--- /dev/null Mon Oct 5 14:20:54 2009 +++ new/test/compiler/6880034/Test6880034.java Mon Oct 5 14:20:54 2009 @@ -0,0 +1,163 @@ +/* + * Copyright 2009 SAP AG. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + */ + +/** + * @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(); + } +}