93 lines
3.3 KiB
Java
93 lines
3.3 KiB
Java
/*
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* Copyright (c) 2002, 2019, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package sun.nio.ch;
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import java.lang.annotation.Native;
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// Constants for reporting I/O status
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public final class IOStatus {
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private IOStatus() { }
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@Native public static final int EOF = -1; // End of file
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@Native public static final int UNAVAILABLE = -2; // Nothing available (non-blocking)
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@Native public static final int INTERRUPTED = -3; // System call interrupted
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@Native public static final int UNSUPPORTED = -4; // Operation not supported
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@Native public static final int THROWN = -5; // Exception thrown in JNI code
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@Native public static final int UNSUPPORTED_CASE = -6; // This case not supported
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// The following two methods are for use in try/finally blocks where a
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// status value needs to be normalized before being returned to the invoker
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// but also checked for illegal negative values before the return
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// completes, like so:
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//
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// int n = 0;
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// try {
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// begin();
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// n = op(fd, buf, ...);
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// return IOStatus.normalize(n); // Converts UNAVAILABLE to zero
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// } finally {
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// end(n > 0);
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// assert IOStatus.check(n); // Checks other negative values
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// }
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//
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public static int normalize(int n) {
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if (n == UNAVAILABLE)
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return 0;
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return n;
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}
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public static boolean check(int n) {
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return (n >= UNAVAILABLE);
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}
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public static long normalize(long n) {
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if (n == UNAVAILABLE)
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return 0;
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return n;
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}
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public static boolean check(long n) {
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return (n >= UNAVAILABLE);
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}
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// Return true iff n is not one of the IOStatus values
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public static boolean checkAll(long n) {
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return ((n > EOF) || (n < UNSUPPORTED_CASE));
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}
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/**
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* Returns true if the error code is UNAVAILABLE or INTERRUPTED, the
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* error codes to indicate that an I/O operation can be retried.
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*/
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static boolean okayToRetry(long n) {
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return (n == IOStatus.UNAVAILABLE) || (n == IOStatus.INTERRUPTED);
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}
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}
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