1 /*
   2  * Copyright (c) 2014, 2015, 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.hotspot;
  24 
  25 import java.io.FileNotFoundException;
  26 import java.io.FileOutputStream;
  27 import java.io.IOException;
  28 import java.io.OutputStream;
  29 import java.io.PrintStream;
  30 import java.lang.management.ManagementFactory;
  31 import java.lang.management.RuntimeMXBean;
  32 
  33 import org.graalvm.compiler.options.OptionValue;
  34 import org.graalvm.compiler.options.UniquePathUtilities;
  35 
  36 import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;
  37 import jdk.vm.ci.hotspot.HotSpotJVMCIRuntimeProvider;
  38 
  39 /**
  40  * An option that encapsulates and configures a print stream.
  41  */
  42 public class PrintStreamOption extends OptionValue<String> {
  43 
  44     public PrintStreamOption() {
  45         super(null);
  46     }
  47 
  48     /**
  49      * The print stream to which output will be written.
  50      *
  51      * Declared {@code volatile} to enable safe use of double-checked locking in
  52      * {@link #getStream()} and {@link #setValue(Object)}.
  53      */
  54     private volatile PrintStream ps;
  55 
  56     /**
  57      * Replaces any instance of %p with an identifying name such as a process ID extracted from
  58      * {@link RuntimeMXBean#getName()} and any instance of %t with the value of
  59      * {@link System#currentTimeMillis()}.
  60      *
  61      * @return the name of the file to log to
  62      */
  63     private String getFilename() {
  64         String name = getValue();
  65         if (name.contains("%t")) {
  66             name = name.replaceAll("%t", String.valueOf(UniquePathUtilities.getGlobalTimeStamp()));
  67         }
  68         if (name.contains("%p")) {
  69             String runtimeName = ManagementFactory.getRuntimeMXBean().getName();
  70             try {
  71                 int index = runtimeName.indexOf('@');
  72                 if (index != -1) {
  73                     long pid = Long.parseLong(runtimeName.substring(0, index));
  74                     runtimeName = Long.toString(pid);
  75                 }
  76                 name = name.replaceAll("%p", runtimeName);
  77             } catch (NumberFormatException e) {
  78 
  79             }
  80         }
  81         return name;
  82     }
  83 
  84     /**
  85      * An output stream that redirects to {@link HotSpotJVMCIRuntimeProvider#getLogStream()}. The
  86      * {@link HotSpotJVMCIRuntimeProvider#getLogStream()} value is only accessed the first time an
  87      * IO operation is performed on the stream. This is required to break a deadlock in early JVMCI
  88      * initialization.
  89      */
  90     static class DelayedOutputStream extends OutputStream {
  91         private volatile OutputStream lazy;
  92 
  93         private OutputStream lazy() {
  94             if (lazy == null) {
  95                 synchronized (this) {
  96                     if (lazy == null) {
  97                         lazy = HotSpotJVMCIRuntime.runtime().getLogStream();
  98                     }
  99                 }
 100             }
 101             return lazy;
 102         }
 103 
 104         @Override
 105         public void write(byte[] b, int off, int len) throws IOException {
 106             lazy().write(b, off, len);
 107         }
 108 
 109         @Override
 110         public void write(int b) throws IOException {
 111             lazy().write(b);
 112         }
 113 
 114         @Override
 115         public void flush() throws IOException {
 116             lazy().flush();
 117         }
 118 
 119         @Override
 120         public void close() throws IOException {
 121             lazy().close();
 122         }
 123     }
 124 
 125     /**
 126      * Gets the print stream configured by this option. If no file is configured, the print stream
 127      * will output to HotSpot's {@link HotSpotJVMCIRuntimeProvider#getLogStream() log} stream.
 128      */
 129     public PrintStream getStream() {
 130         if (ps == null) {
 131             if (getValue() != null) {
 132                 synchronized (this) {
 133                     if (ps == null) {
 134                         try {
 135                             final boolean enableAutoflush = true;
 136                             ps = new PrintStream(new FileOutputStream(getFilename()), enableAutoflush);
 137                             /*
 138                              * Add the JVM and Java arguments to the log file to help identity it.
 139                              */
 140                             String inputArguments = String.join(" ", ManagementFactory.getRuntimeMXBean().getInputArguments());
 141                             ps.println("VM Arguments: " + inputArguments);
 142                             String cmd = System.getProperty("sun.java.command");
 143                             if (cmd != null) {
 144                                 ps.println("sun.java.command=" + cmd);
 145                             }
 146                         } catch (FileNotFoundException e) {
 147                             throw new RuntimeException("couldn't open file: " + getValue(), e);
 148                         }
 149                     }
 150                 }
 151             } else {
 152                 ps = new PrintStream(new DelayedOutputStream());
 153             }
 154         }
 155         return ps;
 156     }
 157 
 158     @Override
 159     public void setValue(Object v) {
 160         if (ps != null) {
 161             synchronized (this) {
 162                 if (ps != null) {
 163                     ps.close();
 164                     ps = null;
 165                 }
 166             }
 167         }
 168         super.setValue(v);
 169     }
 170 }