J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 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 | package sun.nio.ch; |
| 27 | |
| 28 | import sun.misc.*; |
| 29 | import java.io.IOException; |
| 30 | import java.util.LinkedList; |
| 31 | |
| 32 | |
| 33 | /** |
| 34 | * Manipulates a native array of pollfd structs on Solaris: |
| 35 | * |
| 36 | * typedef struct pollfd { |
| 37 | * int fd; |
| 38 | * short events; |
| 39 | * short revents; |
| 40 | * } pollfd_t; |
| 41 | * |
| 42 | * @author Mike McCloskey |
| 43 | * @since 1.4 |
| 44 | */ |
| 45 | |
| 46 | class DevPollArrayWrapper { |
| 47 | |
| 48 | // Event masks |
| 49 | static final short POLLIN = 0x0001; |
| 50 | static final short POLLPRI = 0x0002; |
| 51 | static final short POLLOUT = 0x0004; |
| 52 | static final short POLLRDNORM = 0x0040; |
| 53 | static final short POLLWRNORM = POLLOUT; |
| 54 | static final short POLLRDBAND = 0x0080; |
| 55 | static final short POLLWRBAND = 0x0100; |
| 56 | static final short POLLNORM = POLLRDNORM; |
| 57 | static final short POLLERR = 0x0008; |
| 58 | static final short POLLHUP = 0x0010; |
| 59 | static final short POLLNVAL = 0x0020; |
| 60 | static final short POLLREMOVE = 0x0800; |
| 61 | static final short POLLCONN = POLLOUT; |
| 62 | |
| 63 | // Miscellaneous constants |
| 64 | static final short SIZE_POLLFD = 8; |
| 65 | static final short FD_OFFSET = 0; |
| 66 | static final short EVENT_OFFSET = 4; |
| 67 | static final short REVENT_OFFSET = 6; |
| 68 | |
| 69 | // Maximum number of open file descriptors |
| 70 | static final int OPEN_MAX = fdLimit(); |
| 71 | |
| 72 | // Number of pollfd structures to create. |
| 73 | // DP_POLL ioctl allows up to OPEN_MAX-1 |
| 74 | static final int NUM_POLLFDS = Math.min(OPEN_MAX-1, 8192); |
| 75 | |
| 76 | // Base address of the native pollArray |
| 77 | private long pollArrayAddress; |
| 78 | |
| 79 | // Maximum number of POLL_FD structs to update at once |
| 80 | private int MAX_UPDATE_SIZE = 10000; |
| 81 | |
| 82 | DevPollArrayWrapper() { |
| 83 | int allocationSize = NUM_POLLFDS * SIZE_POLLFD; |
| 84 | pollArray = new AllocatedNativeObject(allocationSize, true); |
| 85 | pollArrayAddress = pollArray.address(); |
| 86 | wfd = init(); |
| 87 | |
| 88 | for (int i=0; i<NUM_POLLFDS; i++) { |
| 89 | putDescriptor(i, 0); |
| 90 | putEventOps(i, 0); |
| 91 | putReventOps(i, 0); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | // Machinery for remembering fd registration changes |
| 96 | // A hashmap could be used but the number of changes pending |
| 97 | // is expected to be small |
| 98 | private static class Updator { |
| 99 | int fd; |
| 100 | int mask; |
| 101 | Updator(int fd, int mask) { |
| 102 | this.fd = fd; |
| 103 | this.mask = mask; |
| 104 | } |
| 105 | } |
| 106 | private LinkedList<Updator> updateList = new LinkedList<Updator>(); |
| 107 | |
| 108 | // The pollfd array for results from devpoll driver |
| 109 | private AllocatedNativeObject pollArray; |
| 110 | |
| 111 | // The fd of the devpoll driver |
| 112 | int wfd; |
| 113 | |
| 114 | // The fd of the interrupt line going out |
| 115 | int outgoingInterruptFD; |
| 116 | |
| 117 | // The fd of the interrupt line coming in |
| 118 | int incomingInterruptFD; |
| 119 | |
| 120 | // The index of the interrupt FD |
| 121 | int interruptedIndex; |
| 122 | |
| 123 | // Number of updated pollfd entries |
| 124 | int updated; |
| 125 | |
| 126 | void initInterrupt(int fd0, int fd1) { |
| 127 | outgoingInterruptFD = fd1; |
| 128 | incomingInterruptFD = fd0; |
| 129 | register(wfd, fd0, POLLIN); |
| 130 | } |
| 131 | |
| 132 | void putEventOps(int i, int event) { |
| 133 | int offset = SIZE_POLLFD * i + EVENT_OFFSET; |
| 134 | pollArray.putShort(offset, (short)event); |
| 135 | } |
| 136 | |
| 137 | void putReventOps(int i, int revent) { |
| 138 | int offset = SIZE_POLLFD * i + REVENT_OFFSET; |
| 139 | pollArray.putShort(offset, (short)revent); |
| 140 | } |
| 141 | |
| 142 | void putDescriptor(int i, int fd) { |
| 143 | int offset = SIZE_POLLFD * i + FD_OFFSET; |
| 144 | pollArray.putInt(offset, fd); |
| 145 | } |
| 146 | |
| 147 | int getEventOps(int i) { |
| 148 | int offset = SIZE_POLLFD * i + EVENT_OFFSET; |
| 149 | return pollArray.getShort(offset); |
| 150 | } |
| 151 | |
| 152 | int getReventOps(int i) { |
| 153 | int offset = SIZE_POLLFD * i + REVENT_OFFSET; |
| 154 | return pollArray.getShort(offset); |
| 155 | } |
| 156 | |
| 157 | int getDescriptor(int i) { |
| 158 | int offset = SIZE_POLLFD * i + FD_OFFSET; |
