Skip to content

8351458: (ch) Move preClose to UnixDispatcher #23956

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

8351458: (ch) Move preClose to UnixDispatcher #23956

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 2 additions & 17 deletions src/java.base/share/classes/sun/nio/ch/DatagramChannelImpl.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2001, 2024, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2001, 2025, 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
Expand Down Expand Up @@ -1756,22 +1756,7 @@ private void implCloseBlockingMode() throws IOException {
registry.invalidateAll();

if (!tryClose()) {
long reader = readerThread;
long writer = writerThread;
if (reader != 0 || writer != 0) {
if (NativeThread.isVirtualThread(reader)
|| NativeThread.isVirtualThread(writer)) {
Poller.stopPoll(fdVal);
}
if (NativeThread.isNativeThread(reader)
|| NativeThread.isNativeThread(writer)) {
nd.preClose(fd);
if (NativeThread.isNativeThread(reader))
NativeThread.signal(reader);
if (NativeThread.isNativeThread(writer))
NativeThread.signal(writer);
}
}
nd.preClose(fd, readerThread, writerThread);
}
}
}
Expand Down
32 changes: 26 additions & 6 deletions src/java.base/share/classes/sun/nio/ch/NativeDispatcher.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2025, 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
Expand Down Expand Up @@ -27,13 +27,16 @@

import java.io.FileDescriptor;
import java.io.IOException;
import jdk.internal.access.JavaIOFileDescriptorAccess;
import jdk.internal.access.SharedSecrets;

/**
* Allows different platforms to call different native methods
* for read and write operations.
*/

abstract class NativeDispatcher {
private static final JavaIOFileDescriptorAccess JIOFDA = SharedSecrets.getJavaIOFileDescriptorAccess();

abstract int read(FileDescriptor fd, long address, int len)
throws IOException;
Expand Down Expand Up @@ -69,11 +72,28 @@ abstract long writev(FileDescriptor fd, long address, int len)

abstract void close(FileDescriptor fd) throws IOException;

// Prepare the given fd for closing by duping it to a known internal fd
// that's already closed. This is necessary on some operating systems
// (Solaris and Linux) to prevent fd recycling.
//
void preClose(FileDescriptor fd) throws IOException {
/**
* Prepare the given file descriptor for closing. If a virtual thread is blocked
* on the file descriptor then it is unparked so that it stops polling. On Unix systems,
* if a platform thread is blocked on the file descriptor then the file descriptor is
* dup'ed to a special fd and the thread signalled so that the syscall fails with EINTR.
*/
final void preClose(FileDescriptor fd, long reader, long writer) throws IOException {
if (NativeThread.isVirtualThread(reader) || NativeThread.isVirtualThread(writer)) {
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

There used to be a if (reader != 0 || writer != 0) {...} check before doing any of this pre-close work, in DatagramChannelImpl. Is that no longer needed?

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

There used to be a if (reader != 0 || writer != 0) {...} check before doing any of this pre-close work, in DatagramChannelImpl. Is that no longer needed?

Looking at the implementation of NativeThread.isNativeThread() and NativeThread.isVirtualThread(), it already implicitly takes into account the != 0 check, so I guess the previous explicit checks before calling those methods was redundant.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Right, there are a several places where check for != 0 would be redundant.

int fdVal = JIOFDA.get(fd);
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Hello Alan, previously, in the case of DatagramChannelImpl, the fdVal was a final that was determined when the channel was constructed. Now, that fdVal gets determined as and when needed and I see that FileDescriptor allows this underlying value to be changed/reset. Is there anything practical to consider here in context of a fdVal that has been reset in the FileDescriptor?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

repairSocket doesn't change fd/fdVal, instead they will be connected to a new socket if the method succeeds (or the old socket if it fails).

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It was the FileDescriptor.set(int fd) method which I had in mind. But I now looked at its references and I see that there aren't any in the code paths that this PR deals with. So I believe the proposed change looks good.

