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 24 25 package org.graalvm.compiler.core.common.util; 26 27 import org.graalvm.compiler.debug.Assertions; 28 import org.graalvm.compiler.options.Option; 29 import org.graalvm.compiler.options.OptionKey; 30 import org.graalvm.compiler.options.OptionType; 31 import org.graalvm.compiler.options.OptionValues; 32 33 /** 34 * Utility class that allows the compiler to monitor compilations that take a very long time. 35 */ 36 public final class CompilationAlarm implements AutoCloseable { 37 38 public static class Options { 39 // @formatter:off 40 @Option(help = "Time limit in seconds before a compilation expires (0 to disable the limit). " + 41 "The compilation alarm will be implicitly disabled if assertions are enabled.", type = OptionType.Debug) 42 public static final OptionKey<Integer> CompilationExpirationPeriod = new OptionKey<>(300); 43 // @formatter:on 44 } 45 46 private CompilationAlarm(long expiration) { 47 this.expiration = expiration; 48 } 49 50 /** 51 * Thread local storage for the active compilation alarm. 52 */ 53 private static final ThreadLocal<CompilationAlarm> currentAlarm = new ThreadLocal<>(); 54 55 private static final CompilationAlarm NEVER_EXPIRES = new CompilationAlarm(0); 56 57 /** 58 * Gets the current compilation alarm. If there is no current alarm, a non-null value is 59 * returned that will always return {@code false} for {@link #hasExpired()}. 60 */ 61 public static CompilationAlarm current() { 62 CompilationAlarm alarm = currentAlarm.get(); 63 return alarm == null ? NEVER_EXPIRES : alarm; 64 } 65 66 /** 67 * Determines if this alarm has expired. A compilation expires if it takes longer than 68 * {@linkplain CompilationAlarm.Options#CompilationExpirationPeriod}. 69 * 70 * @return {@code true} if the current compilation already takes longer than 71 * {@linkplain CompilationAlarm.Options#CompilationExpirationPeriod}, {@code false} 72 * otherwise 73 */ 74 public boolean hasExpired() { 75 return this != NEVER_EXPIRES && System.currentTimeMillis() > expiration; 76 } 77 78 @Override 79 public void close() { 80 if (this != NEVER_EXPIRES) { 81 currentAlarm.set(null); 82 } 83 } 84 85 /** 86 * The time at which this alarm expires. 87 */ 88 private final long expiration; 89 90 /** 91 * Starts an alarm for setting a time limit on a compilation if there isn't already an active 92 * alarm, if assertions are disabled and 93 * {@link CompilationAlarm.Options#CompilationExpirationPeriod}{@code > 0}. The returned value 94 * can be used in a try-with-resource statement to disable the alarm once the compilation is 95 * finished. 96 * 97 * @return a {@link CompilationAlarm} if there was no current alarm for the calling thread 98 * before this call otherwise {@code null} 99 */ 100 public static CompilationAlarm trackCompilationPeriod(OptionValues options) { 101 int period = Assertions.assertionsEnabled() ? 0 : Options.CompilationExpirationPeriod.getValue(options); 102 if (period > 0) { 103 CompilationAlarm current = currentAlarm.get(); 104 if (current == null) { 105 long expiration = System.currentTimeMillis() + period * 1000; 106 current = new CompilationAlarm(expiration); 107 currentAlarm.set(current); 108 return current; 109 } 110 } 111 return null; 112 } 113 114 }