1 /*
   2  * Copyright (c) 2008, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package sun.font;
  27 
  28 import java.io.File;
  29 import java.io.OutputStream;
  30 import java.security.AccessController;
  31 import java.security.PrivilegedAction;
  32 import java.util.HashMap;
  33 import java.util.Map;
  34 import java.util.concurrent.Semaphore;
  35 import java.util.concurrent.TimeUnit;
  36 
  37 import sun.awt.AppContext;
  38 import sun.misc.ThreadGroupUtils;
  39 
  40 public class CreatedFontTracker {
  41 
  42     public static final int MAX_FILE_SIZE = 32 * 1024 * 1024;
  43     public static final int MAX_TOTAL_BYTES = 10 * MAX_FILE_SIZE;
  44 
  45     static CreatedFontTracker tracker;
  46     int numBytes;
  47 
  48     public static synchronized CreatedFontTracker getTracker() {
  49         if (tracker == null) {
  50             tracker = new CreatedFontTracker();
  51         }
  52         return tracker;
  53     }
  54 
  55     private CreatedFontTracker() {
  56         numBytes = 0;
  57     }
  58 
  59     public synchronized int getNumBytes() {
  60         return numBytes;
  61     }
  62 
  63     public synchronized void addBytes(int sz) {
  64         numBytes += sz;
  65     }
  66 
  67     public synchronized void subBytes(int sz) {
  68         numBytes -= sz;
  69     }
  70 
  71     /**
  72      * Returns an AppContext-specific counting semaphore.
  73      */
  74     private static synchronized Semaphore getCS() {
  75         final AppContext appContext = AppContext.getAppContext();
  76         Semaphore cs = (Semaphore) appContext.get(CreatedFontTracker.class);
  77         if (cs == null) {
  78             // Make a semaphore with 5 permits that obeys the first-in first-out
  79             // granting of permits.
  80             cs = new Semaphore(5, true);
  81             appContext.put(CreatedFontTracker.class, cs);
  82         }
  83         return cs;
  84     }
  85 
  86     public boolean acquirePermit() throws InterruptedException {
  87         // This does a timed-out wait.
  88         return getCS().tryAcquire(120, TimeUnit.SECONDS);
  89     }
  90 
  91     public void releasePermit() {
  92         getCS().release();
  93     }
  94 
  95     public void add(File file) {
  96         TempFileDeletionHook.add(file);
  97     }
  98 
  99     public void set(File file, OutputStream os) {
 100         TempFileDeletionHook.set(file, os);
 101     }
 102 
 103     public void remove(File file) {
 104         TempFileDeletionHook.remove(file);
 105     }
 106 
 107     /**
 108      * Helper class for cleanup of temp files created while processing fonts.
 109      * Note that this only applies to createFont() from an InputStream object.
 110      */
 111     private static class TempFileDeletionHook {
 112         private static HashMap<File, OutputStream> files = new HashMap<>();
 113 
 114         private static Thread t = null;
 115         static void init() {
 116             if (t == null) {
 117                 // Add a shutdown hook to remove the temp file.
 118                 AccessController.doPrivileged(
 119                         (PrivilegedAction<Void>) () -> {
 120                             /* The thread must be a member of a thread group
 121                              * which will not get GCed before VM exit.
 122                              * Make its parent the top-level thread group.
 123                              */
 124                             ThreadGroup rootTG = ThreadGroupUtils.getRootThreadGroup();
 125                             t = new Thread(rootTG, TempFileDeletionHook::runHooks);
 126                             t.setContextClassLoader(null);
 127                             Runtime.getRuntime().addShutdownHook(t);
 128                             return null;
 129                         });
 130             }
 131         }
 132 
 133         private TempFileDeletionHook() {}
 134 
 135         static synchronized void add(File file) {
 136             init();
 137             files.put(file, null);
 138         }
 139 
 140         static synchronized void set(File file, OutputStream os) {
 141             files.put(file, os);
 142         }
 143 
 144         static synchronized void remove(File file) {
 145             files.remove(file);
 146         }
 147 
 148         static synchronized void runHooks() {
 149             if (files.isEmpty()) {
 150                 return;
 151             }
 152 
 153             for (Map.Entry<File, OutputStream> entry : files.entrySet()) {
 154                 // Close the associated output stream, and then delete the file.
 155                 try {
 156                     if (entry.getValue() != null) {
 157                         entry.getValue().close();
 158                     }
 159                 } catch (Exception e) {}
 160                 entry.getKey().delete();
 161             }
 162         }
 163     }
 164 }