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In the beginning the indexes end and start are set to 0. The circular buffer write operation writes an element to the end index position and the end index is incremented to the next buffer position. The circular buffer read operation reads an element from the start index position and the start index is incremented to the next buffer position.
The start and end indexes alone are not enough to distinguish between buffer full or empty state while also utilizing all buffer slots,<ref>{{cite web|last1=Chandrasekaran|first1=Siddharth|title=Implementing Circular/Ring Buffer in Embedded C|url=https://embedjournal.com/implementing-circular-buffer-embedded-c/|website=Embed Journal|publisher=EmbedJournal Team|access-date=14 August 2017|archive-url=https://web.archive.org/web/20170211031659/http://embedjournal.com/implementing-circular-buffer-embedded-c/|archive-date=11 February 2017|url-status=live|date=2014-05-16}}</ref> but can be if the buffer only has a maximum in-use size of Length − 1.<ref>[https://www.kernel.org/doc/Documentation/circular-buffers.txt#:~:text=A%20circular%20buffer%20is%20a,next%20item%20in%20the%20buffer Circular buffers] kernel.org</ref> In this case, the buffer is empty if the start and end indexes are equal and full when the in-use size is Length
Another solution is to have another integer count that is incremented at a write operation and decremented at a read operation. Then checking for emptiness means testing count equals 0 and checking for fullness means testing count equals Length.<ref>{{cite web |title=ArrayQueue: An Array-Based Queue |url=http://opendatastructures.org/ods-python/2_3_ArrayQueue_Array_Based_.html |website=Open Data Structures (in pseudocode) |first=Pat |last=Morin|author-link= Pat Morin |access-date=7 November 2015 |archive-url=https://web.archive.org/web/20150831023453/http://opendatastructures.org/ods-python/2_3_ArrayQueue_Array_Based_.html |archive-date=31 August 2015 |url-status=live }}</ref>
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