1 /* 2 * Copyright (c) 2017, 2023, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package sun.nio.ch; 26 27 import java.io.IOException; 28 import static sun.nio.ch.EPoll.*; 29 30 /** 31 * Poller implementation based on the epoll facility. 32 */ 33 34 class EPollPoller extends Poller { 35 private static final int ENOENT = 2; 36 37 private final int epfd; 38 private final int event; 39 private final int maxEvents; 40 private final long address; 41 42 EPollPoller(boolean subPoller, boolean read) throws IOException { 43 this.epfd = EPoll.create(); 44 this.event = (read) ? EPOLLIN : EPOLLOUT; 45 this.maxEvents = (subPoller) ? 64 : 512; 46 this.address = EPoll.allocatePollArray(maxEvents); 47 } 48 49 @Override 50 int fdVal() { 51 return epfd; 52 } 53 54 @Override 55 void implRegister(int fdVal) throws IOException { 56 // re-arm 57 int err = EPoll.ctl(epfd, EPOLL_CTL_MOD, fdVal, (event | EPOLLONESHOT)); 58 if (err == ENOENT) 59 err = EPoll.ctl(epfd, EPOLL_CTL_ADD, fdVal, (event | EPOLLONESHOT)); 60 if (err != 0) 61 throw new IOException("epoll_ctl failed: " + err); 62 } 63 64 @Override 65 void implDeregister(int fdVal, boolean polled) { 66 // event is disabled if already polled 67 if (!polled) { 68 EPoll.ctl(epfd, EPOLL_CTL_DEL, fdVal, 0); 69 } 70 } 71 72 @Override 73 int poll(int timeout) throws IOException { 74 int n = EPoll.wait(epfd, address, maxEvents, timeout); 75 int i = 0; 76 while (i < n) { 77 long eventAddress = EPoll.getEvent(address, i); 78 int fdVal = EPoll.getDescriptor(eventAddress); 79 polled(fdVal); 80 i++; 81 } 82 return n; 83 } 84 } 85