1 /* 2 * Copyright (c) 2016, 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 org.graalvm.compiler.core.common.util; 24 25 import org.graalvm.compiler.options.Option; 26 import org.graalvm.compiler.options.OptionType; 27 import org.graalvm.compiler.options.OptionValue; 28 29 /** 30 * Utility class that allows the compiler to monitor compilations that take a very long time. 31 */ 32 public final class CompilationAlarm implements AutoCloseable { 33 34 public static class Options { 35 // @formatter:off 36 @Option(help = "Time limit in seconds before a compilation expires (0 to disable the limit).", type = OptionType.Debug) 37 public static final OptionValue<Integer> CompilationExpirationPeriod = new OptionValue<>(300); 38 // @formatter:on 39 } 40 41 private CompilationAlarm() { 42 } 43 44 private static boolean enabled() { 45 return Options.CompilationExpirationPeriod.getValue() > 0; 46 } 47 48 /** 49 * Thread local storage for compilation start timestamps. Everytime a compiler thread calls 50 * {@link #trackCompilationPeriod()} it will save the start timestamp of the compilation. 51 */ 52 private static final ThreadLocal<Long> compilationStartedTimeStamps = new ThreadLocal<>(); 53 54 private static boolean compilationStarted() { 55 if (enabled()) { 56 Long start = compilationStartedTimeStamps.get(); 57 if (start == null) { 58 compilationStartedTimeStamps.set(System.currentTimeMillis()); 59 return true; 60 } 61 } 62 return false; 63 } 64 65 private static void compilationFinished() { 66 if (enabled()) { 67 assert compilationStartedTimeStamps.get() != null; 68 compilationStartedTimeStamps.set(null); 69 } 70 } 71 72 /** 73 * Determines if the current compilation is expired. A compilation expires if it takes longer 74 * than {@linkplain CompilationAlarm.Options#CompilationExpirationPeriod}. 75 * 76 * @return {@code true} if the current compilation already takes longer than 77 * {@linkplain CompilationAlarm.Options#CompilationExpirationPeriod}, {@code false} 78 * otherwise 79 */ 80 public static boolean hasExpired() { 81 if (enabled()) { 82 Long start = compilationStartedTimeStamps.get(); 83 if (start != null) { 84 long time = System.currentTimeMillis(); 85 assert time >= start; 86 return time - start > Options.CompilationExpirationPeriod.getValue() * 1000; 87 } 88 } 89 return false; 90 } 91 92 @Override 93 public void close() { 94 compilationFinished(); 95 } 96 97 private static final CompilationAlarm INSTANCE = enabled() ? new CompilationAlarm() : null; 98 99 /** 100 * Gets an object that can be used in a try-with-resource statement to set an time limit based 101 * alarm for a compilation. 102 * 103 * @return a {@link CompilationAlarm} instance if there is no current alarm for the calling 104 * thread otherwise {@code null} 105 */ 106 public static CompilationAlarm trackCompilationPeriod() { 107 if (compilationStarted()) { 108 return INSTANCE; 109 } 110 return null; 111 } 112 113 }