IIUC, os.urandom(16) reads the urandom pool using getrandom() without flags. It will only block, if at all, during a short period after boot until the urandom p

IIUC, os.urandom(16) reads the urandom pool using getrandom() without flags. It will only block, if at all, during a short period after boot until the urandom pool is initialized. Thereafter reading from the urandom pool will never block as there's no way to drain it.