1 /* 2 * Copyright (c) 2002, 2013, 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 26 package sun.nio.ch; 27 28 import java.lang.annotation.Native; 29 30 // Constants for reporting I/O status 31 32 public final class IOStatus { 33 34 private IOStatus() { } 35 36 @Native public static final int EOF = -1; // End of file 37 @Native public static final int UNAVAILABLE = -2; // Nothing available (non-blocking) 38 @Native public static final int INTERRUPTED = -3; // System call interrupted 39 @Native public static final int UNSUPPORTED = -4; // Operation not supported 40 @Native public static final int THROWN = -5; // Exception thrown in JNI code 41 @Native public static final int UNSUPPORTED_CASE = -6; // This case not supported 42 43 // The following two methods are for use in try/finally blocks where a 44 // status value needs to be normalized before being returned to the invoker 45 // but also checked for illegal negative values before the return 46 // completes, like so: 47 // 48 // int n = 0; 49 // try { 50 // begin(); 51 // n = op(fd, buf, ...); 52 // return IOStatus.normalize(n); // Converts UNAVAILABLE to zero 53 // } finally { 54 // end(n > 0); 55 // assert IOStatus.check(n); // Checks other negative values 56 // } 57 // 58 59 public static int normalize(int n) { 60 if (n == UNAVAILABLE) 61 return 0; 62 return n; 63 } 64 65 public static boolean check(int n) { 66 return (n >= UNAVAILABLE); 67 } 68 69 public static long normalize(long n) { 70 if (n == UNAVAILABLE) 71 return 0; 72 return n; 73 } 74 75 public static boolean check(long n) { 76 return (n >= UNAVAILABLE); 77 } 78 79 // Return true iff n is not one of the IOStatus values 80 public static boolean checkAll(long n) { 81 return ((n > EOF) || (n < UNSUPPORTED_CASE)); 82 } 83 84 } 85
