17 warnings revealed by "-Wall -pedantic -Wextra"

[Hermann-SW]

Exactly the ringbuffer implementation I searched for, especially the pthread buffer_test demo!

$ gcc -O6 -Wall -pedantic -Wextra ringbuffer.c buffer_test.c -o buffer_test -lpthread 2>&1 | grep warning | wc --lines
17
$

Fixed in my fork:
Hermann-SW@945a8de