J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005-2006 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 | package sun.tools.attach; |
| 26 | |
| 27 | import com.sun.tools.attach.VirtualMachine; |
| 28 | import com.sun.tools.attach.AgentLoadException; |
| 29 | import com.sun.tools.attach.AttachNotSupportedException; |
| 30 | import com.sun.tools.attach.spi.AttachProvider; |
| 31 | import java.io.InputStream; |
| 32 | import java.io.IOException; |
| 33 | import java.io.File; |
| 34 | import java.io.FileNotFoundException; |
| 35 | import java.util.Properties; |
| 36 | |
| 37 | /* |
| 38 | * Solaris implementation of HotSpotVirtualMachine. |
| 39 | */ |
| 40 | public class SolarisVirtualMachine extends HotSpotVirtualMachine { |
| 41 | |
| 42 | // door descriptor; |
| 43 | private int fd = -1; |
| 44 | |
| 45 | /** |
| 46 | * Attaches to the target VM |
| 47 | */ |
| 48 | SolarisVirtualMachine(AttachProvider provider, String vmid) |
| 49 | throws AttachNotSupportedException, IOException |
| 50 | { |
| 51 | super(provider, vmid); |
| 52 | // This provider only understands process-ids (pids). |
| 53 | int pid; |
| 54 | try { |
| 55 | pid = Integer.parseInt(vmid); |
| 56 | } catch (NumberFormatException x) { |
| 57 | throw new AttachNotSupportedException("invalid process identifier"); |
| 58 | } |
| 59 | |
| 60 | // Opens the door file to the target VM. If the file is not |
| 61 | // found it might mean that the attach mechanism isn't started in the |
| 62 | // target VM so we attempt to start it and retry. |
| 63 | try { |
| 64 | fd = openDoor(pid); |
| 65 | } catch (FileNotFoundException fnf1) { |
| 66 | File f = createAttachFile(pid); |
| 67 | try { |
| 68 | // kill -QUIT will tickle target VM to check for the |
| 69 | // attach file. |
| 70 | sigquit(pid); |
| 71 | |
| 72 | // give the target VM time to start the attach mechanism |
| 73 | int i = 0; |
| 74 | long delay = 200; |
| 75 | int retries = (int)(attachTimeout() / delay); |
| 76 | do { |
| 77 | try { |
| 78 | Thread.sleep(delay); |
| 79 | } catch (InterruptedException x) { } |
| 80 | try { |
| 81 | fd = openDoor(pid); |
| 82 | } catch (FileNotFoundException fnf2) { } |
| 83 | i++; |
| 84 | } while (i <= retries && fd == -1); |
| 85 | if (fd == -1) { |
| 86 | throw new AttachNotSupportedException( |
| 87 | "Unable to open door: target process not responding or " + |
| 88 | "HotSpot VM not loaded"); |
| 89 | } |
| 90 | } finally { |
| 91 | f.delete(); |
| 92 | } |
| 93 | } |
| 94 | assert fd >= 0; |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * Detach from the target VM |
| 99 | */ |
| 100 | public void detach() throws IOException { |
| 101 | synchronized (this) { |
| 102 | if (fd != -1) { |
| 103 | close(fd); |
| 104 | fd = -1; |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * Execute the given command in the target VM. |
| 111 | */ |
| 112 | InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException { |
| 113 | assert args.length <= 3; // includes null |
| 114 | |
| 115 | // first check that we are still attached |
| 116 | int door; |
| 117 | synchronized (this) { |
| 118 | if (fd == -1) { |
| 119 | throw new IOException("Detached from target VM"); |
| 120 | } |
| 121 | door = fd; |
| 122 | } |
| 123 | |
| 124 | // enqueue the command via a door call |
| 125 | int s = enqueue(door, cmd, args); |
| 126 | assert s >= 0; // valid file descriptor |
| 127 | |
| 128 | // The door call returns a file descriptor (one end of a socket pair). |
| 129 | // Create an input stream around it. |
| 130 | SocketInputStream sis = new SocketInputStream(s); |
| 131 | |
| 132 | // Read the command completion status |
| 133 | int completionStatus; |
| 134 | try { |
| 135 | completionStatus = readInt(sis); |
| 136 | } catch (IOException ioe) { |
| 137 | sis.close(); |
| 138 | throw ioe; |
| 139 | } |
| 140 | |
