1 /*
2 * Copyright (c) 2001, 2005, 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 #include "jni.h"
27 #include "jni_util.h"
28 #include "jvm.h"
29 #include "jlong.h"
30 #include <poll.h>
31 #include <unistd.h>
32 #include <sys/time.h>
33
34 #define RESTARTABLE(_cmd, _result) do { \
35 do { \
36 _result = _cmd; \
37 } while((_result == -1) && (errno == EINTR)); \
38 } while(0)
39
40 #include "JNIHelp.h"
41
42 #define NATIVE_METHOD(className, functionName, signature) \
43 { #functionName, signature, (void*)(Java_sun_nio_ch_ ## className ## _ ## functionName) }
44
45 static int
ipoll(struct pollfd fds[],unsigned int nfds,int timeout)46 ipoll(struct pollfd fds[], unsigned int nfds, int timeout)
47 {
48 jlong start, now;
49 int remaining = timeout;
50 struct timeval t;
51 int diff;
52
53 gettimeofday(&t, NULL);
54 start = t.tv_sec * 1000 + t.tv_usec / 1000;
55
56 for (;;) {
57 int res = poll(fds, nfds, remaining);
58 if (res < 0 && errno == EINTR) {
59 if (remaining >= 0) {
60 gettimeofday(&t, NULL);
61 now = t.tv_sec * 1000 + t.tv_usec / 1000;
62 diff = now - start;
63 remaining -= diff;
64 if (diff < 0 || remaining <= 0) {
65 return 0;
66 }
67 start = now;
68 }
69 } else {
70 return res;
71 }
72 }
73 }
74
75 JNIEXPORT jint JNICALL
Java_sun_nio_ch_PollArrayWrapper_poll0(JNIEnv * env,jobject this,jlong address,jint numfds,jlong timeout)76 Java_sun_nio_ch_PollArrayWrapper_poll0(JNIEnv *env, jobject this,
77 jlong address, jint numfds,
78 jlong timeout)
79 {
80 struct pollfd *a;
81 int err = 0;
82
83 a = (struct pollfd *) jlong_to_ptr(address);
84
85 if (timeout <= 0) { /* Indefinite or no wait */
86 RESTARTABLE (poll(a, numfds, timeout), err);
87 } else { /* Bounded wait; bounded restarts */
88 err = ipoll(a, numfds, timeout);
89 }
90
91 if (err < 0) {
92 JNU_ThrowIOExceptionWithLastError(env, "Poll failed");
93 }
94 return (jint)err;
95 }
96
97 JNIEXPORT void JNICALL
Java_sun_nio_ch_PollArrayWrapper_interrupt(JNIEnv * env,jobject this,jint fd)98 Java_sun_nio_ch_PollArrayWrapper_interrupt(JNIEnv *env, jobject this, jint fd)
99 {
100 int fakebuf[1];
101 fakebuf[0] = 1;
102 if (write(fd, fakebuf, 1) < 0) {
103 JNU_ThrowIOExceptionWithLastError(env,
104 "Write to interrupt fd failed");
105 }
106 }
107
108
109 static JNINativeMethod gMethods[] = {
110 NATIVE_METHOD(PollArrayWrapper, poll0, "(JIJ)I"),
111 NATIVE_METHOD(PollArrayWrapper, interrupt, "(I)V"),
112 };
113
register_sun_nio_ch_PollArrayWrapper(JNIEnv * env)114 void register_sun_nio_ch_PollArrayWrapper(JNIEnv* env) {
115 jniRegisterNativeMethods(env, "sun/nio/ch/PollArrayWrapper", gMethods, NELEM(gMethods));
116 }
117