/*
* Copyright (c) 2001, 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
* 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.lang.annotation.Native;
/**
* Manipulates a native array of structs corresponding to (fd, events) pairs.
*
* typedef struct pollfd {
* SOCKET fd; // 4 bytes
* short events; // 2 bytes
* } pollfd_t;
*
* @author Konstantin Kladko
* @author Mike McCloskey
*/
class PollArrayWrapper {
private AllocatedNativeObject pollArray; // The fd array
long pollArrayAddress; // pollArrayAddress
@Native private static final short FD_OFFSET = 0; // fd offset in pollfd
@Native private static final short EVENT_OFFSET = 4; // events offset in pollfd
static short SIZE_POLLFD = 8; // sizeof pollfd struct
private int size; // Size of the pollArray
PollArrayWrapper(int newSize) {
int allocationSize = newSize * SIZE_POLLFD;
pollArray = new AllocatedNativeObject(allocationSize, true);
pollArrayAddress = pollArray.address();
this.size = newSize;
}
// Prepare another pollfd struct for use.
void putEntry(int index, SelectionKeyImpl ski) {
putDescriptor(index, ski.getFDVal());
putEventOps(index, 0);
}
// Writes the pollfd entry from the source wrapper at the source index
// over the entry in the target wrapper at the target index.
void replaceEntry(PollArrayWrapper source, int sindex,
PollArrayWrapper target, int tindex) {
target.putDescriptor(tindex, source.getDescriptor(sindex));
target.putEventOps(tindex, source.getEventOps(sindex));
}
// Grows the pollfd array to new size
void grow(int newSize) {
PollArrayWrapper temp = new PollArrayWrapper(newSize);
for (int i = 0; i < size; i++)
replaceEntry(this, i, temp, i);
pollArray.free();
pollArray = temp.pollArray;
this.size = temp.size;
pollArrayAddress = pollArray.address();
}
void free() {
pollArray.free();
}
// Access methods for fd structures
void putDescriptor(int i, int fd) {
pollArray.putInt(SIZE_POLLFD * i + FD_OFFSET, fd);
}
void putEventOps(int i, int event) {
pollArray.putShort(SIZE_POLLFD * i + EVENT_OFFSET, (short)event);
}
/**代码未完, 请加载全部代码(NowJava.com).**/