1 /*
2 * Copyright 2001-2005 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 #include "jni.h"
27 #include "jni_util.h"
28 #include "jvm.h"
29 #include "jlong.h"
30 #include "sun_nio_ch_DevPollArrayWrapper.h"
31 #include "java_lang_Integer.h"
32 #include <sys/poll.h>
33 #include <sys/resource.h>
34 #include <unistd.h>
35 #include <sys/time.h>
36
37 #ifdef __cplusplus
38 extern "C" {
39 #endif
40
41 typedef uint32_t caddr32_t;
42
43 /* /dev/poll ioctl */
44 #define DPIOC (0xD0 << 8)
45 #define DP_POLL (DPIOC | 1) /* poll on fds in cached in /dev/poll */
46 #define DP_ISPOLLED (DPIOC | 2) /* is this fd cached in /dev/poll */
47 #define DEVPOLLSIZE 1000 /* /dev/poll table size increment */
48 #define POLLREMOVE 0x0800 /* Removes fd from monitored set */
49
50 /*
51 * /dev/poll DP_POLL ioctl format
52 */
53 typedef struct dvpoll {
54 pollfd_t *dp_fds; /* pollfd array */
55 nfds_t dp_nfds; /* num of pollfd's in dp_fds[] */
56 int dp_timeout; /* time out in millisec */
57 } dvpoll_t;
58
59 typedef struct dvpoll32 {
60 caddr32_t dp_fds; /* pollfd array */
61 uint32_t dp_nfds; /* num of pollfd's in dp_fds[] */
62 int32_t dp_timeout; /* time out in millisec */
63 } dvpoll32_t;
64
65 #ifdef __cplusplus
66 }
67 #endif
68
69 #define RESTARTABLE(_cmd, _result) do { \
70 do { \
71 _result = _cmd; \
72 } while((_result == -1) && (errno == EINTR)); \
73 } while(0)
74
75 static int
76 idevpoll(jint wfd, int dpctl, struct dvpoll a)
77 {
78 jlong start, now;
79 int remaining = a.dp_timeout;
80 struct timeval t;
81 int diff;
82
83 gettimeofday(&t, NULL);
84 start = t.tv_sec * 1000 + t.tv_usec / 1000;
85
86 for (;;) {
87 /* poll(7d) ioctl does not return remaining count */
88 int res = ioctl(wfd, dpctl, &a);
89 if (res < 0 && errno == EINTR) {
90 if (remaining >= 0) {
91 gettimeofday(&t, NULL);
92 now = t.tv_sec * 1000 + t.tv_usec / 1000;
93 diff = now - start;
94 remaining -= diff;
95 if (diff < 0 || remaining <= 0) {
96 return 0;
97 }
98 start = now;
99 }
100 } else {
101 return res;
102 }
103 }
104 }
105
106 JNIEXPORT jint JNICALL
107 Java_sun_nio_ch_DevPollArrayWrapper_init(JNIEnv *env, jobject this)
108 {
109 int wfd = open("/dev/poll", O_RDWR);
110 if (wfd < 0) {
111 JNU_ThrowIOExceptionWithLastError(env, "Error opening driver");
112 return -1;
113 }
114 return wfd;
115 }
116
117 JNIEXPORT void JNICALL
118 Java_sun_nio_ch_DevPollArrayWrapper_register(JNIEnv *env, jobject this,
119 jint wfd, jint fd, jint mask)
120 {
121 struct pollfd a[2];
122 unsigned char *pollBytes = (unsigned char *)&a[0];
123 unsigned char *pollEnd = pollBytes + sizeof(struct pollfd) * 2;
124
125 /* We clear it first, otherwise any entries between poll invocations
126 get OR'd together */
127 a[0].fd = fd;
128 a[0].events = POLLREMOVE;
129 a[0].revents = 0;
130
131 a[1].fd = fd;
132 a[1].events = mask;
133 a[1].revents = 0;
134
135 while (pollBytes < pollEnd) {
136 int bytesWritten = write(wfd, pollBytes, (int)(pollEnd - pollBytes));
137 if (bytesWritten < 0) {
138 JNU_ThrowIOExceptionWithLastError(env, "Error writing pollfds");
139 return;
140 }
141 pollBytes += bytesWritten;
142 }
143 }
144
145 JNIEXPORT void JNICALL
146 Java_sun_nio_ch_DevPollArrayWrapper_registerMultiple(JNIEnv *env, jobject this,
147 jint wfd, jlong address,
148 jint len)
149 {
150 unsigned char *pollBytes = (unsigned char *)jlong_to_ptr(address);
151 unsigned char *pollEnd = pollBytes + sizeof(struct pollfd) * len;
152 while (pollBytes < pollEnd) {
153 int bytesWritten = write(wfd, pollBytes, (int)(pollEnd - pollBytes));
154 if (bytesWritten < 0) {
155 JNU_ThrowIOExceptionWithLastError(env, "Error writing pollfds");
156 return;
157 }
158 pollBytes += bytesWritten;
159 }
160 }
161
162 JNIEXPORT jint JNICALL
163 Java_sun_nio_ch_DevPollArrayWrapper_poll0(JNIEnv *env, jobject this,
164 jlong address, jint numfds,
165 jlong timeout, jint wfd)
166 {
167 struct dvpoll a;
168 void *pfd = (void *) jlong_to_ptr(address);
169 int result = 0;
170
171 a.dp_fds = pfd;
172 a.dp_nfds = numfds;
173 a.dp_timeout = (int)timeout;
174
175 if (timeout <= 0) { /* Indefinite or no wait */
176 RESTARTABLE (ioctl(wfd, DP_POLL, &a), result);
177 } else { /* Bounded wait; bounded restarts */
178 result = idevpoll(wfd, DP_POLL, a);
179 }
180
181 if (result < 0) {
182 JNU_ThrowIOExceptionWithLastError(env, "Error reading driver");
183 return -1;
184 }
185 return result;
186 }
187
188 JNIEXPORT jint JNICALL
189 Java_sun_nio_ch_DevPollArrayWrapper_fdLimit(JNIEnv *env, jclass this)
190 {
191 struct rlimit rlp;
192 if (getrlimit(RLIMIT_NOFILE, &rlp) < 0) {
193 JNU_ThrowIOExceptionWithLastError(env,
194 "getrlimit failed");
195 }
196 if (rlp.rlim_max < 0 || rlp.rlim_max > java_lang_Integer_MAX_VALUE) {
197 return java_lang_Integer_MAX_VALUE;
198 } else {
199 return (jint)rlp.rlim_max;
200 }
201 }
202
203 JNIEXPORT void JNICALL
204 Java_sun_nio_ch_DevPollArrayWrapper_interrupt(JNIEnv *env, jclass this, jint fd)
205 {
206 int fakebuf[1];
207 fakebuf[0] = 1;
208 if (write(fd, fakebuf, 1) < 0) {
209 JNU_ThrowIOExceptionWithLastError(env,
210 "Write to interrupt fd failed");
211 }
212 }