# HG changeset patch
# User martin
# Date 1543444108 28800
#      Wed Nov 28 14:28:28 2018 -0800
# Node ID 396dfb0e8ba53a2c187c0433275c9af0949b8f1c
# Parent  9cfa2e273b7769f0adb7bcea54153c45757b403b
8213406: (fs) More than one instance of built-in FileSystem observed in heap
Reviewed-by: alanb, cushon, weijun

diff --git a/src/java.base/aix/classes/sun/nio/fs/AixFileSystemProvider.java b/src/java.base/aix/classes/sun/nio/fs/AixFileSystemProvider.java
--- a/src/java.base/aix/classes/sun/nio/fs/AixFileSystemProvider.java
+++ b/src/java.base/aix/classes/sun/nio/fs/AixFileSystemProvider.java
@@ -32,7 +32,7 @@
  * AIX implementation of FileSystemProvider
  */
 
-public class AixFileSystemProvider extends UnixFileSystemProvider {
+class AixFileSystemProvider extends UnixFileSystemProvider {
     public AixFileSystemProvider() {
         super();
     }
diff --git a/src/java.base/aix/classes/sun/nio/fs/DefaultFileSystemProvider.java b/src/java.base/aix/classes/sun/nio/fs/DefaultFileSystemProvider.java
--- a/src/java.base/aix/classes/sun/nio/fs/DefaultFileSystemProvider.java
+++ b/src/java.base/aix/classes/sun/nio/fs/DefaultFileSystemProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2018, 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
@@ -25,19 +25,29 @@
 
 package sun.nio.fs;
 
-import java.nio.file.spi.FileSystemProvider;
+import java.nio.file.FileSystem;
 
 /**
  * Creates this platform's default FileSystemProvider.
  */
 
 public class DefaultFileSystemProvider {
+    private static final AixFileSystemProvider INSTANCE
+        = new AixFileSystemProvider();
+
     private DefaultFileSystemProvider() { }
 
     /**
-     * Returns the default FileSystemProvider.
+     * Returns the platform's default file system provider.
      */
-    public static FileSystemProvider create() {
-        return new AixFileSystemProvider();
+    public static AixFileSystemProvider instance() {
+        return INSTANCE;
+    }
+
+    /**
+     * Returns the platform's default file system.
+     */
+    public static FileSystem theFileSystem() {
+        return INSTANCE.theFileSystem();
     }
 }
diff --git a/src/java.base/linux/classes/sun/nio/fs/DefaultFileSystemProvider.java b/src/java.base/linux/classes/sun/nio/fs/DefaultFileSystemProvider.java
--- a/src/java.base/linux/classes/sun/nio/fs/DefaultFileSystemProvider.java
+++ b/src/java.base/linux/classes/sun/nio/fs/DefaultFileSystemProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2018, 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
@@ -25,19 +25,29 @@
 
 package sun.nio.fs;
 
-import java.nio.file.spi.FileSystemProvider;
+import java.nio.file.FileSystem;
 
 /**
  * Creates this platform's default FileSystemProvider.
  */
 
 public class DefaultFileSystemProvider {
+    private static final LinuxFileSystemProvider INSTANCE
+        = new LinuxFileSystemProvider();
+
     private DefaultFileSystemProvider() { }
 
     /**
-     * Returns the default FileSystemProvider.
+     * Returns the platform's default file system provider.
      */
-    public static FileSystemProvider create() {
-        return new LinuxFileSystemProvider();
+    public static LinuxFileSystemProvider instance() {
+        return INSTANCE;
+    }
+
+    /**
+     * Returns the platform's default file system.
+     */
+    public static FileSystem theFileSystem() {
+        return INSTANCE.theFileSystem();
     }
 }
diff --git a/src/java.base/linux/classes/sun/nio/fs/LinuxFileSystemProvider.java b/src/java.base/linux/classes/sun/nio/fs/LinuxFileSystemProvider.java
--- a/src/java.base/linux/classes/sun/nio/fs/LinuxFileSystemProvider.java
+++ b/src/java.base/linux/classes/sun/nio/fs/LinuxFileSystemProvider.java
@@ -36,7 +36,7 @@
  * Linux implementation of FileSystemProvider
  */
 
