8001038: Resourcefully handle resources

Reviewed-by: prr, bae

jdk/src/share/classes/java/awt/Font.java

@@ -873,6 +873,33 @@ public class Font implements java.io.Serializable
     public static Font createFont(int fontFormat, InputStream fontStream)
         throws java.awt.FontFormatException, java.io.IOException {
 
+        if (hasTempPermission()) {
+            return createFont0(fontFormat, fontStream, null);
+        }
+
+        // Otherwise, be extra conscious of pending temp file creation and
+        // resourcefully handle the temp file resources, among other things.
+        CreatedFontTracker tracker = CreatedFontTracker.getTracker();
+        boolean acquired = false;
+        try {
+            acquired = tracker.acquirePermit();
+            if (!acquired) {
+                throw new IOException("Timed out waiting for resources.");
+            }
+            return createFont0(fontFormat, fontStream, tracker);
+        } catch (InterruptedException e) {
+            throw new IOException("Problem reading font data.");
+        } finally {
+            if (acquired) {
+                tracker.releasePermit();
+            }
+        }
+    }
+
+    private static Font createFont0(int fontFormat, InputStream fontStream,
+                                    CreatedFontTracker tracker)
+        throws java.awt.FontFormatException, java.io.IOException {
+
         if (fontFormat != Font.TRUETYPE_FONT &&
             fontFormat != Font.TYPE1_FONT) {
             throw new IllegalArgumentException ("font format not recognized");
@@ -886,9 +913,11 @@ public class Font implements java.io.Serializable
                     }
                 }
             );
+            if (tracker != null) {
+                tracker.add(tFile);
+            }
 
             int totalSize = 0;
-            CreatedFontTracker tracker = null;
             try {
                 final OutputStream outStream =
                     AccessController.doPrivileged(
@@ -898,8 +927,8 @@ public class Font implements java.io.Serializable
                             }
                         }
                     );
-                if (!hasTempPermission()) {
-                    tracker = CreatedFontTracker.getTracker();
+                if (tracker != null) {
+                    tracker.set(tFile, outStream);
                 }
                 try {
                     byte[] buf = new byte[8192];
@@ -940,6 +969,9 @@ public class Font implements java.io.Serializable
                 Font font = new Font(tFile, fontFormat, true, tracker);
                 return font;
             } finally {
+                if (tracker != null) {
+                    tracker.remove(tFile);
+                }
                 if (!copiedFontData) {
                     if (tracker != null) {
                         tracker.subBytes(totalSize);

jdk/src/share/classes/sun/font/CreatedFontTracker.java

@@ -25,13 +25,22 @@
 
 package sun.font;
 
+import java.io.File;
+import java.io.OutputStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+
+import sun.awt.AppContext;
+
 public class CreatedFontTracker {
 
     public static final int MAX_FILE_SIZE = 32 * 1024 * 1024;
     public static final int MAX_TOTAL_BYTES = 10 * MAX_FILE_SIZE;
 
-    static int numBytes;
     static CreatedFontTracker tracker;
+    int numBytes;
 
     public static synchronized CreatedFontTracker getTracker() {
         if (tracker == null) {
@@ -40,6 +49,10 @@ public class CreatedFontTracker {
         return tracker;
     }
 
+    private CreatedFontTracker() {
+        numBytes = 0;
+    }
+
     public synchronized int getNumBytes() {
         return numBytes;
     }
@@ -51,4 +64,108 @@ public class CreatedFontTracker {
     public synchronized void subBytes(int sz) {
         numBytes -= sz;
     }
+
+    /**
+     * Returns an AppContext-specific counting semaphore.
+     */
+    private static synchronized Semaphore getCS() {
+        final AppContext appContext = AppContext.getAppContext();
+        Semaphore cs = (Semaphore) appContext.get(CreatedFontTracker.class);
+        if (cs == null) {
+            // Make a semaphore with 5 permits that obeys the first-in first-out
+            // granting of permits.
+            cs = new Semaphore(5, true);
+            appContext.put(CreatedFontTracker.class, cs);
+        }
+        return cs;
+    }
+
+    public boolean acquirePermit() throws InterruptedException {
+        // This does a timed-out wait.
+        return getCS().tryAcquire(120, TimeUnit.SECONDS);
+    }
+
+    public void releasePermit() {
+        getCS().release();
+    }
+
+    public void add(File file) {
+        TempFileDeletionHook.add(file);
+    }
+
+    public void set(File file, OutputStream os) {
+        TempFileDeletionHook.set(file, os);
+    }
+
+    public void remove(File file) {
+        TempFileDeletionHook.remove(file);
+    }
+
+    /**
+     * Helper class for cleanup of temp files created while processing fonts.
+     * Note that this only applies to createFont() from an InputStream object.
+     */
+    private static class TempFileDeletionHook {
+        private static HashMap<File, OutputStream> files = new HashMap<>();
+
+        private static Thread t = null;
+        static void init() {
+            if (t == null) {
+                // Add a shutdown hook to remove the temp file.
+                java.security.AccessController.doPrivileged(
+                   new java.security.PrivilegedAction() {
+                      public Object run() {
+                          /* The thread must be a member of a thread group
+                           * which will not get GCed before VM exit.
+                           * Make its parent the top-level thread group.
+                           */
+                          ThreadGroup tg =
+                              Thread.currentThread().getThreadGroup();
+                          for (ThreadGroup tgn = tg;
+                               tgn != null;
+                               tg = tgn, tgn = tg.getParent());
+                          t = new Thread(tg, new Runnable() {
+                              public void run() {
+                                  runHooks();
+                              }
+                          });
+                          t.setContextClassLoader(null);
+                          Runtime.getRuntime().addShutdownHook(t);
+                          return null;
+                      }
+                   });
+            }
+        }
+
+        private TempFileDeletionHook() {}
+
+        static synchronized void add(File file) {
+            init();
+            files.put(file, null);
+        }
+
+        static synchronized void set(File file, OutputStream os) {
+            files.put(file, os);
+        }
+
+        static synchronized void remove(File file) {
+            files.remove(file);
+        }
+
+        static synchronized void runHooks() {
+            if (files.isEmpty()) {
+                return;
+            }
+
+            for (Map.Entry<File, OutputStream> entry : files.entrySet()) {
+                // Close the associated output stream, and then delete the file.
+                try {
+                    if (entry.getValue() != null) {
+                        entry.getValue().close();
+                    }
+                } catch (Exception e) {}
+                entry.getKey().delete();
+            }
+        }
+    }
 }