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 /**

  * @test

  * @bug 6880034

  * @summary SIGBUS during deoptimisation at a safepoint on 64bit-SPARC

  *

  * @run main/othervm -Xcomp -Xbatch -XX:CompileCommand=compileonly,Test6880034,deopt_compiledframe_at_safepoint -XX:+PrintCompilation Test6880034

  */

 // This test provokes a deoptimisation at a safepoint.

 //

 // It achieves this by compiling the method 'deopt_compiledframe_at_safepoint'

 // before its first usage at a point in time when a call to the virtual method

 // A::doSomething() from within 'deopt_compiledframe_at_safepoint' can be

 // optimised to a static call because class A has no descendants.

 //

 // Later, when deopt_compiledframe_at_safepoint() is running, class B which

 // extends A and overrides the virtual method "doSomething()", is loaded

 // asynchronously in another thread.  This makes the compiled code of

 // 'deopt_compiledframe_at_safepoint' invalid and triggers a deoptimisation of

 // the frame where 'deopt_compiledframe_at_safepoint' is running in a

 // loop.

 //

 // The deoptimisation leads to a SIGBUS on 64-bit server VMs on SPARC and to

 // an incorrect result on 32-bit server VMs on SPARC due to a regression

 // introduced by the change: "6420645: Create a vm that uses compressed oops

 // for up to 32gb heapsizes"

 // (http://hg.openjdk.java.net/jdk7/jdk7/hotspot/rev/ba764ed4b6f2).  Further

 // investigation showed that change 6420645 is not really the root cause of

 // this error but only reveals a problem with the float register encodings in

 // sparc.ad which was hidden until now.

 //

 // Notice that for this test to fail in jtreg it is crucial that

 // deopt_compiledframe_at_safepoint() runs in the main thread. Otherwise a

 // crash in deopt_compiledframe_at_safepoint() will not be detected as a test

 // failure by jtreg.

 //

 // Author: Volker H. Simonis

 class A {

   public int doSomething() {

     return 0;

   }

 }

 class B extends A {

   public B() {}

   // override 'A::doSomething()'

   public int doSomething() {

     return 1;

   }

 }

 class G {

   public static volatile A a = new A();

   // Change 'a' to point to a 'B' object

   public static void setAtoB() {

     try {

       a =  (A) ClassLoader.

         getSystemClassLoader().

         loadClass("B").

         getConstructor(new Class[] {}).

         newInstance(new Object[] {});

     }

     catch (Exception e) {

       System.out.println(e);

     }

   }

 }

 public class Test6880034 {

   public static volatile boolean is_in_loop = false;

   public static volatile boolean stop_while_loop = false;

   public static double deopt_compiledframe_at_safepoint() {

     // This will be an optimised static call to A::doSomething() until we load "B"

     int i = G.a.doSomething();

     // Need more than 16 'double' locals in this frame

     double local1 = 1;

     double local2 = 2;

     double local3 = 3;

     double local4 = 4;

     double local5 = 5;

     double local6 = 6;

     double local7 = 7;

     double local8 = 8;

     long k = 0;

     // Once we load "B", this method will be made 'not entrant' and deoptimised

     // at the safepoint which is at the end of this loop.

     while (!stop_while_loop) {

       if (k ==  1) local1 += i;

       if (k ==  2) local2 += i;

       if (k ==  3) local3 += i;

       if (k ==  4) local4 += i;

       if (k ==  5) local5 += i;

       if (k ==  6) local6 += i;

       if (k ==  7) local7 += i;

       if (k ==  8) local8 += i;

       // Tell the world that we're now running wild in the loop

       if (k++ == 20000) is_in_loop = true;

     }

     return

       local1 + local2 + local3 + local4 +

       local5 + local6 + local7 + local8 + i;

   }

   public static void main(String[] args) {

     // Just to resolve G before we compile deopt_compiledframe_at_safepoint()

     G g = new G();

     // Asynchronous thread which will eventually invalidate the code for

     // deopt_compiledframe_at_safepoint() and therefore triggering a

     // deoptimisation of that method.

     new Thread() {

       public void run() {

         while (!is_in_loop) {

           // Wait until the loop is running

         }

         // Load class 'B' asynchronously..

         G.setAtoB();

         // ..and stop the loop

         stop_while_loop = true;

       }

     }.start();

     // Run the loop in deopt_compiledframe_at_safepoint()

     double retVal = deopt_compiledframe_at_safepoint();

     System.out.println(retVal == 36 ? "OK" : "ERROR : " + retVal);

     if (retVal != 36) throw new RuntimeException();

   }

 }