| 159 | return pollArray.getInt(offset); |
| 160 | } |
| 161 | |
| 162 | void setInterest(int fd, int mask) { |
| 163 | synchronized (updateList) { |
| 164 | updateList.add(new Updator(fd, mask)); |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | void release(int fd) { |
| 169 | synchronized (updateList) { |
| 170 | updateList.add(new Updator(fd, POLLREMOVE)); |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | void closeDevPollFD() throws IOException { |
| 175 | FileDispatcher.closeIntFD(wfd); |
| 176 | pollArray.free(); |
| 177 | } |
| 178 | |
| 179 | int poll(long timeout) { |
| 180 | updateRegistrations(); |
| 181 | updated = poll0(pollArrayAddress, NUM_POLLFDS, timeout, wfd); |
| 182 | for (int i=0; i<updated; i++) { |
| 183 | if (getDescriptor(i) == incomingInterruptFD) { |
| 184 | interruptedIndex = i; |
| 185 | interrupted = true; |
| 186 | break; |
| 187 | } |
| 188 | } |
| 189 | return updated; |
| 190 | } |
| 191 | |
| 192 | void updateRegistrations() { |
| 193 | // take snapshot of the updateList size to see if there are |
| 194 | // any registrations to update |
| 195 | int updateSize; |
| 196 | synchronized (updateList) { |
| 197 | updateSize = updateList.size(); |
| 198 | } |
| 199 | if (updateSize > 0) { |
| 200 | // Construct a pollfd array with updated masks; we may overallocate |
| 201 | // by some amount because if the events are already POLLREMOVE |
| 202 | // then the second pollfd of that pair will not be needed. The |
| 203 | // number of entries is limited to a reasonable number to avoid |
| 204 | // allocating a lot of memory. |
| 205 | int maxUpdates = Math.min(updateSize * 2, MAX_UPDATE_SIZE); |
| 206 | int allocationSize = maxUpdates * SIZE_POLLFD; |
| 207 | AllocatedNativeObject updatePollArray = |
| 208 | new AllocatedNativeObject(allocationSize, true); |
| 209 | |
| 210 | try { |
| 211 | synchronized (updateList) { |
| 212 | while (updateList.size() > 0) { |
| 213 | // We have to insert a dummy node in between each |
| 214 | // real update to use POLLREMOVE on the fd first because |
| 215 | // otherwise the changes are simply OR'd together |
| 216 | int index = 0; |
| 217 | Updator u = null; |
| 218 | while ((u = updateList.poll()) != null) { |
| 219 | // First add pollfd struct to clear out this fd |
| 220 | putPollFD(updatePollArray, index, u.fd, |
| 221 | (short)POLLREMOVE); |
| 222 | index++; |
| 223 | // Now add pollfd to update this fd, if necessary |
| 224 | if (u.mask != POLLREMOVE) { |
| 225 | putPollFD(updatePollArray, index, u.fd, |
| 226 | (short)u.mask); |
| 227 | index++; |
| 228 | } |
| 229 | |
| 230 | // Check against the max allocation size; these are |
| 231 | // all we will process. Valid index ranges from 0 to |
| 232 | // (maxUpdates - 1) and we can use up to 2 per loop |
| 233 | if (index > maxUpdates - 2) |
| 234 | break; |
| 235 | } |
| 236 | // Register the changes with /dev/poll |
| 237 | registerMultiple(wfd, updatePollArray.address(), index); |
| 238 | } |
| 239 | } |
| 240 | } finally { |
| 241 | // Free the native array |
| 242 | updatePollArray.free(); |
| 243 | // BUG: If an exception was thrown then the selector now believes |
| 244 | // that the last set of changes was updated but it probably |
| 245 | // was not. This should not be a likely occurrence. |
| 246 | } |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | private void putPollFD(AllocatedNativeObject array, int index, int fd, |
| 251 | short event) |
| 252 | { |
| 253 | int structIndex = SIZE_POLLFD * index; |
| 254 | array.putInt(structIndex + FD_OFFSET, fd); |
| 255 | array.putShort(structIndex + EVENT_OFFSET, event); |
| 256 | array.putShort(structIndex + REVENT_OFFSET, (short)0); |
| 257 | } |
| 258 | |
| 259 | boolean interrupted = false; |
| 260 | |
| 261 | public void interrupt() { |
| 262 | interrupt(outgoingInterruptFD); |
| 263 | } |
| 264 | |
| 265 | public int interruptedIndex() { |
| 266 | return interruptedIndex; |
| 267 | } |
| 268 | |
| 269 | boolean interrupted() { |
| 270 | return interrupted; |
| 271 | } |
| 272 | |
| 273 | void clearInterrupted() { |
| 274 | interrupted = false; |
| 275 | } |
| 276 | |
| 277 | private native int init(); |
| 278 | private native void register(int wfd, int fd, int mask); |
| 279 | private native void registerMultiple(int wfd, long address, int len); |
| 280 | private native int poll0(long pollAddress, int numfds, long timeout, |
| 281 | int wfd); |
| 282 | private static native void interrupt(int fd); |
| 283 | private static native int fdLimit(); |
| 284 | |
| 285 | } |