8266369: (se) Add wepoll based Selector

Reviewed-by: chegar, michaelm, vtewari, dfuchs, bpb

src/java.base/share/classes/sun/nio/ch/Net.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2021, 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
@@ -679,6 +679,10 @@ static boolean pollConnectNow(FileDescriptor fd) throws IOException {
      */
     static native int sendOOB(FileDescriptor fd, byte data) throws IOException;
 
+    /**
+     * Read and discard urgent data (MSG_OOB) on the socket.
+     */
+    static native boolean discardOOB(FileDescriptor fd) throws IOException;
 
     // -- Multicast support --
 

src/java.base/share/classes/sun/nio/ch/SelectionKeyImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2021, 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
@@ -25,6 +25,7 @@
 
 package sun.nio.ch;
 
+import java.io.FileDescriptor;
 import java.lang.invoke.ConstantBootstraps;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
@@ -74,6 +75,10 @@ private void ensureValid() {
             throw new CancelledKeyException();
     }
 
+    FileDescriptor getFD() {
+        return channel.getFD();
+    }
+
     int getFDVal() {
         return channel.getFDVal();
     }

src/java.base/windows/classes/sun/nio/ch/DefaultSelectorProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2021, 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
@@ -35,7 +35,7 @@
 public class DefaultSelectorProvider {
     private static final SelectorProviderImpl INSTANCE;
     static {
-        PrivilegedAction<SelectorProviderImpl> pa = WindowsSelectorProvider::new;
+        PrivilegedAction<SelectorProviderImpl> pa = WEPollSelectorProvider::new;
         INSTANCE = AccessController.doPrivileged(pa);
     }
 

src/java.base/windows/classes/sun/nio/ch/PipeImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2021, 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
@@ -61,10 +61,10 @@ class PipeImpl
     private static final Random RANDOM_NUMBER_GENERATOR = new SecureRandom();
 
     // Source and sink channels
-    private final SourceChannel source;
-    private final SinkChannel sink;
+    private final SourceChannelImpl source;
+    private final SinkChannelImpl sink;
 
-    private class Initializer
+    private static class Initializer
         implements PrivilegedExceptionAction<Void>
     {
 
@@ -203,11 +203,11 @@ public void run() {
         this.sink = initializer.sink;
     }
 
-    public SourceChannel source() {
+    public SourceChannelImpl source() {
         return source;
     }
 
-    public SinkChannel sink() {
+    public SinkChannelImpl sink() {
         return sink;
     }
 

src/java.base/windows/classes/sun/nio/ch/WEPoll.java

@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2020, 2021, 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
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.nio.ch;
+
+import java.io.IOException;
+import jdk.internal.misc.Unsafe;
+
+/**
+ * Provides access to wepoll.
+ */
+class WEPoll {
+    private static final Unsafe UNSAFE = Unsafe.getUnsafe();
+    private static final int ADDRESS_SIZE = UNSAFE.addressSize();
+
+    private WEPoll() { }
+
+    /**
+     * typedef union epoll_data {
+     *     void *ptr;
+     *     int fd;
+     *     uint32_t u32;
+     *     uint64_t u64;
+     *     SOCKET sock;   // Windows specific
+     *     HANDLE hnd;    // Windows specific
+     *  } epoll_data_t;
+     *
+     * struct epoll_event {
+     *     uint32_t events;
+     *     epoll_data_t data;
+     * }
+     */
+    private static final int SIZEOF_EPOLLEVENT   = eventSize();
+    private static final int OFFSETOF_EVENTS     = eventsOffset();
+    private static final int OFFSETOF_SOCK       = dataOffset();
+
+    // opcodes
+    static final int EPOLL_CTL_ADD  = 1;
+    static final int EPOLL_CTL_MOD  = 2;
+    static final int EPOLL_CTL_DEL  = 3;
+
+    // events
+    static final int EPOLLIN   = (1 << 0);
+    static final int EPOLLPRI  = (1 << 1);
+    static final int EPOLLOUT  = (1 << 2);
+    static final int EPOLLERR  = (1 << 3);
+    static final int EPOLLHUP  = (1 << 4);
+
+    // flags
+    static final int EPOLLONESHOT = (1 << 31);
+
+    /**
+     * Allocates a poll array to handle up to {@code count} events.
+     */
+    static long allocatePollArray(int count) {
+        long size = (long) count * SIZEOF_EPOLLEVENT;
+        long base = UNSAFE.allocateMemory(size);
+        UNSAFE.setMemory(base, size, (byte) 0);
+        return base;
+    }
+
+    /**
+     * Free a poll array
+     */
+    static void freePollArray(long address) {
+        UNSAFE.freeMemory(address);
+    }
+
+    /**
+     * Returns event[i];
+     */
+    static long getEvent(long address, int i) {
+        return address + (SIZEOF_EPOLLEVENT*i);
+    }
+
+    /**
+     * Returns event->data.socket
+     */
+    static long getSocket(long eventAddress) {
+        if (ADDRESS_SIZE == 8) {
+            return UNSAFE.getLong(eventAddress + OFFSETOF_SOCK);
+        } else {
+            return UNSAFE.getInt(eventAddress + OFFSETOF_SOCK);
+        }
+    }
+
+    /**
+     * Return event->data.socket as an int file descriptor
+     */
+    static int getDescriptor(long eventAddress) {
+        long s = getSocket(eventAddress);
+        int fd = (int) s;
+        assert ((long) fd) == s;
+        return fd;
+    }
+
+    /**
+     * Returns event->events
+     */
+    static int getEvents(long eventAddress) {
+        return UNSAFE.getInt(eventAddress + OFFSETOF_EVENTS);
+    }
+
+    // -- Native methods --
+
+    private static native int eventSize();
+
+    private static native int eventsOffset();
+
+    private static native int dataOffset();
+
+    static native long create() throws IOException;
+
+    static native int ctl(long h, int opcode, long s, int events);
+
+    static native int wait(long h, long pollAddress, int numfds, int timeout)
+        throws IOException;
+
+    static native void close(long h);
+
+    static {
+        IOUtil.load();
+    }
+}