1 /*
2 * Copyright (c) 2001, 2011, 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 <stdio.h>
27 #include <stdlib.h>
28 #include <signal.h>
29 #include <pthread.h>
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <sys/time.h>
33 #include <sys/resource.h>
34 #include <sys/uio.h>
35 #include <unistd.h>
36 #include <errno.h>
37
38 #include <sys/poll.h>
39
40
41 #include "AsynchronousCloseMonitor.h"
42
43 extern "C" {
44
45 /*
46 * Signal to unblock thread
47 */
48 static int sigWakeup = (__SIGRTMAX - 2);
49
50 /*
51 * Close or dup2 a file descriptor ensuring that all threads blocked on
52 * the file descriptor are notified via a wakeup signal.
53 *
54 * fd1 < 0 => close(fd2)
55 * fd1 >= 0 => dup2(fd1, fd2)
56 *
57 * Returns -1 with errno set if operation fails.
58 */
closefd(int fd1,int fd2)59 static int closefd(int fd1, int fd2) {
60 int rv, orig_errno;
61
62 AsynchronousCloseMonitor::signalBlockedThreads(fd2);
63
64 /*
65 * And close/dup the file descriptor
66 * (restart if interrupted by signal)
67 */
68 do {
69 if (fd1 < 0) {
70 rv = close(fd2);
71 } else {
72 rv = dup2(fd1, fd2);
73 }
74 } while (rv == -1 && errno == EINTR);
75 return rv;
76 }
77
78 /*
79 * Wrapper for dup2 - same semantics as dup2 system call except
80 * that any threads blocked in an I/O system call on fd2 will be
81 * preempted and return -1/EBADF;
82 */
NET_Dup2(int fd,int fd2)83 int NET_Dup2(int fd, int fd2) {
84 if (fd < 0) {
85 errno = EBADF;
86 return -1;
87 }
88 return closefd(fd, fd2);
89 }
90
91 /*
92 * Wrapper for close - same semantics as close system call
93 * except that any threads blocked in an I/O on fd will be
94 * preempted and the I/O system call will return -1/EBADF.
95 */
NET_SocketClose(int fd)96 int NET_SocketClose(int fd) {
97 return closefd(-1, fd);
98 }
99
100 /************** Basic I/O operations here ***************/
101
102 /*
103 * Macro to perform a blocking IO operation. Restarts
104 * automatically if interrupted by signal (other than
105 * our wakeup signal)
106 */
107 #define BLOCKING_IO_RETURN_INT(FD, FUNC) { \
108 int ret; \
109 int _syscallErrno; \
110 do { \
111 bool _wasSignaled; \
112 { \
113 AsynchronousCloseMonitor _monitor(FD); \
114 ret = FUNC; \
115 _syscallErrno = errno; \
116 _wasSignaled = _monitor.wasSignaled(); \
117 } \
118 errno = _wasSignaled ? EBADF : _syscallErrno; \
119 } while (ret == -1 && errno == EINTR); \
120 return ret; \
121 }
122
123
NET_Read(int s,void * buf,size_t len)124 int NET_Read(int s, void* buf, size_t len) {
125 BLOCKING_IO_RETURN_INT( s, recv(s, buf, len, 0) );
126 }
127
NET_ReadV(int s,const struct iovec * vector,int count)128 int NET_ReadV(int s, const struct iovec * vector, int count) {
129 BLOCKING_IO_RETURN_INT( s, readv(s, vector, count) );
130 }
131
NET_RecvFrom(int s,void * buf,int len,unsigned int flags,struct sockaddr * from,int * fromlen)132 int NET_RecvFrom(int s, void *buf, int len, unsigned int flags,
133 struct sockaddr *from, int *fromlen) {
134 socklen_t socklen = *fromlen;
135 BLOCKING_IO_RETURN_INT( s, recvfrom(s, buf, len, flags, from, &socklen) );
136 *fromlen = socklen;
137 }
138
NET_Send(int s,void * msg,int len,unsigned int flags)139 int NET_Send(int s, void *msg, int len, unsigned int flags) {
140 BLOCKING_IO_RETURN_INT( s, send(s, msg, len, flags) );
