J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2003-2006 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.management.snmp.jvminstr; |
| 26 | |
| 27 | |
| 28 | // java imports |
| 29 | // |
| 30 | import java.io.Serializable; |
| 31 | import java.util.List; |
| 32 | import java.util.Map; |
| 33 | import java.util.TreeMap; |
| 34 | |
| 35 | // jmx imports |
| 36 | // |
| 37 | import com.sun.jmx.snmp.SnmpOid; |
| 38 | import com.sun.jmx.snmp.SnmpStatusException; |
| 39 | |
| 40 | // jdmk imports |
| 41 | // |
| 42 | import com.sun.jmx.snmp.agent.SnmpMib; |
| 43 | import com.sun.jmx.snmp.agent.SnmpStandardObjectServer; |
| 44 | |
| 45 | import java.lang.management.MemoryManagerMXBean; |
| 46 | import java.lang.management.GarbageCollectorMXBean; |
| 47 | import java.lang.management.ManagementFactory; |
| 48 | |
| 49 | import sun.management.snmp.jvmmib.JvmMemGCTableMeta; |
| 50 | import sun.management.snmp.util.SnmpCachedData; |
| 51 | import sun.management.snmp.util.SnmpTableCache; |
| 52 | import sun.management.snmp.util.SnmpTableHandler; |
| 53 | import sun.management.snmp.util.MibLogger; |
| 54 | import sun.management.snmp.util.JvmContextFactory; |
| 55 | |
| 56 | /** |
| 57 | * The class is used for implementing the "JvmMemGCTable" table. |
| 58 | */ |
| 59 | public class JvmMemGCTableMetaImpl extends JvmMemGCTableMeta { |
| 60 | |
| 61 | /** |
| 62 | * This class acts as a filter over the SnmpTableHandler |
| 63 | * used for the JvmMemoryManagerTable. It filters out |
| 64 | * (skip) all MemoryManagerMXBean that are not instances of |
| 65 | * GarbageCollectorMXBean so that only Garbage Collectors are |
| 66 | * seen. This is a better solution than relying on |
| 67 | * ManagementFactory.getGarbageCollectorMXBeans() because it makes it |
| 68 | * possible to guarantee the consistency betwen the MemoryManager table |
| 69 | * and the GCTable since both will be sharing the same cache. |
| 70 | **/ |
| 71 | protected static class GCTableFilter { |
| 72 | |
| 73 | /** |
| 74 | * Returns the index that immediately follows the given |
| 75 | * <var>index</var>. The returned index is strictly greater |
| 76 | * than the given <var>index</var>, and is contained in the table. |
| 77 | * <br>If the given <var>index</var> is null, returns the first |
| 78 | * index in the table. |
| 79 | * <br>If there are no index after the given <var>index</var>, |
| 80 | * returns null. |
| 81 | * This method is an optimization for the case where the |
| 82 | * SnmpTableHandler is in fact an instance of SnmpCachedData. |
| 83 | **/ |
| 84 | public SnmpOid getNext(SnmpCachedData datas, SnmpOid index) { |
| 85 | |
| 86 | final boolean dbg = log.isDebugOn(); |
| 87 | |
| 88 | // We're going to loop until we find an instance of |
| 89 | // GarbageCollectorMXBean. First we attempt to find |
| 90 | // the next element whose OID follows the given index. |
| 91 | // If `index' is null, the insertion point is -1 |
| 92 | // (the next is 0 = -insertion - 1) |
| 93 | // |
| 94 | final int insertion = (index==null)?-1:datas.find(index); |
| 95 | if (dbg) log.debug("GCTableFilter","oid="+index+ |
| 96 | " at insertion="+insertion); |
| 97 | |
| 98 | int next; |
| 99 | if (insertion > -1) next = insertion+1; |
| 100 | else next = -insertion -1; |
| 101 | |
| 102 | // Now `next' points to the element that imediately |
| 103 | // follows the given `index'. We're going to loop |
| 104 | // through the table, starting at `next' (included), |
| 105 | // and return the first element which is an instance |
| 106 | // of GarbageCollectorMXBean. |
| 107 | // |
| 108 | for (;next<datas.indexes.length;next++) { |
| 109 | if (dbg) log.debug("GCTableFilter","next="+next); |
| 110 | final Object value = datas.datas[next]; |
| 111 | if (dbg) log.debug("GCTableFilter","value["+next+"]=" + |
| 112 | ((MemoryManagerMXBean)value).getName()); |
| 113 | if (value instanceof GarbageCollectorMXBean) { |
| 114 | // That's the next: return it. |
| 115 | if (dbg) log.debug("GCTableFilter", |
| 116 | ((MemoryManagerMXBean)value).getName() + |
| 117 | " is a GarbageCollectorMXBean."); |
| 118 | return datas.indexes[next]; |
| 119 | } |
| 120 | if (dbg) log.debug("GCTableFilter", |
| 121 | ((MemoryManagerMXBean)value).getName() + |
| 122 | " is not a GarbageCollectorMXBean: " + |
| 123 | value.getClass().getName()); |
| 124 | // skip to next index... |
| 125 | } |
| 126 | return null; |
| 127 | } |
| 128 | |
