mirror of https://github.com/ArduPilot/ardupilot
23 lines
818 B
C
23 lines
818 B
C
#ifndef __AP_HAL_UTILITY_RINGBUFFER_H__
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#define __AP_HAL_UTILITY_RINGBUFFER_H__
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/*
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common ring buffer handling macros
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These macros assume a ring buffer like this:
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uint8_t *_buf;
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uint16_t _buf_size;
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volatile uint16_t _buf_head;
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volatile uint16_t _buf_tail;
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These should be converted to a class in future
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*/
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#define BUF_AVAILABLE(buf) ((buf##_head > (_tail=buf##_tail))? (buf##_size - buf##_head) + _tail: _tail - buf##_head)
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#define BUF_SPACE(buf) (((_head=buf##_head) > buf##_tail)?(_head - buf##_tail) - 1:((buf##_size - buf##_tail) + _head) - 1)
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#define BUF_EMPTY(buf) (buf##_head == buf##_tail)
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#define BUF_ADVANCETAIL(buf, n) buf##_tail = (buf##_tail + n) % buf##_size
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#define BUF_ADVANCEHEAD(buf, n) buf##_head = (buf##_head + n) % buf##_size
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#endif // __AP_HAL_UTILITY_RINGBUFFER_H__
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