1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
/*
* Copyright (c) 2002, 2013, 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));
}
}
|
