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 // Android-changed: Fix poll.h include location
39 // #include <sys/poll.h>
40 #include <poll.h>
41
42 #include <AsynchronousCloseMonitor.h>
43
44 extern "C" {
45
46 /*
47 * Signal to unblock thread
48 */
49 // Android-changed: Bionic (and AsynchronousCloseMonitor) expects libcore to use
50 // __SIGRTMIN + 2, not __SIGRTMAX - 2
51 static int sigWakeup = (__SIGRTMIN + 2);
52
53 /*
54 * Close or dup2 a file descriptor ensuring that all threads blocked on
55 * the file descriptor are notified via a wakeup signal.
56 *
57 * fd1 < 0 => close(fd2)
58 * fd1 >= 0 => dup2(fd1, fd2)
59 *
60 * Returns -1 with errno set if operation fails.
61 */
closefd(int fd1,int fd2)62 static int closefd(int fd1, int fd2) {
63 int rv, orig_errno;
64
65 AsynchronousCloseMonitor::signalBlockedThreads(fd2);
66
67 /*
68 * And close/dup the file descriptor
69 * (restart if interrupted by signal)
70 */
71 do {
72 if (fd1 < 0) {
73 rv = close(fd2);
74 } else {
75 rv = dup2(fd1, fd2);
76 }
77 } while (rv == -1 && errno == EINTR);
78 return rv;
79 }
80
81 /*
82 * Wrapper for dup2 - same semantics as dup2 system call except
83 * that any threads blocked in an I/O system call on fd2 will be
84 * preempted and return -1/EBADF;
85 */
NET_Dup2(int fd,int fd2)86 int NET_Dup2(int fd, int fd2) {
87 if (fd < 0) {
88 errno = EBADF;
89 return -1;
90 }
91 return closefd(fd, fd2);
92 }
93
94 /*
95 * Wrapper for close - same semantics as close system call
96 * except that any threads blocked in an I/O on fd will be
97 * preempted and the I/O system call will return -1/EBADF.
98 */
NET_SocketClose(int fd)99 int NET_SocketClose(int fd) {
100 return closefd(-1, fd);
101 }
102
103 /************** Basic I/O operations here ***************/
104
105 /*
106 * Macro to perform a blocking IO operation. Restarts
107 * automatically if interrupted by signal (other than
108 * our wakeup signal)
109 */
110 #define BLOCKING_IO_RETURN_INT(FD, FUNC) { \
111 int ret; \
112 int _syscallErrno; \
113 do { \
114 bool _wasSignaled; \
115 { \
116 AsynchronousCloseMonitor _monitor(FD); \
117 ret = FUNC; \
118 _syscallErrno = errno; \
119 _wasSignaled = _monitor.wasSignaled(); \
120 } \
121 errno = _wasSignaled ? EBADF : _syscallErrno; \
122 } while (ret == -1 && errno == EINTR); \
123 return ret; \
124 }
125
126
NET_Read(int s,void * buf,size_t len)127 int NET_Read(int s, void* buf, size_t len) {
128 BLOCKING_IO_RETURN_INT( s, recv(s, buf, len, 0) );
129 }
130
NET_ReadV(int s,const struct iovec * vector,int count)131 int NET_ReadV(int s, const struct iovec * vector, int count) {
132 BLOCKING_IO_RETURN_INT( s, readv(s, vector, count) );
133 }
134
NET_RecvFrom(int s,void * buf,int len,unsigned int flags,struct sockaddr * from,int * fromlen)135 int NET_RecvFrom(int s, void *buf, int len, unsigned int flags,
136 struct sockaddr *from, int *fromlen) {
137 socklen_t socklen = *fromlen;
138 BLOCKING_IO_RETURN_INT( s, recvfrom(s, buf, len, flags, from, &socklen) );
139 *fromlen = socklen;
140 }
141
NET_Send(int s,void * msg,int len,unsigned int flags)142 int NET_Send(int s, void *msg, int len, unsigned int flags) {
143 BLOCKING_IO_RETURN_INT( s, send(s, msg, len, flags) );
144 }
145
