prefetch instructions in Hotspot

[Mahmood Naderan]

Right... got it.
Since I am more familiar with C++ than Java, just want to know if I have to recompile/rebuild or update the jdk since I have modified Unsafe.java. Here is my simple code which fails

$ cat Arr.java
public class Arr
{
  public static void main(String[] args)
  {
    int [] a = new int[3];
    a[0] = 10; a[1] = 20; a[2] = 30;
    for (int i = 0; i < 3; i++)
    {
      sun.misc.Unsafe.prefetchRead(a[i]);
      System.out.println(a[i]);
    }
  }
}



$ javac Arr.java
Arr.java:11: warning: sun.misc.Unsafe is internal proprietary API and may be removed in a future release
      sun.misc.Unsafe.prefetchRead(a[i]);
              ^
Arr.java:11: cannot find symbol
symbol  : method prefetchRead(int)
location: class sun.misc.Unsafe
      sun.misc.Unsafe.prefetchRead(a[i]);
                     ^
1 error
1 warning



What did I miss?

 
Regards,
Mahmood


On Wednesday, April 2, 2014 8:54 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
 
>You need to download Hotspot JVM sources too that is where library_call.cpp.
>
>Vladimir