8168640: (fc) Avoiding AtomicBoolean in FileInput/-OutputStream improves startup
Reviewed-by: alanb, plevart
--- a/jdk/src/java.base/share/classes/java/io/FileInputStream.java Wed Oct 26 09:38:16 2016 -0400
+++ b/jdk/src/java.base/share/classes/java/io/FileInputStream.java Wed Oct 26 17:50:08 2016 +0200
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
+ * 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
@@ -26,7 +26,6 @@
package java.io;
import java.nio.channels.FileChannel;
-import java.util.concurrent.atomic.AtomicBoolean;
import sun.nio.ch.FileChannelImpl;
@@ -60,7 +59,9 @@
private volatile FileChannel channel;
- private final AtomicBoolean closed = new AtomicBoolean(false);
+ private final Object closeLock = new Object();
+
+ private volatile boolean closed;
/**
* Creates a <code>FileInputStream</code> by
@@ -313,14 +314,21 @@
* @spec JSR-51
*/
public void close() throws IOException {
- if (!closed.compareAndSet(false, true)) {
- // if compareAndSet() returns false closed was already true
+ if (closed) {
return;
}
+ synchronized (closeLock) {
+ if (closed) {
+ return;
+ }
+ closed = true;
+ }
FileChannel fc = channel;
if (fc != null) {
- fc.close();
+ // possible race with getChannel(), benign since
+ // FileChannel.close is final and idempotent
+ fc.close();
}
fd.closeAll(new Closeable() {
@@ -370,8 +378,10 @@
fc = this.channel;
if (fc == null) {
this.channel = fc = FileChannelImpl.open(fd, path, true, false, this);
- if (closed.get()) {
+ 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
--- a/jdk/src/java.base/share/classes/java/io/FileOutputStream.java Wed Oct 26 09:38:16 2016 -0400
+++ b/jdk/src/java.base/share/classes/java/io/FileOutputStream.java Wed Oct 26 17:50:08 2016 +0200
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
+ * 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
@@ -26,7 +26,6 @@
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;
@@ -77,7 +76,9 @@
*/
private final String path;
- private final AtomicBoolean closed = new AtomicBoolean(false);
+ private final Object closeLock = new Object();
+
+ private volatile boolean closed;
/**
* Creates a file output stream to write to the file with the
@@ -341,14 +342,21 @@
* @spec JSR-51
*/
public void close() throws IOException {
- if (!closed.compareAndSet(false, true)) {
- // if compareAndSet() returns false closed was already true
+ if (closed) {
return;
}
+ synchronized (closeLock) {
+ if (closed) {
+ return;
+ }
+ closed = true;
+ }
FileChannel fc = channel;
if (fc != null) {
- fc.close();
+ // possible race with getChannel(), benign since
+ // FileChannel.close is final and idempotent
+ fc.close();
}
fd.closeAll(new Closeable() {
@@ -399,8 +407,10 @@
fc = this.channel;
if (fc == null) {
this.channel = fc = FileChannelImpl.open(fd, path, false, true, this);
- if (closed.get()) {
+ 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