Poller.stopPoll(fdVal);
}
if (NativeThread.isNativeThread(reader) || NativeThread.isNativeThread(writer)) {
implPreClose(fd, reader, writer);
}
}

/**
* This method does nothing by default. On Unix systems the file descriptor is dup'ed
* to a special fd and native threads signalled.
*/

void implPreClose(FileDescriptor fd, long reader, long writer) throws IOException {
// Do nothing by default; this is only needed on Unix
}

Expand Down
17 changes: 2 additions & 15 deletions src/java.base/share/classes/sun/nio/ch/NioSocketImpl.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2019, 2024, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2019, 2025, 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
Expand Down Expand Up @@ -894,20 +894,7 @@ protected void close() throws IOException {
// then the socket is pre-closed and the thread(s) signalled. The
// last thread will close the file descriptor.
if (!tryClose()) {
long reader = readerThread;
long writer = writerThread;
if (NativeThread.isVirtualThread(reader)
|| NativeThread.isVirtualThread(writer)) {
Poller.stopPoll(fdVal(fd));
}
if (NativeThread.isNativeThread(reader)
|| NativeThread.isNativeThread(writer)) {
nd.preClose(fd);
if (NativeThread.isNativeThread(reader))
NativeThread.signal(reader);
if (NativeThread.isNativeThread(writer))
NativeThread.signal(writer);
}
nd.preClose(fd, readerThread, writerThread);
}
}
}
Expand Down
12 changes: 2 additions & 10 deletions src/java.base/share/classes/sun/nio/ch/ServerSocketChannelImpl.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2024, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2025, 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
Expand Down Expand Up @@ -585,15 +585,7 @@ private void implCloseBlockingMode() throws IOException {
assert state < ST_CLOSING;
state = ST_CLOSING;
if (!tryClose()) {
long th = thread;
if (th != 0) {
if (NativeThread.isVirtualThread(th)) {
Poller.stopPoll(fdVal);
} else {
nd.preClose(fd);
NativeThread.signal(th);
}
}
nd.preClose(fd, thread, 0);
}
}
}
Expand Down
18 changes: 3 additions & 15 deletions src/java.base/share/classes/sun/nio/ch/SocketChannelImpl.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2024, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2025, 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
Expand Down Expand Up @@ -1123,20 +1123,8 @@ private void implCloseBlockingMode() throws IOException {
} catch (IOException ignore) { }
}

long reader = readerThread;
long writer = writerThread;
if (NativeThread.isVirtualThread(reader)
|| NativeThread.isVirtualThread(writer)) {
Poller.stopPoll(fdVal);
}
if (NativeThread.isNativeThread(reader)
|| NativeThread.isNativeThread(writer)) {
nd.preClose(fd);
if (NativeThread.isNativeThread(reader))
NativeThread.signal(reader);
if (NativeThread.isNativeThread(writer))
NativeThread.signal(writer);
}
// prepare file descriptor for closing
nd.preClose(fd, readerThread, writerThread);
}
}
}
Expand Down
25 changes: 11 additions & 14 deletions src/java.base/unix/classes/sun/nio/ch/DatagramDispatcher.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2001, 2022, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2001, 2025, 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
Expand Down Expand Up @@ -39,46 +39,43 @@ class DatagramDispatcher extends UnixDispatcher {
IOUtil.load();
}

@Override
int read(FileDescriptor fd, long address, int len) throws IOException {
return read0(fd, address, len);
}

@Override
long readv(FileDescriptor fd, long address, int len) throws IOException {
return readv0(fd, address, len);
}

@Override
int write(FileDescriptor fd, long address, int len) throws IOException {
return write0(fd, address, len);
}

@Override
long writev(FileDescriptor fd, long address, int len) throws IOException {
return writev0(fd, address, len);
}

void close(FileDescriptor fd) throws IOException {
close0(fd);
}

void preClose(FileDescriptor fd) throws IOException {
preClose0(fd);
}

@Override
void dup(FileDescriptor fd1, FileDescriptor fd2) throws IOException {
dup0(fd1, fd2);
}

static native int read0(FileDescriptor fd, long address, int len)
private static native int read0(FileDescriptor fd, long address, int len)
throws IOException;

static native long readv0(FileDescriptor fd, long address, int len)
private static native long readv0(FileDescriptor fd, long address, int len)
throws IOException;

static native int write0(FileDescriptor fd, long address, int len)
private static native int write0(FileDescriptor fd, long address, int len)
throws IOException;

static native long writev0(FileDescriptor fd, long address, int len)
private static native long writev0(FileDescriptor fd, long address, int len)
throws IOException;

static native void dup0(FileDescriptor fd1, FileDescriptor fd2)
private static native void dup0(FileDescriptor fd1, FileDescriptor fd2)
throws IOException;
}
14 changes: 3 additions & 11 deletions src/java.base/unix/classes/sun/nio/ch/SinkChannelImpl.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2024, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2025, 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
Expand Down Expand Up @@ -42,7 +42,7 @@ class SinkChannelImpl
implements SelChImpl
{
// Used to make native read and write calls
private static final NativeDispatcher nd = new FileDispatcherImpl();
private static final NativeDispatcher nd = new SocketDispatcher();

