1 /* 2 * Copyright (c) 2012, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package jdk.vm.ci.meta; 24 25 /** 26 * Manages unique deoptimization reasons. Reasons are embedded in compiled code and can be 27 * invalidated at run time. Subsequent compilations then should not speculate again on such 28 * invalidated reasons to avoid repeated deoptimization. 29 * 30 * All methods of this interface are called by the compiler. There is no need for API to register 31 * failed speculations during deoptimization, since every VM has different needs there. 32 */ 33 public interface SpeculationLog { 34 35 /** 36 * Marker interface for speculation objects that can be added to the speculation log. 37 */ 38 public interface SpeculationReason { 39 } 40 41 /** 42 * Must be called before compilation, i.e., before a compiler calls {@link #maySpeculate}. 43 */ 44 void collectFailedSpeculations(); 45 46 /** 47 * If this method returns true, the compiler is allowed to {@link #speculate} with the given 48 * reason. 49 */ 50 boolean maySpeculate(SpeculationReason reason); 51 52 /** 53 * Registers a speculation that was performed by the compiler. 54 * 55 * @return A compiler constant encapsulating the provided reason. It is usually passed as an 56 * argument to the deoptimization function. 57 */ 58 JavaConstant speculate(SpeculationReason reason); 59 60 /** 61 * Returns if this log has speculations. 62 * 63 * @return true if there are speculations, false otherwise 64 */ 65 boolean hasSpeculations(); 66 }