141 }
142
NET_WriteV(int s,const struct iovec * vector,int count)143 int NET_WriteV(int s, const struct iovec * vector, int count) {
144 BLOCKING_IO_RETURN_INT( s, writev(s, vector, count) );
145 }
146
NET_SendTo(int s,const void * msg,int len,unsigned int flags,const struct sockaddr * to,int tolen)147 int NET_SendTo(int s, const void *msg, int len, unsigned int
148 flags, const struct sockaddr *to, int tolen) {
149 BLOCKING_IO_RETURN_INT( s, sendto(s, msg, len, flags, to, tolen) );
150 }
151
NET_Accept(int s,struct sockaddr * addr,int * addrlen)152 int NET_Accept(int s, struct sockaddr *addr, int *addrlen) {
153 socklen_t socklen = *addrlen;
154 BLOCKING_IO_RETURN_INT( s, accept(s, addr, &socklen) );
155 *addrlen = socklen;
156 }
157
NET_Connect(int s,struct sockaddr * addr,int addrlen)158 int NET_Connect(int s, struct sockaddr *addr, int addrlen) {
159 BLOCKING_IO_RETURN_INT( s, connect(s, addr, addrlen) );
160 }
161
162 #ifndef USE_SELECT
NET_Poll(struct pollfd * ufds,unsigned int nfds,int timeout)163 int NET_Poll(struct pollfd *ufds, unsigned int nfds, int timeout) {
164 BLOCKING_IO_RETURN_INT( ufds[0].fd, poll(ufds, nfds, timeout) );
165 }
166 #else
NET_Select(int s,fd_set * readfds,fd_set * writefds,fd_set * exceptfds,struct timeval * timeout)167 int NET_Select(int s, fd_set *readfds, fd_set *writefds,
168 fd_set *exceptfds, struct timeval *timeout) {
169 BLOCKING_IO_RETURN_INT( s-1,
170 select(s, readfds, writefds, exceptfds, timeout) );
171 }
172 #endif
173
174 /*
175 * Wrapper for poll(s, timeout).
176 * Auto restarts with adjusted timeout if interrupted by
177 * signal other than our wakeup signal.
178 *
179 * If s < 0, exits early rather than delegating to poll().
180 * TODO: Investigate whether it'd be better to handle this
181 * case at the caller so that this function is never called
182 * for s < 0.
183 */
NET_Timeout(int s,long timeout)184 int NET_Timeout(int s, long timeout) {
185 long prevtime = 0, newtime;
186 struct timeval t;
187
188 /*
189 * b/27763633
190 * Avoid blocking calls to poll() for invalid sockets, e.g. when
191 * called from PlainSocketImpl_socketAccept with fd == -1.
192 */
193 if (s < 0) {
194 errno = EBADF;
195 return -1;
196 }
197
198 /*
199 * Pick up current time as may need to adjust timeout
200 */
201 if (timeout > 0) {
202 gettimeofday(&t, NULL);
203 prevtime = t.tv_sec * 1000 + t.tv_usec / 1000;
204 }
205
206 for(;;) {
207 struct pollfd pfd;
208 int rv;
209
210 /*
211 * Poll the fd. If interrupted by our wakeup signal
212 * errno will be set to EBADF.
213 */
214 pfd.fd = s;
215 pfd.events = POLLIN | POLLERR;
216
217 bool wasSignaled;
218 int syscallErrno;
219 {
220 AsynchronousCloseMonitor monitor(s);
221 rv = poll(&pfd, 1, timeout);
222 syscallErrno = errno;
223 wasSignaled = monitor.wasSignaled();
224 }
225 errno = wasSignaled ? EBADF : syscallErrno;
226
227 /*
228 * If interrupted then adjust timeout. If timeout
229 * has expired return 0 (indicating timeout expired).
230 */
231 if (rv < 0 && errno == EINTR) {
232 if (timeout > 0) {
233 gettimeofday(&t, NULL);
234 newtime = t.tv_sec * 1000 + t.tv_usec / 1000;
235 timeout -= newtime - prevtime;
236 if (timeout <= 0) {
237 return 0;
238 }
239 prevtime = newtime;
240 }
241 } else {
242 return rv;
243 }
244
245 }
246 }
247
248 }
249