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_RINGBUF Struct Reference
[USART Device DriverUSART Device Driver]

#include <dev/usart.h>


Detailed Description

Character device ring buffer structure.


Data Fields

u_charrbf_head
 Buffer head pointer.

u_charrbf_tail
 Buffer tail pointer.

u_charrbf_start
 First buffer address.

u_charrbf_last
 Last buffer address.

size_t rbf_siz
 Total buffer size.

size_t rbf_cnt
 Number of bytes in the buffer.

size_t rbf_lwm
 Buffer low watermark.

size_t rbf_hwm
 Buffer high watermark.

HANDLE rbf_que
 Queue of waiting threads.


Field Documentation

size_t _RINGBUF::rbf_hwm
 

Buffer high watermark.

If the number of bytes in the buffer reaches this value, then buffer input is disabled.

size_t _RINGBUF::rbf_lwm
 

Buffer low watermark.

If the number of bytes in the buffer reaches this value, then the previously disabled buffer input is enabled again.

HANDLE _RINGBUF::rbf_que
 

Queue of waiting threads.

Consuming threads are added to this queue when the buffer is empty. Producing threads are added to this queue when the buffer is full.

size_t _RINGBUF::rbf_siz
 

Total buffer size.

Zero, if no buffer available.


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