forked from Imagelibrary/rtems
64 lines
1.7 KiB
C
64 lines
1.7 KiB
C
/**
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* @file
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*
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* @brief Simple Ring Buffer Functionality
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*
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* This file provides simple ring buffer functionality.
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*/
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#ifndef _RTEMS_RINGBUF_H
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#define _RTEMS_RINGBUF_H
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#include <rtems.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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uint8_t buffer[RINGBUF_QUEUE_LENGTH];
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volatile int head;
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volatile int tail;
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rtems_interrupt_lock lock;
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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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rtems_interrupt_lock_initialize(&(_buffer)->lock, "ring buffer"); \
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} while ( 0 )
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#define Ring_buffer_Destory( _buffer ) \
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do { \
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rtems_interrupt_lock_destroy(&(_buffer)->lock); \
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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_interrupt_lock_context lock_context; \
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\
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rtems_interrupt_lock_acquire( &(_buffer)->lock, &lock_context ); \
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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_lock_release( &(_buffer)->lock, &lock_context ); \
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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_interrupt_lock_context lock_context; \
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\
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rtems_interrupt_lock_acquire( &(_buffer)->lock, &lock_context ); \
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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_lock_release( &(_buffer)->lock, &lock_context ); \
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} while ( 0 )
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#endif
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