1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.system; 18 19 import java.io.FileDescriptor; 20 import libcore.util.Objects; 21 22 /** 23 * Used as an in/out parameter to {@link Os#poll}. 24 * Corresponds to C's {@code struct pollfd} from {@code <poll.h>}. 25 */ 26 public final class StructPollfd { 27 /** The file descriptor to poll. */ 28 public FileDescriptor fd; 29 30 /** 31 * The events we're interested in. POLLIN corresponds to being in select(2)'s read fd set, 32 * POLLOUT to the write fd set. 33 */ 34 public short events; 35 36 /** The events that actually happened. */ 37 public short revents; 38 39 /** 40 * A non-standard extension that lets callers conveniently map back to the object 41 * their fd belongs to. This is used by Selector, for example, to associate each 42 * FileDescriptor with the corresponding SelectionKey. 43 */ 44 public Object userData; 45 toString()46 @Override public String toString() { 47 return Objects.toString(this); 48 } 49 } 50