* \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.
*
- * <pre>
+ * \code
*
* +-----------------------------------+
* | vuoto | dati validi | vuoto |
* ^ ^ ^ ^
* begin head tail end
*
- * </pre>
+ * \endcode
*
* Il buffer e' VUOTO quando head e tail coincidono:
* \code head == tail \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.
*
#define MWARE_FIFO_H
#include "cpu.h"
-#ifndef COMPILER_H
-#include "compiler.h"
-#endif
typedef struct FIFOBuffer
{
- unsigned char *head;
- unsigned char *tail;
+ unsigned char * volatile head;
+ unsigned char * volatile tail;
unsigned char *begin;
unsigned char *end;
} FIFOBuffer;
-/* Public function prototypes */
-void fifo_init(volatile FIFOBuffer *fb, unsigned char *buf, size_t size);
+/* 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
-void fifo_push(volatile FIFOBuffer *fb, unsigned char c);
-
+INLINE void fifo_push(FIFOBuffer *fb, unsigned char c);
#pragma interrupt called
-unsigned char fifo_pop(volatile FIFOBuffer *fb);
+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);
/*!
* execution context is calling fifo_push() or fifo_pop()
* only if the CPU can atomically update a pointer.
*/
-#define fifo_isempty(fb) ((fb)->head == (fb)->tail)
+INLINE bool fifo_isempty(const FIFOBuffer *fb)
+{
+ return fb->head == fb->tail;
+}
+
/*!
* Check whether the fifo is full
* fifo_isfull() and fifo_push() are usually called
* in the producer context.
*/
-#define fifo_isfull(fb) \
- ((((fb)->head == (fb)->begin) && ((fb)->tail == (fb)->end)) \
- || ((fb)->tail == (fb)->head - 1))
+INLINE bool fifo_isfull(const FIFOBuffer *fb)
+{
+ return
+ ((fb->head == fb->begin) && (fb->tail == fb->end))
+ || (fb->tail == fb->head - 1);
+}
-/*!
- * Make the fifo empty, discarding all its current contents.
- */
-#define fifo_flush(fb) ((fb)->head = (fb)->tail)
#if !defined(__AVR__)
#else /* !__AVR__ */
- INLINE bool fifo_isempty_locked(const volatile FIFOBuffer *_fb);
- INLINE bool fifo_isempty_locked(const volatile FIFOBuffer *_fb)
+ INLINE bool fifo_isempty_locked(const FIFOBuffer *fb)
{
- bool _result;
- cpuflags_t _flags;
+ bool result;
+ cpuflags_t flags;
- DISABLE_IRQSAVE(_flags);
- _result = fifo_isempty(_fb);
- ENABLE_IRQRESTORE(_flags);
+ DISABLE_IRQSAVE(flags);
+ result = fifo_isempty(fb);
+ ENABLE_IRQRESTORE(flags);
- return _result;
+ return result;
}
#endif /* !__AVR__ */
+
/*!
* Thread safe version of fifo_isfull()
*/
-INLINE bool fifo_isfull_locked(const volatile FIFOBuffer *_fb);
-INLINE bool fifo_isfull_locked(const volatile FIFOBuffer *_fb)
+INLINE bool fifo_isfull_locked(const FIFOBuffer *_fb)
{
bool _result;
cpuflags_t _flags;
return _result;
}
-#endif /* MWARE_FIFOBUF_H */
+
+/*!
+ * 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 / commitdiff