Reducing the cost of moving bytes through a JVM process: sendfile and FileChannel.transferTo, mmap and MappedByteBuffer, direct versus heap buffers at the syscall boundary, io_uring's submission and completion model and the three routes a JVM can actually reach it by, and proving a copy was eliminated. Use when CPU saturates while a service streams files or proxies bytes, when a loop reads into a ByteBuffer only to write it straight back out, when someone claims java.nio uses io_uring underneath, when a Netty io_uring bootstrap fails at runtime with NoSuchMethodError or ClassNotFoundException, when separating generic and io_uring-specific channel options, or when JFR repo…