-public class LinuxFileSystemProvider extends UnixFileSystemProvider {
+class LinuxFileSystemProvider extends UnixFileSystemProvider {
     public LinuxFileSystemProvider() {
         super();
     }
diff --git a/src/java.base/macosx/classes/sun/nio/fs/BsdFileSystemProvider.java b/src/java.base/macosx/classes/sun/nio/fs/BsdFileSystemProvider.java
--- a/src/java.base/macosx/classes/sun/nio/fs/BsdFileSystemProvider.java
+++ b/src/java.base/macosx/classes/sun/nio/fs/BsdFileSystemProvider.java
@@ -31,7 +31,7 @@
  * Bsd implementation of FileSystemProvider
  */
 
-public class BsdFileSystemProvider extends UnixFileSystemProvider {
+class BsdFileSystemProvider extends UnixFileSystemProvider {
     public BsdFileSystemProvider() {
         super();
     }
diff --git a/src/java.base/macosx/classes/sun/nio/fs/DefaultFileSystemProvider.java b/src/java.base/macosx/classes/sun/nio/fs/DefaultFileSystemProvider.java
--- a/src/java.base/macosx/classes/sun/nio/fs/DefaultFileSystemProvider.java
+++ b/src/java.base/macosx/classes/sun/nio/fs/DefaultFileSystemProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2018, 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
@@ -25,19 +25,29 @@
 
 package sun.nio.fs;
 
-import java.nio.file.spi.FileSystemProvider;
+import java.nio.file.FileSystem;
 
 /**
  * Creates this platform's default FileSystemProvider.
  */
 
 public class DefaultFileSystemProvider {
+    private static final MacOSXFileSystemProvider INSTANCE
+        = new MacOSXFileSystemProvider();
+
     private DefaultFileSystemProvider() { }
 
     /**
-     * Returns the default FileSystemProvider.
+     * Returns the platform's default file system provider.
      */
-    public static FileSystemProvider create() {
-        return new MacOSXFileSystemProvider();
+    public static MacOSXFileSystemProvider instance() {
+        return INSTANCE;
+    }
+
+    /**
+     * Returns the platform's default file system.
+     */
+    public static FileSystem theFileSystem() {
+        return INSTANCE.theFileSystem();
     }
 }
diff --git a/src/java.base/macosx/classes/sun/nio/fs/MacOSXFileSystemProvider.java b/src/java.base/macosx/classes/sun/nio/fs/MacOSXFileSystemProvider.java
--- a/src/java.base/macosx/classes/sun/nio/fs/MacOSXFileSystemProvider.java
+++ b/src/java.base/macosx/classes/sun/nio/fs/MacOSXFileSystemProvider.java
@@ -34,7 +34,7 @@
  * MacOSX implementation of FileSystemProvider
  */
 
-public class MacOSXFileSystemProvider extends BsdFileSystemProvider {
+class MacOSXFileSystemProvider extends BsdFileSystemProvider {
     public MacOSXFileSystemProvider() {
         super();
     }
diff --git a/src/java.base/share/classes/java/io/FilePermission.java b/src/java.base/share/classes/java/io/FilePermission.java
--- a/src/java.base/share/classes/java/io/FilePermission.java
+++ b/src/java.base/share/classes/java/io/FilePermission.java
@@ -25,7 +25,6 @@
 
 package java.io;
 
-import java.net.URI;
 import java.nio.file.*;
 import java.security.*;
 import java.util.Enumeration;
@@ -199,12 +198,11 @@
     private static final long serialVersionUID = 7930732926638008763L;
 