NET_WriteV(int s,const struct iovec * vector,int count)146 int NET_WriteV(int s, const struct iovec * vector, int count) {
147 BLOCKING_IO_RETURN_INT( s, writev(s, vector, count) );
148 }
149
NET_SendTo(int s,const void * msg,int len,unsigned int flags,const struct sockaddr * to,int tolen)150 int NET_SendTo(int s, const void *msg, int len, unsigned int
151 flags, const struct sockaddr *to, int tolen) {
152 BLOCKING_IO_RETURN_INT( s, sendto(s, msg, len, flags, to, tolen) );
153 }
154
NET_Accept(int s,struct sockaddr * addr,int * addrlen)155 int NET_Accept(int s, struct sockaddr *addr, int *addrlen) {
156 socklen_t socklen = *addrlen;
157 BLOCKING_IO_RETURN_INT( s, accept(s, addr, &socklen) );
158 *addrlen = socklen;
159 }
160
NET_Connect(int s,struct sockaddr * addr,int addrlen)161 int NET_Connect(int s, struct sockaddr *addr, int addrlen) {
162 BLOCKING_IO_RETURN_INT( s, connect(s, addr, addrlen) );
163 }
164
165 #ifndef USE_SELECT
NET_Poll(struct pollfd * ufds,unsigned int nfds,int timeout)166 int NET_Poll(struct pollfd *ufds, unsigned int nfds, int timeout) {
167 BLOCKING_IO_RETURN_INT( ufds[0].fd, poll(ufds, nfds, timeout) );
168 }
169 #else
NET_Select(int s,fd_set * readfds,fd_set * writefds,fd_set * exceptfds,struct timeval * timeout)170 int NET_Select(int s, fd_set *readfds, fd_set *writefds,
171 fd_set *exceptfds, struct timeval *timeout) {
172 BLOCKING_IO_RETURN_INT( s-1,
173 select(s, readfds, writefds, exceptfds, timeout) );
174 }
175 #endif
176
177 /*
178 * Wrapper for poll(s, timeout).
179 * Auto restarts with adjusted timeout if interrupted by
180 * signal other than our wakeup signal.
181 *
182 * If s < 0, exits early rather than delegating to poll().
183 * TODO: Investigate whether it'd be better to handle this
184 * case at the caller so that this function is never called
185 * for s < 0.
186 */
NET_Timeout(int s,long timeout)187 int NET_Timeout(int s, long timeout) {
188 long prevtime = 0, newtime;
189 struct timeval t;
190
191 /*
192 * b/27763633
193 * Avoid blocking calls to poll() for invalid sockets, e.g. when
194 * called from PlainSocketImpl_socketAccept with fd == -1.
195 */
196 if (s < 0) {
197 errno = EBADF;
198 return -1;
199 }
200
201 /*
202 * Pick up current time as may need to adjust timeout
203 */
204 if (timeout > 0) {
205 gettimeofday(&t, NULL);
206 prevtime = t.tv_sec * 1000 + t.tv_usec / 1000;
207 }
208
209 for(;;) {
210 struct pollfd pfd;
211 int rv;
212
213 /*
214 * Poll the fd. If interrupted by our wakeup signal
215 * errno will be set to EBADF.
216 */
217 pfd.fd = s;
218 pfd.events = POLLIN | POLLERR;
219
220 bool wasSignaled;
221 int syscallErrno;
222 {
223 AsynchronousCloseMonitor monitor(s);
224 rv = poll(&pfd, 1, timeout);
225 syscallErrno = errno;
226 wasSignaled = monitor.wasSignaled();
227 }
228 errno = wasSignaled ? EBADF : syscallErrno;
229
230 /*
231 * If interrupted then adjust timeout. If timeout
232 * has expired return 0 (indicating timeout expired).
233 */
234 if (rv < 0 && errno == EINTR) {
235 if (timeout > 0) {
236 gettimeofday(&t, NULL);
237 newtime = t.tv_sec * 1000 + t.tv_usec / 1000;
238 timeout -= newtime - prevtime;
239 if (timeout <= 0) {
240 return 0;
241 }
242 prevtime = newtime;
243 }
244 } else {
245 return rv;
246 }
247
248 }
249 }
250
251 }
252