-/*!
+/**
* \file
* <!--
- * Copyright 2003,2004 Develer S.r.l. (http://www.develer.com/)
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction. Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License. This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * 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 $Id$
*
* \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.
+ * \li \c begin points to the first buffer element;
+ * \li \c end points to the last buffer element (unlike the STL convention);
+ * \li \c head points to the element to be extracted next;
+ * \li \c tail points to the location following the last insertion;
+ * \li when any of the pointers advances beyond \c end, it is reset
+ * back to \c begin.
*
* \code
*
* +-----------------------------------+
- * | vuoto | dati validi | vuoto |
+ * | empty | valid data | empty |
* +-----------------------------------+
* ^ ^ ^ ^
* begin head tail end
*
* \endcode
*
- * Il buffer e' VUOTO quando head e tail coincidono:
+ * The buffer is EMPTY when \c head and \c tail point to the same location:
* \code head == tail \endcode
*
- * Il buffer e' PIENO quando tail si trova immediatamente dietro a head:
+ * The buffer is FULL when \c tail points to the location immediately
+ * after \c head:
* \code tail == head - 1 \endcode
*
- * Il buffer e' PIENO anche quando tail e' posizionato
- * sull'ultima posizione del buffer e head sulla prima:
+ * The buffer is also FULL when \c tail points to the last buffer
+ * location and head points to the first one:
* \code head == begin && tail == end \endcode
*/
-/*
- * $Log$
- * Revision 1.4 2004/06/06 16:11:17 bernie
- * Protect MetroWerks specific pragmas with #ifdef's
- *
- * 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"
+#include <cpu/types.h>
+#include <cpu/irq.h>
+#include <cfg/debug.h>
typedef struct FIFOBuffer
{
} 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);
-#ifdef __MWERKS__
-#pragma interrupt called
-#endif
-INLINE void fifo_push(FIFOBuffer *fb, unsigned char c);
-#ifdef __MWERKS__
-#pragma interrupt called
-#endif
-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);
+#define ASSERT_VALID_FIFO(fifo) \
+ ATOMIC( \
+ ASSERT((fifo)->head >= (fifo)->begin); \
+ ASSERT((fifo)->head <= (fifo)->end); \
+ ASSERT((fifo)->tail >= (fifo)->begin); \
+ ASSERT((fifo)->tail <= (fifo)->end); \
+ )
-/*!
+/**
* 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.
+ * only if the CPU can atomically update a pointer
+ * (which the AVR and other 8-bit processors can't do).
+ *
+ * \sa fifo_isempty_locked
*/
INLINE bool fifo_isempty(const FIFOBuffer *fb)
{
+ //ASSERT_VALID_FIFO(fb);
return fb->head == fb->tail;
}
-/*!
+/**
* Check whether the fifo is full
*
* \note Calling fifo_isfull() is safe while a concurrent
*/
INLINE bool fifo_isfull(const FIFOBuffer *fb)
{
+ //ASSERT_VALID_FIFO(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.
+/**
+ * Push a character on 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.
+ * concurrent contexts, unless the CPU can't update
+ * a pointer atomically (which the AVR and other 8-bit
+ * processors can't do).
+ *
+ * \sa fifo_push_locked
*/
INLINE void fifo_push(FIFOBuffer *fb, unsigned char c)
{
+#ifdef __MWERKS__
+#pragma interrupt called
+#endif
+ //ASSERT_VALID_FIFO(fb);
+
/* Write at tail position */
*(fb->tail) = c;
- if (fb->tail == fb->end)
+ if (UNLIKELY(fb->tail == fb->end))
/* wrap tail around */
fb->tail = fb->begin;
else
}
-/*!
+/**
* Pop a character from the fifo buffer.
*
* \note Calling \c fifo_pop() on an empty buffer is undefined.
*/
INLINE unsigned char fifo_pop(FIFOBuffer *fb)
{
- if (fb->head == fb->end)
+#ifdef __MWERKS__
+#pragma interrupt called
+#endif
+ //ASSERT_VALID_FIFO(fb);
+
+ if (UNLIKELY(fb->head == fb->end))
{
/* wrap head around */
fb->head = fb->begin;
}
-/*!
+/**
* Make the fifo empty, discarding all its current contents.
*/
INLINE void fifo_flush(FIFOBuffer *fb)
{
+ //ASSERT_VALID_FIFO(fb);
fb->head = fb->tail;
}
-/*!
+#if CPU_REG_BITS >= CPU_BITS_PER_PTR
+
+ /*
+ * 16/32bit CPUs that can update a pointer with a single write
+ * operation, no need to disable interrupts.
+ */
+ #define fifo_isempty_locked(fb) fifo_isempty((fb))
+ #define fifo_push_locked(fb, c) fifo_push((fb), (c))
+ #define fifo_pop_locked(fb) fifo_pop((fb))
+ #define fifo_flush_locked(fb) fifo_flush((fb))
+
+#else /* CPU_REG_BITS < CPU_BITS_PER_PTR */
+
+ /**
+ * Similar to fifo_isempty(), but with stronger guarantees for
+ * concurrent access between user and interrupt code.
+ *
+ * \note This is actually only needed for 8-bit processors.
+ *
+ * \sa fifo_isempty()
+ */
+ INLINE bool fifo_isempty_locked(const FIFOBuffer *fb)
+ {
+ bool result;
+ ATOMIC(result = fifo_isempty(fb));
+ return result;
+ }
+
+
+ /**
+ * Similar to fifo_push(), but with stronger guarantees for
+ * concurrent access between user and interrupt code.
+ *
+ * \note This is actually only needed for 8-bit processors.
+ *
+ * \sa fifo_push()
+ */
+ INLINE void fifo_push_locked(FIFOBuffer *fb, unsigned char c)
+ {
+ ATOMIC(fifo_push(fb, c));
+ }
+
+ /* Probably not really needed, but hard to prove. */
+ INLINE unsigned char fifo_pop_locked(FIFOBuffer *fb)
+ {
+ unsigned char c;
+ ATOMIC(c = fifo_pop(fb));
+ return c;
+ }
+
+ /**
+ * Similar to fifo_flush(), but with stronger guarantees for
+ * concurrent access between user and interrupt code.
+ *
+ * \note This is actually only needed for 8-bit processors.
+ *
+ * \sa fifo_flush()
+ */
+ INLINE void fifo_flush_locked(FIFOBuffer *fb)
+ {
+ ATOMIC(fifo_flush(fb));
+ }
+
+#endif /* CPU_REG_BITS < BITS_PER_PTR */
+
+
+/**
+ * Thread safe version of fifo_isfull()
+ */
+INLINE bool fifo_isfull_locked(const FIFOBuffer *_fb)
+{
+ bool result;
+ ATOMIC(result = fifo_isfull(_fb));
+ return result;
+}
+
+
+/**
* FIFO Initialization.
*/
INLINE void fifo_init(FIFOBuffer *fb, unsigned char *buf, size_t size)
{
+ /* FIFO buffers have a known bug with 1-byte buffers. */
+ ASSERT(size > 1);
+
fb->head = fb->tail = fb->begin = buf;
fb->end = buf + size - 1;
}
-
#if 0
/*
projects / bertos.git / blobdiff