X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=mware%2Ffifobuf.h;h=cb634ee32ffe14e004c97a6645260380d333ba81;hb=faf2f6bfd5933ff75e6cc01e3d48f9277f731d8f;hp=8da90c20dfa155dbf2af4ea95b175ed41844ab3f;hpb=98987d2acece707588d10148fc04c0a05a99560d;p=bertos.git diff --git a/mware/fifobuf.h b/mware/fifobuf.h old mode 100755 new mode 100644 index 8da90c20..cb634ee3 --- a/mware/fifobuf.h +++ b/mware/fifobuf.h @@ -1,9 +1,34 @@ -/*! +/** * \file * * * \version $Id$ @@ -41,32 +66,12 @@ * \code head == begin && tail == end \endcode */ -/* - * $Log$ - * Revision 1.9 2004/07/20 23:54:27 bernie - * fifo_flush_locked(): New function; - * Revamp documentation. - * - * Revision 1.8 2004/07/20 23:47:39 bernie - * Finally remove redundant protos. - * - * Revision 1.7 2004/07/20 23:46:29 bernie - * Finally remove redundant protos. - * - * Revision 1.6 2004/06/06 17:18:04 bernie - * Remove redundant declaration of fifo_isempty_locked(). - * - * Revision 1.5 2004/06/06 16:50:35 bernie - * Import fixes for race conditions from project_ks. - * - * Revision 1.4 2004/06/06 16:11:17 bernie - * Protect MetroWerks specific pragmas with #ifdef's - */ - #ifndef MWARE_FIFO_H #define MWARE_FIFO_H -#include "cpu.h" +#include +#include +#include typedef struct FIFOBuffer { @@ -77,7 +82,16 @@ typedef struct FIFOBuffer } FIFOBuffer; -/*! +#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 @@ -89,11 +103,12 @@ typedef struct FIFOBuffer */ 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 @@ -108,14 +123,15 @@ INLINE bool fifo_isempty(const FIFOBuffer *fb) */ 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); } -/*! - * 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 @@ -133,10 +149,12 @@ 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 @@ -145,7 +163,7 @@ INLINE void fifo_push(FIFOBuffer *fb, unsigned char c) } -/*! +/** * Pop a character from the fifo buffer. * * \note Calling \c fifo_pop() on an empty buffer is undefined. @@ -160,7 +178,9 @@ INLINE unsigned char fifo_pop(FIFOBuffer *fb) #ifdef __MWERKS__ #pragma interrupt called #endif - if (fb->head == fb->end) + //ASSERT_VALID_FIFO(fb); + + if (UNLIKELY(fb->head == fb->end)) { /* wrap head around */ fb->head = fb->begin; @@ -172,44 +192,46 @@ INLINE unsigned char fifo_pop(FIFOBuffer *fb) } -/*! +/** * Make the fifo empty, discarding all its current contents. */ INLINE void fifo_flush(FIFOBuffer *fb) { + //ASSERT_VALID_FIFO(fb); fb->head = fb->tail; } -#if !defined(__AVR__) +#if CPU_REG_BITS >= CPU_BITS_PER_PTR - /* No tricks needed on 16/32bit CPUs */ -# define fifo_isempty_locked(fb) fifo_isempty((fb)) -# define fifo_push_locked(fb, c) fifo_push((fb), (c)) -# define fifo_flush_locked(fb, c) fifo_flush((fb), (c)) + /* + * 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 /* !__AVR__ */ +#else /* CPU_REG_BITS < CPU_BITS_PER_PTR */ - /*! + /** * Similar to fifo_isempty(), but with stronger guarantees for * concurrent access between user and interrupt code. - * This is actually only needed for 8-bit processors. + * + * \note This is actually only needed for 8-bit processors. * * \sa fifo_isempty() */ INLINE bool fifo_isempty_locked(const FIFOBuffer *fb) { bool result; - cpuflags_t flags; - - DISABLE_IRQSAVE(flags); - result = fifo_isempty(fb); - ENABLE_IRQRESTORE(flags); - + ATOMIC(result = fifo_isempty(fb)); return result; } - /*! + + /** * Similar to fifo_push(), but with stronger guarantees for * concurrent access between user and interrupt code. * @@ -219,13 +241,18 @@ INLINE void fifo_flush(FIFOBuffer *fb) */ INLINE void fifo_push_locked(FIFOBuffer *fb, unsigned char c) { - cpuflags_t flags; - DISABLE_IRQSAVE(flags); - fifo_push(fb, c); - ENABLE_IRQRESTORE(flags); + 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. * @@ -235,36 +262,31 @@ INLINE void fifo_flush(FIFOBuffer *fb) */ INLINE void fifo_flush_locked(FIFOBuffer *fb) { - cpuflags_t flags; - DISABLE_IRQSAVE(flags); - fifo_flush(fb); - ENABLE_IRQRESTORE(flags); + ATOMIC(fifo_flush(fb)); } -#endif /* !__AVR__ */ +#endif /* CPU_REG_BITS < BITS_PER_PTR */ -/*! +/** * 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; + 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; }