| /* |
| * Copyright (c) 2002, 2019, 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.lang.annotation.Native; |
| |
| // Constants for reporting I/O status |
| |
| public final class IOStatus { |
| |
| private IOStatus() { } |
| |
| @Native public static final int EOF = -1; // End of file |
| @Native public static final int UNAVAILABLE = -2; // Nothing available (non-blocking) |
| @Native public static final int INTERRUPTED = -3; // System call interrupted |
| @Native public static final int UNSUPPORTED = -4; // Operation not supported |
| @Native public static final int THROWN = -5; // Exception thrown in JNI code |
| @Native public static final int UNSUPPORTED_CASE = -6; // This case not supported |
| |
| // The following two methods are for use in try/finally blocks where a |
| // status value needs to be normalized before being returned to the invoker |
| // but also checked for illegal negative values before the return |
| // completes, like so: |
| // |
| // int n = 0; |
| // try { |
| // begin(); |
| // n = op(fd, buf, ...); |
| // return IOStatus.normalize(n); // Converts UNAVAILABLE to zero |
| // } finally { |
| // end(n > 0); |
| // assert IOStatus.check(n); // Checks other negative values |
| // } |
| // |
| |
| public static int normalize(int n) { |
| if (n == UNAVAILABLE) |
| return 0; |
| return n; |
| } |
| |
| public static boolean check(int n) { |
| return (n >= UNAVAILABLE); |
| } |
| |
| public static long normalize(long n) { |
| if (n == UNAVAILABLE) |
| return 0; |
| return n; |
| } |
| |
| public static boolean check(long n) { |
| return (n >= UNAVAILABLE); |
| } |
| |
| // Return true iff n is not one of the IOStatus values |
| public static boolean checkAll(long n) { |
| return ((n > EOF) || (n < UNSUPPORTED_CASE)); |
| } |
| |
| /** |
| * Returns true if the error code is UNAVAILABLE or INTERRUPTED, the |
| * error codes to indicate that an I/O operation can be retried. |
| */ |
| static boolean okayToRetry(long n) { |
| return (n == IOStatus.UNAVAILABLE) || (n == IOStatus.INTERRUPTED); |
| } |
| |
| } |