--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/BaseFileManager.java	Wed Jul 05 21:19:32 2017 +0200
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/BaseFileManager.java	Tue Feb 09 14:07:23 2016 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -55,8 +55,6 @@
 
 import com.sun.tools.javac.code.Lint;
 import com.sun.tools.javac.code.Source;
-import com.sun.tools.javac.file.FSInfo;
-import com.sun.tools.javac.file.Locations;
 import com.sun.tools.javac.main.Option;
 import com.sun.tools.javac.main.OptionHelper;
 import com.sun.tools.javac.main.OptionHelper.GrumpyHelper;
@@ -88,6 +86,27 @@
         options = Options.instance(context);
         classLoaderClass = options.get("procloader");
         locations.update(log, Lint.instance(context), FSInfo.instance(context));
+
+        // Setting this option is an indication that close() should defer actually closing
+        // the file manager until after a specified period of inactivity.
+        // This is to accomodate clients which save references to Symbols created for use
+        // within doclets or annotation processors, and which then attempt to use those
+        // references after the tool exits, having closed any internally managed file manager.
+        // Ideally, such clients should run the tool via the javax.tools API, providing their
+        // own file manager, which can be closed by the client when all use of that file
+        // manager is complete.
+        // If the option has a numeric value, it will be interpreted as the duration,
+        // in seconds, of the period of inactivity to wait for, before the file manager
+        // is actually closed.
+        // See also deferredClose().
+        String s = options.get("fileManager.deferClose");
+        if (s != null) {
+            try {
+                deferredCloseTimeout = (int) (Float.parseFloat(s) * 1000);
+            } catch (NumberFormatException e) {
+                deferredCloseTimeout = 60 * 1000;  // default: one minute, in millis
+            }
+        }
     }
 
     protected Locations createLocations() {
@@ -116,6 +135,42 @@
      */
     public boolean autoClose;
 
+    /**
+     * Wait for a period of inactivity before calling close().
+     * The length of the period of inactivity is given by {@code deferredCloseTimeout}
+     */
+    protected void deferredClose() {
+        Thread t = new Thread(getClass().getName() + " DeferredClose") {
+            @Override
+            public void run() {
+                try {
+                    synchronized (BaseFileManager.this) {
+                        long now = System.currentTimeMillis();
+                        while (now < lastUsedTime + deferredCloseTimeout) {
+                            BaseFileManager.this.wait(lastUsedTime + deferredCloseTimeout - now);
+                            now = System.currentTimeMillis();
+                        }
+                        deferredCloseTimeout = 0;
+                        close();
+                    }
+                } catch (InterruptedException e) {
+                } catch (IOException e) {
+                }
+            }
+        };
+        t.setDaemon(true);
+        t.start();
+    }
+
+    synchronized void updateLastUsedTime() {
+        if (deferredCloseTimeout > 0) { // avoid updating the time unnecessarily
+            lastUsedTime = System.currentTimeMillis();
+        }
+    }
+
+    private long lastUsedTime = System.currentTimeMillis();
+    protected long deferredCloseTimeout = 0;
+
     protected Source getSource() {
         String sourceName = options.get(Option.SOURCE);
         Source source = null;

--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/JavacFileManager.java	Wed Jul 05 21:19:32 2017 +0200
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/JavacFileManager.java	Tue Feb 09 14:07:23 2016 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -525,8 +525,16 @@
      */
     @Override @DefinedBy(Api.COMPILER)
     public void close() throws IOException {
-        for (FileSystem fs: fileSystems.values())
+        if (deferredCloseTimeout > 0) {
+            deferredClose();
+            return;
+        }
+
+        for (FileSystem fs: fileSystems.values()) {
             fs.close();
+        }
+        fileSystems.clear();
+        contentCache.clear();
     }
 
     @Override @DefinedBy(Api.COMPILER)

--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/PathFileObject.java	Wed Jul 05 21:19:32 2017 +0200
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/file/PathFileObject.java	Tue Feb 09 14:07:23 2016 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -432,11 +432,13 @@
 
     @Override @DefinedBy(Api.COMPILER)
     public InputStream openInputStream() throws IOException {
+        fileManager.updateLastUsedTime();
         return Files.newInputStream(path);
     }
 
     @Override @DefinedBy(Api.COMPILER)
     public OutputStream openOutputStream() throws IOException {
+        fileManager.updateLastUsedTime();
         fileManager.flushCache(this);
         ensureParentDirectoriesExist();
         return Files.newOutputStream(path);
@@ -471,6 +473,7 @@
 
     @Override @DefinedBy(Api.COMPILER)
     public Writer openWriter() throws IOException {
+        fileManager.updateLastUsedTime();
         fileManager.flushCache(this);
         ensureParentDirectoriesExist();
         return new OutputStreamWriter(Files.newOutputStream(path), fileManager.getEncodingName());

--- a/langtools/test/tools/javac/diags/CheckResourceKeys.java	Wed Jul 05 21:19:32 2017 +0200
+++ b/langtools/test/tools/javac/diags/CheckResourceKeys.java	Tue Feb 09 14:07:23 2016 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -289,6 +289,7 @@
             // -XD option names
             "process.packages",
             "ignore.symbol.file",
+            "fileManager.deferClose",
             // prefix/embedded strings
             "compiler.",
             "compiler.misc.",

