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 */ 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 */ 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 */ 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 } 122 123 124 int NET_Read(int s, void* buf, size_t len) { 125 BLOCKING_IO_RETURN_INT( s, recv(s, buf, len, 0) ); 126 } 127 128 int NET_ReadV(int s, const struct iovec * vector, int count) { 129 BLOCKING_IO_RETURN_INT( s, readv(s, vector, count) ); 130 } 131 132 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 } 138 139 int NET_Send(int s, void *msg, int len, unsigned int flags) { 140 BLOCKING_IO_RETURN_INT( s, send(s, msg, len, flags) ); 141 } 142 143 int NET_WriteV(int s, const struct iovec * vector, int count) { 144 BLOCKING_IO_RETURN_INT( s, writev(s, vector, count) ); 145 } 146 147 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 } 151 152 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 } 157 158 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 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 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 */ 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
