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https://gitlab.rtems.org/rtems/rtos/rtems.git
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54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
/*
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* ringbuf.h
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*
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* This file provides simple ring buffer functionality.
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*
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* $Id$
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*/
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#ifndef __RINGBUF_H__
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#define __RINGBUF_H__
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#ifndef RINGBUF_QUEUE_LENGTH
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#define RINGBUF_QUEUE_LENGTH 128
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#endif
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typedef struct {
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char buffer[RINGBUF_QUEUE_LENGTH];
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volatile int head;
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volatile int tail;
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} Ring_buffer_t;
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#define Ring_buffer_Initialize( _buffer ) \
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do { \
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(_buffer)->head = (_buffer)->tail = 0; \
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} while ( 0 )
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#define Ring_buffer_Is_empty( _buffer ) \
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( (_buffer)->head == (_buffer)->tail )
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#define Ring_buffer_Is_full( _buffer ) \
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( (_buffer)->head == ((_buffer)->tail + 1) % RINGBUF_QUEUE_LENGTH )
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#define Ring_buffer_Add_character( _buffer, _ch ) \
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do { \
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rtems_unsigned32 isrlevel; \
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\
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rtems_interrupt_disable( isrlevel ); \
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(_buffer)->tail = ((_buffer)->tail+1) % RINGBUF_QUEUE_LENGTH; \
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(_buffer)->buffer[ (_buffer)->tail ] = (_ch); \
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rtems_interrupt_enable( isrlevel ); \
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} while ( 0 )
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#define Ring_buffer_Remove_character( _buffer, _ch ) \
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do { \
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rtems_unsigned32 isrlevel; \
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\
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rtems_interrupt_disable( isrlevel ); \
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(_buffer)->head = ((_buffer)->head+1) % RINGBUF_QUEUE_LENGTH; \
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(_ch) = (_buffer)->buffer[ (_buffer)->head ]; \
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rtems_interrupt_enable( isrlevel ); \
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} while ( 0 )
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#endif
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