rev 12972 : 8140606: Update library code to use internal Unsafe
Reviewed-by: duke
1 /*
2 * Copyright (c) 2012, 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.io.IOException;
29 import sun.misc.Unsafe;
30
31 /**
32 * Provides access to the BSD kqueue facility.
33 */
34
35 class KQueue {
36 private KQueue() { }
37
38 private static final Unsafe unsafe = Unsafe.getUnsafe();
39
40 /**
41 * struct kevent {
42 * uintptr_t ident; // identifier for this event, usually the fd
43 * int16_t filter; // filter for event
44 * uint16_t flags; // general flags
45 * uint32_t fflags; // filter-specific flags
46 * intptr_t data; // filter-specific data
47 * void *udata; // opaque user data identifier
48 * };
49 */
50 private static final int SIZEOF_KQUEUEEVENT = keventSize();
51 private static final int OFFSET_IDENT = identOffset();
52 private static final int OFFSET_FILTER = filterOffset();
53 private static final int OFFSET_FLAGS = flagsOffset();
54
55 // filters
56 static final int EVFILT_READ = -1;
57 static final int EVFILT_WRITE = -2;
58
59 // flags
60 static final int EV_ADD = 0x0001;
61 static final int EV_ONESHOT = 0x0010;
62 static final int EV_CLEAR = 0x0020;
63
64 /**
65 * Allocates a poll array to handle up to {@code count} events.
66 */
67 static long allocatePollArray(int count) {
68 return unsafe.allocateMemory(count * SIZEOF_KQUEUEEVENT);
69 }
70
71 /**
72 * Free a poll array
73 */
74 static void freePollArray(long address) {
75 unsafe.freeMemory(address);
76 }
77
78 /**
79 * Returns kevent[i].
80 */
81 static long getEvent(long address, int i) {
82 return address + (SIZEOF_KQUEUEEVENT*i);
83 }
84
85 /**
86 * Returns the file descriptor from a kevent (assuming to be in ident field)
87 */
88 static int getDescriptor(long address) {
89 return unsafe.getInt(address + OFFSET_IDENT);
90 }
91
92 static int getFilter(long address) {
93 return unsafe.getShort(address + OFFSET_FILTER);
94 }
95
96 static int getFlags(long address) {
97 return unsafe.getShort(address + OFFSET_FLAGS);
98 }
99
100 // -- Native methods --
101
102 private static native int keventSize();
103
104 private static native int identOffset();
105
106 private static native int filterOffset();
107
108 private static native int flagsOffset();
109
110 static native int kqueue() throws IOException;
111
112 static native int keventRegister(int kqpfd, int fd, int filter, int flags);
113
114 static native int keventPoll(int kqpfd, long pollAddress, int nevents)
115 throws IOException;
116
117 static {
118 IOUtil.load();
119 }
120 }
--- EOF ---