1 /* 2 * Copyright (c) 2002, 2017, 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 /* 27 */ 28 29 /* Maximum number of sockets per select() */ 30 /* This number should be equal to WindowsSelectorImpl.MAX_SELECTABLE_FDS */ 31 /* This definition MUST precede the inclusion of winsock2.h */ 32 33 #define FD_SETSIZE 1024 34 35 #include <limits.h> 36 #include <stdlib.h> 37 #include <winsock2.h> 38 39 #include "jvm.h" 40 #include "jni.h" 41 #include "jni_util.h" 42 #include "sun_nio_ch_WindowsSelectorImpl.h" 43 #include "sun_nio_ch_PollArrayWrapper.h" 44 45 #include "nio_util.h" /* Needed for POLL* constants (includes "winsock2.h") */ 46 47 typedef struct { 48 jint fd; 49 jshort events; 50 } pollfd; 51 52 #define WAKEUP_SOCKET_BUF_SIZE 16 53 54 55 JNIEXPORT jint JNICALL 56 Java_sun_nio_ch_WindowsSelectorImpl_00024SubSelector_poll0(JNIEnv *env, jobject this, 57 jlong pollAddress, jint numfds, 58 jintArray returnReadFds, jintArray returnWriteFds, 59 jintArray returnExceptFds, jlong timeout) 60 { 61 DWORD result = 0; 62 pollfd *fds = (pollfd *) pollAddress; 63 int i; 64 FD_SET readfds, writefds, exceptfds; 65 struct timeval timevalue, *tv; 66 static struct timeval zerotime = {0, 0}; 67 int read_count = 0, write_count = 0, except_count = 0; 68 69 #ifdef _WIN64 70 int resultbuf[FD_SETSIZE + 1]; 71 #endif 72 73 if (timeout == 0) { 74 tv = &zerotime; 75 } else if (timeout < 0) { 76 tv = NULL; 77 } else { 78 tv = &timevalue; 79 jlong sec = timeout / 1000; 80 // 81 // struct timeval members are signed 32-bit integers so the 82 // signed 64-bit jlong needs to clamped 83 // 84 if (sec > INT_MAX) { 85 tv->tv_sec = INT_MAX; 86 tv->tv_usec = 0; 87 } else { 88 tv->tv_sec = (long)sec; 89 tv->tv_usec = (long)((timeout % 1000) * 1000); 90 } 91 } 92 93 /* Set FD_SET structures required for select */ 94 for (i = 0; i < numfds; i++) { 95 if (fds[i].events & POLLIN) { 96 readfds.fd_array[read_count] = fds[i].fd; 97 read_count++; 98 } 99 if (fds[i].events & (POLLOUT | POLLCONN)) 100 { 101 writefds.fd_array[write_count] = fds[i].fd; 102 write_count++; 103 } 104 exceptfds.fd_array[except_count] = fds[i].fd; 105 except_count++; 106 } 107 108 readfds.fd_count = read_count; 109 writefds.fd_count = write_count; 110 exceptfds.fd_count = except_count; 111 112 /* Call select */ 113 if ((result = select(0 , &readfds, &writefds, &exceptfds, tv)) 114 == SOCKET_ERROR) { 115 /* Bad error - this should not happen frequently */ 116 /* Iterate over sockets and call select() on each separately */ 117 FD_SET errreadfds, errwritefds, errexceptfds; 118 readfds.fd_count = 0; 119 writefds.fd_count = 0; 120 exceptfds.fd_count = 0; 121 for (i = 0; i < numfds; i++) { 122 /* prepare select structures for the i-th socket */ 123 errreadfds.fd_count = 0; 124 errwritefds.fd_count = 0; 125 if (fds[i].events & POLLIN) { 126 errreadfds.fd_array[0] = fds[i].fd; 127 errreadfds.fd_count = 1; 128 } 129 if (fds[i].events & (POLLOUT | POLLCONN)) 130 { 131 errwritefds.fd_array[0] = fds[i].fd; 132 errwritefds.fd_count = 1; 133 } 134 errexceptfds.fd_array[0] = fds[i].fd; 135 errexceptfds.fd_count = 1; 136 137 /* call select on the i-th socket */ 138 if (select(0, &errreadfds, &errwritefds, &errexceptfds, &zerotime) 139 == SOCKET_ERROR) { 140 /* This socket causes an error. Add it to exceptfds set */ 141 exceptfds.fd_array[exceptfds.fd_count] = fds[i].fd; 142 exceptfds.fd_count++; 143 } else { 144 /* This socket does not cause an error. Process result */ 145 if (errreadfds.fd_count == 1) { 146 readfds.fd_array[readfds.fd_count] = fds[i].fd; 147 readfds.fd_count++; 148 } 149 if (errwritefds.fd_count == 1) { 150 writefds.fd_array[writefds.fd_count] = fds[i].fd; 151 writefds.fd_count++; 152 } 153 if (errexceptfds.fd_count == 1) { 154 exceptfds.fd_array[exceptfds.fd_count] = fds[i].fd; 155 exceptfds.fd_count++; 156 } 157 } 158 } 159 } 160 161 /* Return selected sockets. */ 162 /* Each Java array consists of sockets count followed by sockets list */ 163 164 #ifdef _WIN64 165 resultbuf[0] = readfds.fd_count; 166 for (i = 0; i < (int)readfds.fd_count; i++) { 167 resultbuf[i + 1] = (int)readfds.fd_array[i]; 168 } 169 (*env)->SetIntArrayRegion(env, returnReadFds, 0, 170 readfds.fd_count + 1, resultbuf); 171 172 resultbuf[0] = writefds.fd_count; 173 for (i = 0; i < (int)writefds.fd_count; i++) { 174 resultbuf[i + 1] = (int)writefds.fd_array[i]; 175 } 176 (*env)->SetIntArrayRegion(env, returnWriteFds, 0, 177 writefds.fd_count + 1, resultbuf); 178 179 resultbuf[0] = exceptfds.fd_count; 180 for (i = 0; i < (int)exceptfds.fd_count; i++) { 181 resultbuf[i + 1] = (int)exceptfds.fd_array[i]; 182 } 183 (*env)->SetIntArrayRegion(env, returnExceptFds, 0, 184 exceptfds.fd_count + 1, resultbuf); 185 #else 186 (*env)->SetIntArrayRegion(env, returnReadFds, 0, 187 readfds.fd_count + 1, (jint *)&readfds); 188 189 (*env)->SetIntArrayRegion(env, returnWriteFds, 0, 190 writefds.fd_count + 1, (jint *)&writefds); 191 (*env)->SetIntArrayRegion(env, returnExceptFds, 0, 192 exceptfds.fd_count + 1, (jint *)&exceptfds); 193 #endif 194 return 0; 195 } 196 197 JNIEXPORT void JNICALL 198 Java_sun_nio_ch_WindowsSelectorImpl_setWakeupSocket0(JNIEnv *env, jclass this, 199 jint scoutFd) 200 { 201 /* Write one byte into the pipe */ 202 const char byte = 1; 203 send(scoutFd, &byte, 1, 0); 204 } 205 206 JNIEXPORT void JNICALL 207 Java_sun_nio_ch_WindowsSelectorImpl_resetWakeupSocket0(JNIEnv *env, jclass this, 208 jint scinFd) 209 { 210 char bytes[WAKEUP_SOCKET_BUF_SIZE]; 211 long bytesToRead; 212 213 /* Drain socket */ 214 /* Find out how many bytes available for read */ 215 ioctlsocket (scinFd, FIONREAD, &bytesToRead); 216 if (bytesToRead == 0) { 217 return; 218 } 219 /* Prepare corresponding buffer if needed, and then read */ 220 if (bytesToRead > WAKEUP_SOCKET_BUF_SIZE) { 221 char* buf = (char*)malloc(bytesToRead); 222 recv(scinFd, buf, bytesToRead, 0); 223 free(buf); 224 } else { 225 recv(scinFd, bytes, WAKEUP_SOCKET_BUF_SIZE, 0); 226 } 227 } 228 229 JNIEXPORT jboolean JNICALL 230 Java_sun_nio_ch_WindowsSelectorImpl_discardUrgentData(JNIEnv* env, jobject this, 231 jint s) 232 { 233 char data[8]; 234 jboolean discarded = JNI_FALSE; 235 int n; 236 do { 237 n = recv(s, (char*)&data, sizeof(data), MSG_OOB); 238 if (n > 0) { 239 discarded = JNI_TRUE; 240 } 241 } while (n > 0); 242 return discarded; 243 }