102 lines
2.7 KiB
C
102 lines
2.7 KiB
C
#ifndef RINGBUFFER_H_
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#define RINGBUFFER_H_
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#include <stdint.h>
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#ifdef _MSC_VER
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#define inline __inline
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#endif
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/*
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A thread-safe ring buffer, which uses an pre-declared array as buffer.
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But you have to declare a buffer with one more item than you really need.
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For instance, if you need a ring buffer for 10 items, the array must be declared for 11 items.
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*/
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typedef struct {
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uint32_t * reader;
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uint32_t * writer;
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uint32_t * start;
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uint32_t * end;
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} ringbuffer_t;
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/* Use Array as RingBuffer */
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static inline void RingBuffer_Init(ringbuffer_t * const ring_buffer, uint32_t * const array, uint32_t size)
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{
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ring_buffer->start = ring_buffer->reader = ring_buffer->writer = &array[0];
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ring_buffer->end = &array[0] + size - 1;
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}
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static inline uint32_t * RingBuffer_NextAddress(ringbuffer_t * const ring_buffer, uint32_t * const pointer)
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{
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if (pointer == ring_buffer->end)
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return ring_buffer->start;
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else
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return pointer + 1;
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}
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static inline uint8_t RingBuffer_IsFull(ringbuffer_t * const ring_buffer)
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{
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if (RingBuffer_NextAddress(ring_buffer, ring_buffer->writer) == ring_buffer->reader)
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return 1;
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return 0;
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}
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static inline uint8_t RingBuffer_IsEmpty(ringbuffer_t * const ring_buffer)
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{
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if (ring_buffer->writer == ring_buffer->reader)
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return 1;
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return 0;
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}
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static inline uint8_t RingBuffer_IsFilled(ringbuffer_t * const ring_buffer)
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{
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return !RingBuffer_IsEmpty(ring_buffer);
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}
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static inline void RingBuffer_Write(ringbuffer_t * const ring_buffer, uint32_t element)
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{
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if (!RingBuffer_IsFull(ring_buffer))
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{
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*(ring_buffer->writer) = element;
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ring_buffer->writer = RingBuffer_NextAddress(ring_buffer, ring_buffer->writer);
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}
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}
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static inline uint32_t RingBuffer_Read(ringbuffer_t * const ring_buffer)
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{
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uint32_t element = 0;
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if (!RingBuffer_IsEmpty(ring_buffer))
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{
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element = *(ring_buffer->reader);
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ring_buffer->reader = RingBuffer_NextAddress(ring_buffer, ring_buffer->reader);
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}
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return element;
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}
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#define Concat2(a, b) a ## b
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#define Concat(a, b) Concat2(a, b)
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#define UniqueBuffer(name) Concat(name, Concat(_buffer, __LINE__))
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/*
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Macro for the creation of a ring buffer.
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*/
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#define RingBuffer_Create(name, size) \
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uint32_t UniqueBuffer(name)[size]; \
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ringbuffer_t name; \
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RingBuffer_Init(&name, UniqueBuffer(name), size) \
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#define RingBuffer(name, size) \
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uint32_t UniqueBuffer(name)[size]; \
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ringbuffer_t name = { \
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.reader = &UniqueBuffer(name)[0], \
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.writer = &UniqueBuffer(name)[0], \
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.start = &UniqueBuffer(name)[0], \
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.end = &UniqueBuffer(name)[0] + sizeof(UniqueBuffer(name)) / sizeof(UniqueBuffer(name)[0]) \
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}
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#endif
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