     /**
-     * Always use the internal default file system, in case it was modified
-     * with java.nio.file.spi.DefaultFileSystemProvider.
+     * Use the platform's default file system to avoid recursive initialization
+     * issues when the VM is configured to use a custom file system provider.
      */
     private static final java.nio.file.FileSystem builtInFS =
-            DefaultFileSystemProvider.create()
-                    .getFileSystem(URI.create("file:///"));
+        DefaultFileSystemProvider.theFileSystem();
 
     private static final Path here = builtInFS.getPath(
             GetPropertyAction.privilegedGetProperty("user.dir"));
@@ -326,7 +324,7 @@
 
             if (name.equals("<<ALL FILES>>")) {
                 allFiles = true;
-                npath = builtInFS.getPath("");
+                npath = EMPTY_PATH;
                 // other fields remain default
                 return;
             }
@@ -351,7 +349,7 @@
                     npath = npath.getParent();
                 }
                 if (npath == null) {
-                    npath = builtInFS.getPath("");
+                    npath = EMPTY_PATH;
                 }
                 invalid = false;
             } catch (InvalidPathException ipe) {
diff --git a/src/java.base/share/classes/java/nio/file/FileSystems.java b/src/java.base/share/classes/java/nio/file/FileSystems.java
--- a/src/java.base/share/classes/java/nio/file/FileSystems.java
+++ b/src/java.base/share/classes/java/nio/file/FileSystems.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 2018, 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
@@ -37,6 +37,7 @@
 import java.util.ServiceLoader;
 
 import jdk.internal.misc.VM;
+import sun.nio.fs.DefaultFileSystemProvider;
 
 /**
  * Factory methods for file systems. This class defines the {@link #getDefault
@@ -88,16 +89,6 @@
 public final class FileSystems {
     private FileSystems() { }
 
-    // Built-in file system provider
-    private static final FileSystemProvider builtinFileSystemProvider =
-        sun.nio.fs.DefaultFileSystemProvider.create();
-
-    // built-in file system
-    private static class BuiltinFileSystemHolder {
-        static final FileSystem builtinFileSystem =
-            builtinFileSystemProvider.getFileSystem(URI.create("file:///"));
-    }
-
     // lazy initialization of default file system
     private static class DefaultFileSystemHolder {
         static final FileSystem defaultFileSystem = defaultFileSystem();
@@ -118,7 +109,8 @@
 
         // returns default provider
         private static FileSystemProvider getDefaultProvider() {
-            FileSystemProvider provider = builtinFileSystemProvider;
+            // start with the platform's default file system provider
+            FileSystemProvider provider = DefaultFileSystemProvider.instance();
 
             // if the property java.nio.file.spi.DefaultFileSystemProvider is
             // set then its value is the name of the default provider (or a list)
@@ -189,7 +181,8 @@
         if (VM.isModuleSystemInited()) {
             return DefaultFileSystemHolder.defaultFileSystem;
         } else {
-            return BuiltinFileSystemHolder.builtinFileSystem;
+            // always use the platform's default file system during startup
+            return DefaultFileSystemProvider.theFileSystem();
         }
     }
 
diff --git a/src/java.base/solaris/classes/sun/nio/fs/DefaultFileSystemProvider.java b/src/java.base/solaris/classes/sun/nio/fs/DefaultFileSystemProvider.java
--- a/src/java.base/solaris/classes/sun/nio/fs/DefaultFileSystemProvider.java
+++ b/src/java.base/solaris/classes/sun/nio/fs/DefaultFileSystemProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2018, 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
@@ -25,19 +25,29 @@
 
 package sun.nio.fs;
 
-import java.nio.file.spi.FileSystemProvider;
+import java.nio.file.FileSystem;
 
 /**
  * Creates this platform's default FileSystemProvider.
  */
 
 public class DefaultFileSystemProvider {
+    private static final SolarisFileSystemProvider INSTANCE
+        = new SolarisFileSystemProvider();
+
     private DefaultFileSystemProvider() { }
 
