Squeeze out the last 5%

int i = 0;
for (;;) {
  if (array.length == i) {
    break;
  }
  doSomething(array[i++]);
}

doSomething(array[0]);
doSomething(array[1]);
doSomething(array[2]);
doSomething(array[3]);

public void methodA() {
  ... // Do some work A (3)
  ... // Do some more work B (4)
}

java \
-XX:+PrintCompilation \ (1)
-XX:+UnlockDiagnosticVMOptions \ (2)
-XX:+PrintInlining \ (3)
.... > inline.log

@ 42   io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe::read (191 bytes)   inline (hot) (1)
@ 42   io.netty.channel.nio.AbstractNioMessageChannel$NioMessageUnsafe::read (327 bytes)   hot method too big (2)
  @ 4   io.netty.channel.socket.nio.NioSocketChannel::config (5 bytes)   inline (hot)
    @ 1   io.netty.channel.socket.nio.NioSocketChannel::config (5 bytes)   inline (hot)
  @ 12   io.netty.channel.AbstractChannel::pipeline (5 bytes)   inline (hot)

private final class NioMessageUnsafe extends AbstractNioUnsafe {
  public void read() {
    final SelectionKey key = selectionKey();
    if (!config().isAutoRead()) {
      int interestOps = key.interestOps();
      if ((interestOps & readInterestOp) != 0) {
        // only remove readInterestOp if needed
        key.interestOps(interestOps & ~readInterestOp);
      }
    }
    ... // rest of the method
  }
  ...
}

private final class NioMessageUnsafe extends AbstractNioUnsafe {
  private void removeReadOp() {
    SelectionKey key = selectionKey();
    int interestOps = key.interestOps();
    if ((interestOps & readInterestOp) != 0) {
      // only remove readInterestOp if needed
      key.interestOps(interestOps & ~readInterestOp);
    }
  }

  public void read() {
    if (!config().isAutoRead()) {
      removeReadOp();
    }
    ... // rest of the method
  }
  ...
}

@ 42   io.netty.channel.nio.AbstractNioMessageChannel$NioMessageUnsafe::read (288 bytes)   inline (hot) (1)

public class YourClass {
  @Override
  public void finalize() {
    // cleanup resources and destroy them
  }
}

public class YourClass {
  public void destroy() {
    // cleanup resources and destroy them
  }
}

public class Entry {
  Entry next; (1)
  Entry prev;
  public void methodA() {}
}

public class EntryList {
  Entry head; (2)
  Entry tail;
  public void add(Entry entry) {}
}

public final class FalseSharing implements Runnable {
  private static AtomicLong[] longs = new AtomicLong[NUM_THREADS];
  ....
  public static void runTest() throws InterruptedException {
    Thread[] threads = new Thread[NUM_THREADS];
    for (int i = 0; i < threads.length; i++)
      threads[i] = new Thread(new FalseSharing(i));
    for (Thread t : threads) { t.start(); }
    for (Thread t : threads) { t.join(); }
  }

  public void run() {
    long i = ITERATIONS + 1;
    while (0 != --i) { longs[arrayIndex].set(i); }
  }
}

public final class FalseSharing implements Runnable {
  private static AtomicLong[] longs = new AtomicLong[NUM_THREADS];
  static { 
    for (int i = 0; i < longs.length; i++) {
      longs[i] = new AtomicLong();
    }
  }
  ...
}

public final class FalseSharing implements Runnable {
  private static PaddedAtomicLong[] longs = new PaddedAtomicLong[NUM_THREADS];
  static { 
    for (int i = 0; i < longs.length; i++) {
      longs[i] = new PaddedAtomicLong();
    }
  }
  ...
  public static long sumPaddingToPreventOptimisation(final int index) {
    PaddedAtomicLong v = longs[index];
    return v.p1 + v.p2 + v.p3 + v.p4 + v.p5 + v.p6;
  }

  public static class PaddedAtomicLong extends AtomicLong {
    public volatile long p1, p2, p3, p4, p5, p6 = 7L;
  }
}

public static Unsafe getUnsafe() {
  Class cc = sun.reflect.Reflection.getCallerClass(2);
  if (cc.getClassLoader() != null)
    throw new SecurityException("Unsafe");
  return theUnsafe;
}

private final Object[] array = new Object[128];

private int nextIdx(int index) {
  return (index + 1) % array.length;
}

private final Object[] array = new Object[128];
private final int mask = array.length - 1;

private int nextIdx(int index) {
  return (index + 1) & mask;
}