1 /* 2 * Copyright (c) 2002, 2003, 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 29 // Constants for reporting I/O status 30 31 final class IOStatus { 32 IOStatus()33 private IOStatus() { } 34 35 static final int EOF = -1; // End of file 36 static final int UNAVAILABLE = -2; // Nothing available (non-blocking) 37 static final int INTERRUPTED = -3; // System call interrupted 38 static final int UNSUPPORTED = -4; // Operation not supported 39 static final int THROWN = -5; // Exception thrown in JNI code 40 static final int UNSUPPORTED_CASE = -6; // This case not supported 41 42 // The following two methods are for use in try/finally blocks where a 43 // status value needs to be normalized before being returned to the invoker 44 // but also checked for illegal negative values before the return 45 // completes, like so: 46 // 47 // int n = 0; 48 // try { 49 // begin(); 50 // n = op(fd, buf, ...); 51 // return IOStatus.normalize(n); // Converts UNAVAILABLE to zero 52 // } finally { 53 // end(n > 0); 54 // assert IOStatus.check(n); // Checks other negative values 55 // } 56 // 57 normalize(int n)58 static int normalize(int n) { 59 if (n == UNAVAILABLE) 60 return 0; 61 return n; 62 } 63 check(int n)64 static boolean check(int n) { 65 return (n >= UNAVAILABLE); 66 } 67 normalize(long n)68 static long normalize(long n) { 69 if (n == UNAVAILABLE) 70 return 0; 71 return n; 72 } 73 check(long n)74 static boolean check(long n) { 75 return (n >= UNAVAILABLE); 76 } 77 78 // Return true iff n is not one of the IOStatus values checkAll(long n)79 static boolean checkAll(long n) { 80 return ((n > EOF) || (n < UNSUPPORTED_CASE)); 81 } 82 83 } 84