1 /* 2 * Copyright 2009 Sun Microsystems, Inc. All Rights Reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 */ 23 24 /** 25 * @test 26 * @bug 6880034 27 * @summary SIGBUS during deoptimisation at a safepoint on 64bit-SPARC 28 * 29 * @run main/othervm -Xcomp -Xbatch -XX:CompileCommand=compileonly,Test6880034,deopt_compiledframe_at_safepoint -XX:+PrintCompilation Test6880034 30 */ 31 32 33 34 // This test provokes a deoptimisation at a safepoint. 35 // 36 // It achieves this by compiling the method 'deopt_compiledframe_at_safepoint' 37 // before its first usage at a point in time when a call to the virtual method 38 // A::doSomething() from within 'deopt_compiledframe_at_safepoint' can be 39 // optimised to a static call because class A has no descendants. 40 // 41 // Later, when deopt_compiledframe_at_safepoint() is running, class B which 42 // extends A and overrides the virtual method "doSomething()", is loaded 43 // asynchronously in another thread. This makes the compiled code of 44 // 'deopt_compiledframe_at_safepoint' invalid and triggers a deoptimisation of 45 // the frame where 'deopt_compiledframe_at_safepoint' is running in a 46 // loop. 47 // 48 // The deoptimisation leads to a SIGBUS on 64-bit server VMs on SPARC and to 49 // an incorrect result on 32-bit server VMs on SPARC due to a regression 50 // introduced by the change: "6420645: Create a vm that uses compressed oops 51 // for up to 32gb heapsizes" 52 // (http://hg.openjdk.java.net/jdk7/jdk7/hotspot/rev/ba764ed4b6f2). Further 53 // investigation showed that change 6420645 is not really the root cause of 54 // this error but only reveals a problem with the float register encodings in 55 // sparc.ad which was hidden until now. 56 // 57 // Notice that for this test to fail in jtreg it is crucial that 58 // deopt_compiledframe_at_safepoint() runs in the main thread. Otherwise a 59 // crash in deopt_compiledframe_at_safepoint() will not be detected as a test 60 // failure by jtreg. 61 // 62 // Author: Volker H. Simonis 63 64 class A { 65 public int doSomething() { 66 return 0; 67 } 68 } 69 70 class B extends A { 71 public B() {} 72 // override 'A::doSomething()' 73 public int doSomething() { 74 return 1; 75 } 76 } 77 78 class G { 79 public static volatile A a = new A(); 80 81 // Change 'a' to point to a 'B' object 82 public static void setAtoB() { 83 try { 84 a = (A) ClassLoader. 85 getSystemClassLoader(). 86 loadClass("B"). 87 getConstructor(new Class[] {}). 88 newInstance(new Object[] {}); 89 } 90 catch (Exception e) { 91 System.out.println(e); 92 } 93 } 94 } 95 96 public class Test6880034 { 97 98 public static volatile boolean is_in_loop = false; 99 public static volatile boolean stop_while_loop = false; 100 101 public static double deopt_compiledframe_at_safepoint() { 102 // This will be an optimised static call to A::doSomething() until we load "B" 103 int i = G.a.doSomething(); 104 105 // Need more than 16 'double' locals in this frame 106 double local1 = 1; 107 double local2 = 2; 108 double local3 = 3; 109 double local4 = 4; 110 double local5 = 5; 111 double local6 = 6; 112 double local7 = 7; 113 double local8 = 8; 114 115 long k = 0; 116 // Once we load "B", this method will be made 'not entrant' and deoptimised 117 // at the safepoint which is at the end of this loop. 118 while (!stop_while_loop) { 119 if (k == 1) local1 += i; 120 if (k == 2) local2 += i; 121 if (k == 3) local3 += i; 122 if (k == 4) local4 += i; 123 if (k == 5) local5 += i; 124 if (k == 6) local6 += i; 125 if (k == 7) local7 += i; 126 if (k == 8) local8 += i; 127 128 // Tell the world that we're now running wild in the loop 129 if (k++ == 20000) is_in_loop = true; 130 } 131 132 return 133 local1 + local2 + local3 + local4 + 134 local5 + local6 + local7 + local8 + i; 135 } 136 137 public static void main(String[] args) { 138 139 // Just to resolve G before we compile deopt_compiledframe_at_safepoint() 140 G g = new G(); 141 142 // Asynchronous thread which will eventually invalidate the code for 143 // deopt_compiledframe_at_safepoint() and therefore triggering a 144 // deoptimisation of that method. 145 new Thread() { 146 public void run() { 147 while (!is_in_loop) { 148 // Wait until the loop is running 149 } 150 // Load class 'B' asynchronously.. 151 G.setAtoB(); 152 // ..and stop the loop 153 stop_while_loop = true; 154 } 155 }.start(); 156 157 // Run the loop in deopt_compiledframe_at_safepoint() 158 double retVal = deopt_compiledframe_at_safepoint(); 159 160 System.out.println(retVal == 36 ? "OK" : "ERROR : " + retVal); 161 if (retVal != 36) throw new RuntimeException(); 162 } 163 }