     /**
-     * Returns the default FileSystemProvider.
+     * Returns the platform's default file system provider.
      */
-    public static FileSystemProvider create() {
-        return new SolarisFileSystemProvider();
+    public static SolarisFileSystemProvider instance() {
+        return INSTANCE;
+    }
+
+    /**
+     * Returns the platform's default file system.
+     */
+    public static FileSystem theFileSystem() {
+        return INSTANCE.theFileSystem();
     }
 }
diff --git a/src/java.base/solaris/classes/sun/nio/fs/SolarisFileSystemProvider.java b/src/java.base/solaris/classes/sun/nio/fs/SolarisFileSystemProvider.java
--- a/src/java.base/solaris/classes/sun/nio/fs/SolarisFileSystemProvider.java
+++ b/src/java.base/solaris/classes/sun/nio/fs/SolarisFileSystemProvider.java
@@ -36,7 +36,7 @@
  * Solaris implementation of FileSystemProvider
  */
 
-public class SolarisFileSystemProvider extends UnixFileSystemProvider {
+class SolarisFileSystemProvider extends UnixFileSystemProvider {
     public SolarisFileSystemProvider() {
         super();
     }
diff --git a/src/java.base/unix/classes/sun/nio/fs/UnixFileSystemProvider.java b/src/java.base/unix/classes/sun/nio/fs/UnixFileSystemProvider.java
--- a/src/java.base/unix/classes/sun/nio/fs/UnixFileSystemProvider.java
+++ b/src/java.base/unix/classes/sun/nio/fs/UnixFileSystemProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2018, 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
@@ -56,6 +56,10 @@
         theFileSystem = newFileSystem(userDir);
     }
 
+    UnixFileSystem theFileSystem() {
+        return theFileSystem;
+    }
+
     /**
      * Constructs a new file system using the given default directory.
      */
diff --git a/src/java.base/windows/classes/sun/nio/fs/DefaultFileSystemProvider.java b/src/java.base/windows/classes/sun/nio/fs/DefaultFileSystemProvider.java
--- a/src/java.base/windows/classes/sun/nio/fs/DefaultFileSystemProvider.java
+++ b/src/java.base/windows/classes/sun/nio/fs/DefaultFileSystemProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2018, 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
@@ -25,14 +25,28 @@
 
 package sun.nio.fs;
 
-import java.nio.file.spi.FileSystemProvider;
+import java.nio.file.FileSystem;
 
 /**
- * Creates default provider on Windows
+ * Creates this platform's default FileSystemProvider.
  */
 public class DefaultFileSystemProvider {
+    private static final WindowsFileSystemProvider INSTANCE
+        = new WindowsFileSystemProvider();
+
     private DefaultFileSystemProvider() { }
-    public static FileSystemProvider create() {
-        return new WindowsFileSystemProvider();
+
+    /**
+     * Returns the platform's default file system provider.
+     */
+    public static WindowsFileSystemProvider instance() {
+        return INSTANCE;
+    }
+
+    /**
+     * Returns the platform's default file system.
+     */
+    public static FileSystem theFileSystem() {
+        return INSTANCE.theFileSystem();
     }
 }
diff --git a/src/java.base/windows/classes/sun/nio/fs/WindowsFileSystemProvider.java b/src/java.base/windows/classes/sun/nio/fs/WindowsFileSystemProvider.java
--- a/src/java.base/windows/classes/sun/nio/fs/WindowsFileSystemProvider.java
+++ b/src/java.base/windows/classes/sun/nio/fs/WindowsFileSystemProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2018, 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
@@ -42,7 +42,7 @@
 import static sun.nio.fs.WindowsSecurity.*;
 import static sun.nio.fs.WindowsConstants.*;
 
-public class WindowsFileSystemProvider
+class WindowsFileSystemProvider
     extends AbstractFileSystemProvider
 {
     private static final Unsafe unsafe = Unsafe.getUnsafe();
@@ -53,6 +53,10 @@
         theFileSystem = new WindowsFileSystem(this, StaticProperty.userDir());
     }
 
+    WindowsFileSystem theFileSystem() {
+        return theFileSystem;
+    }
+
     @Override
     public String getScheme() {
         return "file";