src/java.base/share/classes/java/io/FileOutputStream.java

rev 15897 : 8168640: (fc) Avoiding AtomicBoolean in FileInput/-OutputStream improves startup
Reviewed-by: alanb, shade, plevart

*** 1,7 ****
  /*
!  * Copyright (c) 1994, 2013, 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.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 1994, 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.  Oracle designates this
*** 24,34 ****
   */
  
  package java.io;
  
  import java.nio.channels.FileChannel;
- import java.util.concurrent.atomic.AtomicBoolean;
  import jdk.internal.misc.SharedSecrets;
  import jdk.internal.misc.JavaIOFileDescriptorAccess;
  import sun.nio.ch.FileChannelImpl;
  
  
--- 24,33 ----
*** 75,85 ****
       * The path of the referenced file
       * (null if the stream is created with a file descriptor)
       */
      private final String path;
  
!     private final AtomicBoolean closed = new AtomicBoolean(false);
  
      /**
       * Creates a file output stream to write to the file with the
       * specified name. A new <code>FileDescriptor</code> object is
       * created to represent this file connection.
--- 74,86 ----
       * The path of the referenced file
       * (null if the stream is created with a file descriptor)
       */
      private final String path;
  
!     private final Object closeLock = new Object();
! 
!     private volatile boolean closed;
  
      /**
       * Creates a file output stream to write to the file with the
       * specified name. A new <code>FileDescriptor</code> object is
       * created to represent this file connection.
*** 339,355 ****
       *
       * @revised 1.4
       * @spec JSR-51
       */
      public void close() throws IOException {
!         if (!closed.compareAndSet(false, true)) {
!             // if compareAndSet() returns false closed was already true
              return;
          }
  
          FileChannel fc = channel;
          if (fc != null) {
             fc.close();
          }
  
          fd.closeAll(new Closeable() {
              public void close() throws IOException {
--- 340,363 ----
       *
       * @revised 1.4
       * @spec JSR-51
       */
      public void close() throws IOException {
!         if (closed) {
!             return;
!         }
!         synchronized (closeLock) {
!             if (closed) {
                  return;
              }
+             closed = true;
+         }
  
          FileChannel fc = channel;
          if (fc != null) {
+             // possible race with getChannel(), benign since
+             // FileChannel.close is final and idempotent
              fc.close();
          }
  
          fd.closeAll(new Closeable() {
              public void close() throws IOException {
*** 397,408 ****
          if (fc == null) {
              synchronized (this) {
                  fc = this.channel;
                  if (fc == null) {
                      this.channel = fc = FileChannelImpl.open(fd, path, false, true, this);
!                     if (closed.get()) {
                          try {
                              fc.close();
                          } catch (IOException ioe) {
                              throw new InternalError(ioe); // should not happen
                          }
                      }
--- 405,418 ----
          if (fc == null) {
              synchronized (this) {
                  fc = this.channel;
                  if (fc == null) {
                      this.channel = fc = FileChannelImpl.open(fd, path, false, true, this);
!                     if (closed) {
                          try {
+                             // possible race with close(), benign since
+                             // FileChannel.close is final and idempotent
                              fc.close();
                          } catch (IOException ioe) {
                              throw new InternalError(ioe); // should not happen
                          }
                      }