8192939: Remove Finalize methods from FileInputStream and FileOutputStream

Reviewed-by: alanb, iris, mchung
This commit is contained in:
Roger Riggs 2018-10-16 10:55:28 -04:00
parent 794d864feb
commit 8dd0b1f061
4 changed files with 48 additions and 299 deletions

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 1994, 2017, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1994, 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
@ -79,8 +79,6 @@ class FileInputStream extends InputStream
private volatile boolean closed;
private final Object altFinalizer;
/**
* Creates a <code>FileInputStream</code> by
* opening a connection to an actual file,
@ -155,10 +153,7 @@ class FileInputStream extends InputStream
fd.attach(this);
path = name;
open(name);
altFinalizer = getFinalizer(this);
if (altFinalizer == null) {
FileCleanable.register(fd); // open set the fd, register the cleanup
}
FileCleanable.register(fd); // open set the fd, register the cleanup
}
/**
@ -195,7 +190,6 @@ class FileInputStream extends InputStream
}
fd = fdObj;
path = null;
altFinalizer = null;
/*
* FileDescriptor is being shared by streams.
@ -438,85 +432,4 @@ class FileInputStream extends InputStream
static {
initIDs();
}
/**
* Ensures that the {@link #close} method of this file input stream is
* called when there are no more references to it.
* The {@link #finalize} method does not call {@link #close} directly.
*
* @apiNote
* To release resources used by this stream {@link #close} should be called
* directly or by try-with-resources.
*
* @implSpec
* If this FileInputStream has been subclassed and the {@link #close}
* method has been overridden, the {@link #close} method will be
* called when the FileInputStream is unreachable.
* Otherwise, it is implementation specific how the resource cleanup described in
* {@link #close} is performed.
*
* @deprecated The {@code finalize} method has been deprecated and will be removed.
* Subclasses that override {@code finalize} in order to perform cleanup
* should be modified to use alternative cleanup mechanisms and
* to remove the overriding {@code finalize} method.
* When overriding the {@code finalize} method, its implementation must explicitly
* ensure that {@code super.finalize()} is invoked as described in {@link Object#finalize}.
* See the specification for {@link Object#finalize()} for further
* information about migration options.
*
* @exception IOException if an I/O error occurs.
* @see java.io.FileInputStream#close()
*/
@Deprecated(since="9", forRemoval = true)
protected void finalize() throws IOException {
}
/*
* Returns a finalizer object if the FIS needs a finalizer; otherwise null.
* If the FIS has a close method; it needs an AltFinalizer.
*/
private static Object getFinalizer(FileInputStream fis) {
Class<?> clazz = fis.getClass();
while (clazz != FileInputStream.class) {
try {
clazz.getDeclaredMethod("close");
return new AltFinalizer(fis);
} catch (NoSuchMethodException nsme) {
// ignore
}
clazz = clazz.getSuperclass();
}
return null;
}
/**
* Class to call {@code FileInputStream.close} when finalized.
* If finalization of the stream is needed, an instance is created
* in its constructor(s). When the set of instances
* related to the stream is unreachable, the AltFinalizer performs
* the needed call to the stream's {@code close} method.
*/
static class AltFinalizer {
private final FileInputStream fis;
AltFinalizer(FileInputStream fis) {
this.fis = fis;
}
@Override
@SuppressWarnings("deprecation")
protected final void finalize() {
try {
if ((fis.fd != null) && (fis.fd != FileDescriptor.in)) {
/* if fd is shared, the references in FileDescriptor
* will ensure that finalizer is only called when
* safe to do so. All references using the fd have
* become unreachable. We can call close()
*/
fis.close();
}
} catch (IOException ioe) {
// ignore
}
}
}
}