// The file descriptor associated with this channel
private final FileDescriptor fd;
Expand Down Expand Up @@ -152,15 +152,7 @@ private void implCloseBlockingMode() throws IOException {
assert state < ST_CLOSING;
state = ST_CLOSING;
if (!tryClose()) {
long th = thread;
if (th != 0) {
if (NativeThread.isVirtualThread(th)) {
Poller.stopPoll(fdVal);
} else {
nd.preClose(fd);
NativeThread.signal(th);
}
}
nd.preClose(fd, thread, 0);
}
}
}
Expand Down
18 changes: 7 additions & 11 deletions src/java.base/unix/classes/sun/nio/ch/SocketDispatcher.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2022, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2025, 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
Expand Down Expand Up @@ -43,6 +43,7 @@ class SocketDispatcher extends UnixDispatcher {
* @throws sun.net.ConnectionResetException if connection reset is detected
* @throws IOException if another I/O error occurs
*/
@Override
int read(FileDescriptor fd, long address, int len) throws IOException {
return read0(fd, address, len);
}
Expand All @@ -54,26 +55,21 @@ int read(FileDescriptor fd, long address, int len) throws IOException {
* @throws sun.net.ConnectionResetException if connection reset is detected
* @throws IOException if another I/O error occurs
*/
@Override
long readv(FileDescriptor fd, long address, int len) throws IOException {
return readv0(fd, address, len);
}

@Override
int write(FileDescriptor fd, long address, int len) throws IOException {
return write0(fd, address, len);
}

@Override
long writev(FileDescriptor fd, long address, int len) throws IOException {
return writev0(fd, address, len);
}

void close(FileDescriptor fd) throws IOException {
close0(fd);
}

void preClose(FileDescriptor fd) throws IOException {
preClose0(fd);
}

// -- Native methods --

private static native int read0(FileDescriptor fd, long address, int len)
Expand All @@ -82,10 +78,10 @@ private static native int read0(FileDescriptor fd, long address, int len)
private static native long readv0(FileDescriptor fd, long address, int len)
throws IOException;

static native int write0(FileDescriptor fd, long address, int len)
private static native int write0(FileDescriptor fd, long address, int len)
throws IOException;

static native long writev0(FileDescriptor fd, long address, int len)
private static native long writev0(FileDescriptor fd, long address, int len)
throws IOException;

static {
Expand Down
14 changes: 3 additions & 11 deletions src/java.base/unix/classes/sun/nio/ch/SourceChannelImpl.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2024, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2025, 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
Expand Down Expand Up @@ -42,7 +42,7 @@ class SourceChannelImpl
implements SelChImpl
{
// Used to make native read and write calls
private static final NativeDispatcher nd = new FileDispatcherImpl();
private static final NativeDispatcher nd = new SocketDispatcher();

// The file descriptor associated with this channel
private final FileDescriptor fd;
Expand Down Expand Up @@ -152,15 +152,7 @@ private void implCloseBlockingMode() throws IOException {
assert state < ST_CLOSING;
state = ST_CLOSING;
if (!tryClose()) {
long th = thread;
if (th != 0) {
if (NativeThread.isVirtualThread(th)) {
Poller.stopPoll(fdVal);
} else {
nd.preClose(fd);
NativeThread.signal(th);
}
}
nd.preClose(fd, thread, 0);
}
}
}
Expand Down
14 changes: 10 additions & 4 deletions src/java.base/unix/classes/sun/nio/ch/UnixDispatcher.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2022, 2025, 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
Expand Down Expand Up @@ -30,17 +30,23 @@

abstract class UnixDispatcher extends NativeDispatcher {

@Override
void close(FileDescriptor fd) throws IOException {
close0(fd);
}

void preClose(FileDescriptor fd) throws IOException {
@Override
void implPreClose(FileDescriptor fd, long reader, long writer) throws IOException {
preClose0(fd);
if (NativeThread.isNativeThread(reader))
NativeThread.signal(reader);
if (NativeThread.isNativeThread(writer))
NativeThread.signal(writer);
}

static native void close0(FileDescriptor fd) throws IOException;
private static native void close0(FileDescriptor fd) throws IOException;

static native void preClose0(FileDescriptor fd) throws IOException;
private static native void preClose0(FileDescriptor fd) throws IOException;

static native void init();

Expand Down
Loading