--- a/src/java.base/linux/classes/sun/nio/ch/EPollArrayWrapper.java Fri Mar 23 11:18:39 2018 +0530
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,309 +0,0 @@
-/*
- * Copyright (c) 2005, 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.io.IOException;
-import java.security.AccessController;
-import java.util.BitSet;
-import java.util.HashMap;
-import java.util.Map;
-import sun.security.action.GetIntegerAction;
-
-/**
- * Manipulates a native array of epoll_event structs on Linux:
- *
- * typedef union epoll_data {
- * void *ptr;
- * int fd;
- * __uint32_t u32;
- * __uint64_t u64;
- * } epoll_data_t;
- *
- * struct epoll_event {
- * __uint32_t events;
- * epoll_data_t data;
- * };
- *
- * The system call to wait for I/O events is epoll_wait(2). It populates an
- * array of epoll_event structures that are passed to the call. The data
- * member of the epoll_event structure contains the same data as was set
- * when the file descriptor was registered to epoll via epoll_ctl(2). In
- * this implementation we set data.fd to be the file descriptor that we
- * register. That way, we have the file descriptor available when we
- * process the events.
- */
-
-class EPollArrayWrapper {
- // EPOLL_EVENTS
- private static final int EPOLLIN = 0x001;
-
- // opcodes
- private static final int EPOLL_CTL_ADD = 1;
- private static final int EPOLL_CTL_DEL = 2;
- private static final int EPOLL_CTL_MOD = 3;
-
- // Miscellaneous constants
- private static final int SIZE_EPOLLEVENT = sizeofEPollEvent();
- private static final int EVENT_OFFSET = 0;
- private static final int DATA_OFFSET = offsetofData();
- private static final int FD_OFFSET = DATA_OFFSET;
- private static final int OPEN_MAX = IOUtil.fdLimit();
- private static final int NUM_EPOLLEVENTS = Math.min(OPEN_MAX, 8192);
-
- // Special value to indicate that an update should be ignored
- private static final byte KILLED = (byte)-1;
-
- // Initial size of arrays for fd registration changes
- private static final int INITIAL_PENDING_UPDATE_SIZE = 64;
-
- // maximum size of updatesLow
- private static final int MAX_UPDATE_ARRAY_SIZE = AccessController.doPrivileged(
- new GetIntegerAction("sun.nio.ch.maxUpdateArraySize", Math.min(OPEN_MAX, 64*1024)));
-
- // The fd of the epoll driver
- private final int epfd;
-
- // The epoll_event array for results from epoll_wait
- private final AllocatedNativeObject pollArray;
-
- // Base address of the epoll_event array
- private final long pollArrayAddress;
-
- // The fd of the interrupt line going out
- private final int outgoingInterruptFD;
-
- // Number of updated pollfd entries
- private int updated;
-
- // object to synchronize fd registration changes
- private final Object updateLock = new Object();
-
- // number of file descriptors with registration changes pending
- private int updateCount;
-
- // file descriptors with registration changes pending
- private int[] updateDescriptors = new int[INITIAL_PENDING_UPDATE_SIZE];
-
- // events for file descriptors with registration changes pending, indexed
- // by file descriptor and stored as bytes for efficiency reasons. For
- // file descriptors higher than MAX_UPDATE_ARRAY_SIZE (unlimited case at
- // least) then the update is stored in a map.
- private final byte[] eventsLow = new byte[MAX_UPDATE_ARRAY_SIZE];
- private final Map<Integer,Byte> eventsHigh = new HashMap<>();
-
- // Used by release and updateRegistrations to track whether a file
- // descriptor is registered with epoll.
- private final BitSet registered = new BitSet();
-
-
- EPollArrayWrapper(int fd0, int fd1) throws IOException {
- // creates the epoll file descriptor
- epfd = epollCreate();
-
- // the epoll_event array passed to epoll_wait
- int allocationSize = NUM_EPOLLEVENTS * SIZE_EPOLLEVENT;
- pollArray = new AllocatedNativeObject(allocationSize, true);
- pollArrayAddress = pollArray.address();
-
- outgoingInterruptFD = fd1;
- epollCtl(epfd, EPOLL_CTL_ADD, fd0, EPOLLIN);
- }
-
- void putEventOps(int i, int event) {
- int offset = SIZE_EPOLLEVENT * i + EVENT_OFFSET;
- pollArray.putInt(offset, event);
- }
-
- void putDescriptor(int i, int fd) {
- int offset = SIZE_EPOLLEVENT * i + FD_OFFSET;
- pollArray.putInt(offset, fd);
- }
-
- int getEventOps(int i) {
- int offset = SIZE_EPOLLEVENT * i + EVENT_OFFSET;
- return pollArray.getInt(offset);
- }
-
- int getDescriptor(int i) {
- int offset = SIZE_EPOLLEVENT * i + FD_OFFSET;
- return pollArray.getInt(offset);
- }
-
- /**
- * Returns {@code true} if updates for the given key (file
- * descriptor) are killed.
