;
- return;
- }
- }
-
- for(;;)
- {
- while (!(freelen = fb->head - fb->tail - 1))
- Delay(FIFO_POLLDELAY);
-
- /* C'e' abbastanza spazio per scrivere tutto il blocco? */
- if (freelen < len)
- {
- /* Scrivi quello che entra fino alla fine del buffer */
- memcpy(fb->tail, block, freelen);
- block += freelen;
- len -= freelen;
- fb->tail += freelen;
- }
- else
- {
- /* Scrivi tutto il blocco */
- memcpy(fb->tail, block, len);
- fb->tail += len;
- return;
- }
- }
-}
-#endif
-
-#endif /* MWARE_FIFO_H */
-
projects / bertos.git / blobdiff