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javadoc/8147801/T8147801.java	Tue Feb 09 14:07:23 2016 -0800
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8147801
+ * @summary java.nio.file.ClosedFileSystemException when using Javadoc API's in JDK9
+ * @modules jdk.javadoc/com.sun.tools.javadoc
+ * @library jarsrc
+ * @build lib.* p.*
+ * @run main T8147801
+ */
+
+import java.io.IOException;
+import java.nio.file.ClosedFileSystemException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.jar.JarEntry;
+import java.util.jar.JarOutputStream;
+
+import com.sun.javadoc.ClassDoc;
+import com.sun.javadoc.FieldDoc;
+import com.sun.javadoc.RootDoc;
+
+/*
+ * This test verifies the use of the hidden fileManager.deferClose
+ * option, to work around the limitation that javadoc objects
+ * (like RootDoc and related types) should cannot normally be used
+ * after javadoc exits, closing its file manager (if it opened it.)
+ *
+ * The test runs javadoc on a chain of classes, 1 in source form,
+ * and 2 in a jar file. javadoc/javac will "complete" classes found
+ * in source, but will eagerly "classes" in class form.
+ * The chain is p/Test.java -> lib/Lib1.class -> lib/Lib2.class.
+ * After javadoc exits, the classes are examined, to finally force
+ * the classes to be completed, possibly causing javac to try and access
+ * references into a .jar file system which has now been closed.
+ *
+ * The test runs two test cases -- one without the workaround option,
+ * to test the validity of the test case, and one with the workaround
+ * option, to test that it works as expected.
+ */
+public class T8147801 {
+    public static void main(String... args) throws Exception {
+        new T8147801().run();
+    }
+
+    void run() throws Exception {
+        initJar();
+        test(false);
+        test(true);
+        if (errors > 0) {
+            throw new Exception(errors + " errors occurred");
+        }
+    }
+
+    void test(boolean withOption) {
+        System.err.println("Testing " + (withOption ? "with" : "without") + " option");
+        try {
+            RootDoc root = getRootDoc(withOption);
+            for (ClassDoc cd: root.specifiedClasses()) {
+                dump("", cd);
+            }
+            if (!withOption) {
+                error("expected option did not occur");
+            }
+        } catch (ClosedFileSystemException e) {
+            if (withOption) {
+                error("Unexpected exception: " + e);
+            } else {
+                System.err.println("Exception received as expected: " + e);
+            }
+        }
+        System.err.println();
+    }
+
+    RootDoc getRootDoc(boolean withOption) {
+        List<String> opts = new ArrayList<>();
+        if (withOption)
+            opts.add("-XDfileManager.deferClose=10");
+        opts.add("-doclet");
+        opts.add(getClass().getName());
+        opts.add("-classpath");
+        opts.add(jarPath.toString());
+        opts.add(Paths.get(System.getProperty("test.src"), "p", "Test.java").toString());
+        System.err.println("javadoc opts: " + opts);
+        int rc = com.sun.tools.javadoc.Main.execute(
+                "javadoc",
+                // by specifying our own class loader, we get the same Class instance as this
+                getClass().getClassLoader(),
+                opts.toArray(new String[opts.size()]));
+        if (rc != 0) {
+            error("unexpected exit from javadoc or doclet: " + rc);
+        }
+        return cachedRoot;
+    }
+
+    void dump(String prefix, ClassDoc cd) {
+        System.err.println(prefix + "class: " + cd);
+        for (FieldDoc fd: cd.fields()) {
+            System.err.println(fd);
+            if (fd.type().asClassDoc() != null) {
+                dump(prefix + "  ", fd.type().asClassDoc());
+            }
+        }
+    }
+
+    void initJar() throws IOException {
+        Path testClasses = Paths.get(System.getProperty("test.classes"));
+        jarPath = Paths.get("lib.jar");
+        try (JarOutputStream out = new JarOutputStream(Files.newOutputStream(jarPath))) {
+            String[] classNames = {"Lib1.class", "Lib2.class"};
+            for (String cn : classNames) {
+                out.putNextEntry(new JarEntry("lib/" + cn));
+                Path libClass = testClasses.resolve("jarsrc").resolve("lib").resolve(cn);
+                out.write(Files.readAllBytes(libClass));
+            }
+        }
+    }
+
+    void error(String msg) {
+        System.err.println("Error: " + msg);
+        errors++;
+    }
+
+    Path jarPath;
+    int errors;
+
+    // Bad doclet caches the RootDoc for later use
+
+    static RootDoc cachedRoot;
+
+    public static boolean start(RootDoc root) {
+        cachedRoot = root;
+        return true;
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javadoc/8147801/jarsrc/lib/Lib1.java	Tue Feb 09 14:07:23 2016 -0800
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package lib;
+
+public class Lib1 {
+    public Lib2 lib2;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javadoc/8147801/jarsrc/lib/Lib2.java	Tue Feb 09 14:07:23 2016 -0800
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package lib;
+
+public class Lib2 {
+    int i;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javadoc/8147801/p/Test.java	Tue Feb 09 14:07:23 2016 -0800
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package p;
+
+public class Test {
+    public lib.Lib1 lib1;
+}
+