- */
- private boolean isEventsHighKilled(Integer key) {
- assert key >= MAX_UPDATE_ARRAY_SIZE;
- Byte value = eventsHigh.get(key);
- return (value != null && value == KILLED);
- }
-
- /**
- * Sets the pending update events for the given file descriptor. This
- * method has no effect if the update events is already set to KILLED,
- * unless {@code force} is {@code true}.
- */
- private void setUpdateEvents(int fd, byte events, boolean force) {
- if (fd < MAX_UPDATE_ARRAY_SIZE) {
- if ((eventsLow[fd] != KILLED) || force) {
- eventsLow[fd] = events;
- }
- } else {
- Integer key = Integer.valueOf(fd);
- if (!isEventsHighKilled(key) || force) {
- eventsHigh.put(key, Byte.valueOf(events));
- }
- }
- }
-
- /**
- * Returns the pending update events for the given file descriptor.
- */
- private byte getUpdateEvents(int fd) {
- if (fd < MAX_UPDATE_ARRAY_SIZE) {
- return eventsLow[fd];
- } else {
- Byte result = eventsHigh.get(Integer.valueOf(fd));
- // result should never be null
- return result.byteValue();
- }
- }
-
- /**
- * Update the events for a given file descriptor
- */
- void setInterest(int fd, int mask) {
- synchronized (updateLock) {
- // record the file descriptor and events
- int oldCapacity = updateDescriptors.length;
- if (updateCount == oldCapacity) {
- int newCapacity = oldCapacity + INITIAL_PENDING_UPDATE_SIZE;
- int[] newDescriptors = new int[newCapacity];
- System.arraycopy(updateDescriptors, 0, newDescriptors, 0, oldCapacity);
- updateDescriptors = newDescriptors;
- }
- updateDescriptors[updateCount++] = fd;
-
- // events are stored as bytes for efficiency reasons
- byte b = (byte)mask;
- assert (b == mask) && (b != KILLED);
- setUpdateEvents(fd, b, false);
- }
- }
-
- /**
- * Add a file descriptor
- */
- void add(int fd) {
- // force the initial update events to 0 as it may be KILLED by a
- // previous registration.
- synchronized (updateLock) {
- assert !registered.get(fd);
- setUpdateEvents(fd, (byte)0, true);
- }
- }
-
- /**
- * Remove a file descriptor
- */
- void remove(int fd) {
- synchronized (updateLock) {
- // kill pending and future update for this file descriptor
- setUpdateEvents(fd, KILLED, false);
-
- // remove from epoll
- if (registered.get(fd)) {
- epollCtl(epfd, EPOLL_CTL_DEL, fd, 0);
- registered.clear(fd);
- }
- }
- }
-
- /**
- * Close epoll file descriptor and free poll array
- */
- void close() throws IOException {
- FileDispatcherImpl.closeIntFD(epfd);
- pollArray.free();
- }
-
- int poll(long timeout) throws IOException {
- updateRegistrations();
- return epollWait(pollArrayAddress, NUM_EPOLLEVENTS, timeout, epfd);
- }
-
- /**
- * Update the pending registrations.
- */
- private void updateRegistrations() {
- synchronized (updateLock) {
- int j = 0;
- while (j < updateCount) {
- int fd = updateDescriptors[j];
- short events = getUpdateEvents(fd);
- boolean isRegistered = registered.get(fd);
- int opcode = 0;
-
- if (events != KILLED) {
- if (isRegistered) {
- opcode = (events != 0) ? EPOLL_CTL_MOD : EPOLL_CTL_DEL;
- } else {
- opcode = (events != 0) ? EPOLL_CTL_ADD : 0;
- }
- if (opcode != 0) {
- epollCtl(epfd, opcode, fd, events);
- if (opcode == EPOLL_CTL_ADD) {
- registered.set(fd);
- } else if (opcode == EPOLL_CTL_DEL) {
- registered.clear(fd);
- }
- }
- }
- j++;
- }
- updateCount = 0;
- }
- }
-
- public void interrupt() {
- interrupt(outgoingInterruptFD);
- }
-
- static {
- IOUtil.load();
- init();
- }
-
- private native int epollCreate();
- private native void epollCtl(int epfd, int opcode, int fd, int events);
- private native int epollWait(long pollAddress, int numfds, long timeout,
- int epfd) throws IOException;
- private static native int sizeofEPollEvent();
- private static native int offsetofData();
- private static native void interrupt(int fd);
- private static native void init();
-}