| 141 | // If non-0 it means an error but we need to special-case the |
| 142 | // "load" command to ensure that the right exception is thrown. |
| 143 | if (completionStatus != 0) { |
| 144 | sis.close(); |
| 145 | if (cmd.equals("load")) { |
| 146 | throw new AgentLoadException("Failed to load agent library"); |
| 147 | } else { |
| 148 | throw new IOException("Command failed in target VM"); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | // Return the input stream so that the command output can be read |
| 153 | return sis; |
| 154 | } |
| 155 | |
| 156 | // InputStream over a socket |
| 157 | private class SocketInputStream extends InputStream { |
| 158 | int s; |
| 159 | |
| 160 | public SocketInputStream(int s) { |
| 161 | this.s = s; |
| 162 | } |
| 163 | |
| 164 | public synchronized int read() throws IOException { |
| 165 | byte b[] = new byte[1]; |
| 166 | int n = this.read(b, 0, 1); |
| 167 | if (n == 1) { |
| 168 | return b[0] & 0xff; |
| 169 | } else { |
| 170 | return -1; |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | public synchronized int read(byte[] bs, int off, int len) throws IOException { |
| 175 | if ((off < 0) || (off > bs.length) || (len < 0) || |
| 176 | ((off + len) > bs.length) || ((off + len) < 0)) { |
| 177 | throw new IndexOutOfBoundsException(); |
| 178 | } else if (len == 0) |
| 179 | return 0; |
| 180 | |
| 181 | return SolarisVirtualMachine.read(s, bs, off, len); |
| 182 | } |
| 183 | |
| 184 | public void close() throws IOException { |
| 185 | SolarisVirtualMachine.close(s); |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | // The door is attached to .java_pid<pid> in the target VM's working |
| 190 | // directory or /tmp. |
| 191 | private int openDoor(int pid) throws IOException { |
| 192 | // First check for a .java_pid<pid> file in the working directory |
| 193 | // of the target process |
| 194 | String fn = ".java_pid" + pid; |
| 195 | String path = "/proc/" + pid + "/cwd/" + fn; |
| 196 | try { |
| 197 | fd = open(path); |
| 198 | } catch (FileNotFoundException fnf) { |
| 199 | path = "/tmp/" + fn; |
| 200 | fd = open(path); |
| 201 | } |
| 202 | |
| 203 | // Check that the file owner/permission to avoid attaching to |
| 204 | // bogus process |
| 205 | try { |
| 206 | checkPermissions(path); |
| 207 | } catch (IOException ioe) { |
| 208 | close(fd); |
| 209 | throw ioe; |
| 210 | } |
| 211 | return fd; |
| 212 | } |
| 213 | |
| 214 | // On Solaris/Linux a simple handshake is used to start the attach mechanism |
| 215 | // if not already started. The client creates a .attach_pid<pid> file in the |
| 216 | // target VM's working directory (or /tmp), and the SIGQUIT handler checks |
| 217 | // for the file. |
| 218 | private File createAttachFile(int pid) throws IOException { |
| 219 | String fn = ".attach_pid" + pid; |
| 220 | String path = "/proc/" + pid + "/cwd/" + fn; |
| 221 | File f = new File(path); |
| 222 | try { |
| 223 | f.createNewFile(); |
| 224 | } catch (IOException x) { |
| 225 | path = "/tmp/" + fn; |
| 226 | f = new File(path); |
| 227 | f.createNewFile(); |
| 228 | } |
| 229 | return f; |
| 230 | } |
| 231 | |
| 232 | //-- native methods |
| 233 | |
| 234 | static native int open(String path) throws IOException; |
| 235 | |
| 236 | static native void close(int fd) throws IOException; |
| 237 | |
| 238 | static native int read(int fd, byte buf[], int off, int buflen) throws IOException; |
| 239 | |
| 240 | static native void checkPermissions(String path) throws IOException; |
| 241 | |
| 242 | static native void sigquit(int pid) throws IOException; |
| 243 | |
| 244 | // enqueue a command (and arguments) to the given door |
| 245 | static native int enqueue(int fd, String cmd, Object ... args) |
| 246 | throws IOException; |
| 247 | |
| 248 | static { |
| 249 | System.loadLibrary("attach"); |
| 250 | } |
| 251 | } |