X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=mware%2Ffifobuf.h;h=1e85558281fe63357fb6f05d290fbeec4b222f00;hb=HEAD;hp=12de29495cf64fc9bbafc8eb0ba14cfeb366c664;hpb=22240d0455c6bd837fe928b29068e795be3febae;p=bertos.git diff --git a/mware/fifobuf.h b/mware/fifobuf.h deleted file mode 100755 index 12de2949..00000000 --- a/mware/fifobuf.h +++ /dev/null @@ -1,341 +0,0 @@ -/*! - * \file - * - * - * \version $Id$ - * - * \author Bernardo Innocenti - * - * \brief General pourpose FIFO buffer implemented with a ring buffer - * - * \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 - * - * +-----------------------------------+ - * | empty | valid data | empty | - * +-----------------------------------+ - * ^ ^ ^ ^ - * begin head tail end - * - * \endcode - * - * The buffer is EMPTY when \c head and \c tail point to the same location: - * \code head == tail \endcode - * - * The buffer is FULL when \c tail points to the location immediately - * after \c head: - * \code tail == head - 1 \endcode - * - * 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 1.12 2004/08/02 20:20:29 aleph - * Merge from project_ks - * - * Revision 1.11 2004/07/30 14:15:53 rasky - * Nuovo supporto unificato per detect della CPU - * - * Revision 1.10 2004/07/29 22:57:09 bernie - * Doxygen fix. - * - * 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" - -typedef struct FIFOBuffer -{ - unsigned char * volatile head; - unsigned char * volatile tail; - unsigned char *begin; - unsigned char *end; -} FIFOBuffer; - - -/*! - * 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 - * (which the AVR and other 8-bit processors can't do). - * - * \sa fifo_isempty_locked - */ -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); -} - - -/*! - * 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, 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 - /* 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) -{ -#ifdef __MWERKS__ -#pragma interrupt called -#endif - 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; -} - - -#if !CPU_AVR - - /* 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) fifo_flush((fb)) - -#else /* !CPU_AVR */ - - /*! - * 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; - cpuflags_t flags; - - DISABLE_IRQSAVE(flags); - result = fifo_isempty(fb); - ENABLE_IRQRESTORE(flags); - - 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) - { - cpuflags_t flags; - DISABLE_IRQSAVE(flags); - fifo_push(fb, c); - ENABLE_IRQRESTORE(flags); - } - - /*! - * 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) - { - cpuflags_t flags; - DISABLE_IRQSAVE(flags); - fifo_flush(fb); - ENABLE_IRQRESTORE(flags); - } - -#endif /* !CPU_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; -} - - -/*! - * 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 */ -