| 129 | /** |
| 130 | * Returns the index that immediately follows the given |
| 131 | * <var>index</var>. The returned index is strictly greater |
| 132 | * than the given <var>index</var>, and is contained in the table. |
| 133 | * <br>If the given <var>index</var> is null, returns the first |
| 134 | * index in the table. |
| 135 | * <br>If there are no index after the given <var>index</var>, |
| 136 | * returns null. |
| 137 | **/ |
| 138 | public SnmpOid getNext(SnmpTableHandler handler, SnmpOid index) { |
| 139 | |
| 140 | // try to call the optimized method |
| 141 | if (handler instanceof SnmpCachedData) |
| 142 | return getNext((SnmpCachedData)handler, index); |
| 143 | |
| 144 | // too bad - revert to non-optimized generic algorithm |
| 145 | SnmpOid next = index; |
| 146 | do { |
| 147 | next = handler.getNext(next); |
| 148 | final Object value = handler.getData(next); |
| 149 | if (value instanceof GarbageCollectorMXBean) |
| 150 | // That's the next! return it |
| 151 | return next; |
| 152 | // skip to next index... |
| 153 | } while (next != null); |
| 154 | return null; |
| 155 | } |
| 156 | |
| 157 | /** |
| 158 | * Returns the data associated with the given index. |
| 159 | * If the given index is not found, null is returned. |
| 160 | * Note that returning null does not necessarily means that |
| 161 | * the index was not found. |
| 162 | **/ |
| 163 | public Object getData(SnmpTableHandler handler, SnmpOid index) { |
| 164 | final Object value = handler.getData(index); |
| 165 | if (value instanceof GarbageCollectorMXBean) return value; |
| 166 | // Behaves as if there was nothing at this index... |
| 167 | // |
| 168 | return null; |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Returns true if the given <var>index</var> is present. |
| 173 | **/ |
| 174 | public boolean contains(SnmpTableHandler handler, SnmpOid index) { |
| 175 | if (handler.getData(index) instanceof GarbageCollectorMXBean) |
| 176 | return true; |
| 177 | // Behaves as if there was nothing at this index... |
| 178 | // |
| 179 | return false; |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | |
| 184 | private transient JvmMemManagerTableMetaImpl managers = null; |
| 185 | private static GCTableFilter filter = new GCTableFilter(); |
| 186 | |
| 187 | |
| 188 | /** |
| 189 | * Constructor for the table. Initialize metadata for "JvmMemGCTableMeta". |
| 190 | */ |
| 191 | public JvmMemGCTableMetaImpl(SnmpMib myMib, |
| 192 | SnmpStandardObjectServer objserv) { |
| 193 | super(myMib,objserv); |
| 194 | } |
| 195 | |
| 196 | // Returns a pointer to the JvmMemManager meta node - we're going |
| 197 | // to reuse its SnmpTableHandler by filtering out all that is |
| 198 | // not a GarbageCollectorMXBean. |
| 199 | private final JvmMemManagerTableMetaImpl getManagers(SnmpMib mib) { |
| 200 | if (managers == null) { |
| 201 | managers = (JvmMemManagerTableMetaImpl) |
| 202 | mib.getRegisteredTableMeta("JvmMemManagerTable"); |
| 203 | } |
| 204 | return managers; |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * Returns the JvmMemManagerTable SnmpTableHandler |
| 209 | **/ |
| 210 | protected SnmpTableHandler getHandler(Object userData) { |
| 211 | JvmMemManagerTableMetaImpl managerTable= getManagers(theMib); |
| 212 | return managerTable.getHandler(userData); |
| 213 | } |
| 214 | |
| 215 | // See com.sun.jmx.snmp.agent.SnmpMibTable |
| 216 | protected SnmpOid getNextOid(Object userData) |
| 217 | throws SnmpStatusException { |
| 218 | // null means get the first OID. |
| 219 | return getNextOid(null,userData); |
| 220 | } |
| 221 | |
| 222 | // See com.sun.jmx.snmp.agent.SnmpMibTable |
| 223 | protected SnmpOid getNextOid(SnmpOid oid, Object userData) |
| 224 | throws SnmpStatusException { |
| 225 | final boolean dbg = log.isDebugOn(); |
| 226 | try { |
| 227 | if (dbg) log.debug("getNextOid", "previous=" + oid); |
| 228 | |
| 229 | // Get the data handler. |
| 230 | // |
| 231 | SnmpTableHandler handler = getHandler(userData); |
| 232 | if (handler == null) { |
| 233 | // This should never happen. |
| 234 | // If we get here it's a bug. |
| 235 | // |
| 236 | if (dbg) log.debug("getNextOid", "handler is null!"); |
| 237 | throw new |
| 238 | SnmpStatusException(SnmpStatusException.noSuchInstance); |
| 239 | } |
| 240 | |
| 241 | |
| 242 | // Get the next oid, using the GC filter. |
| 243 | // |
| 244 | final SnmpOid next = filter.getNext(handler,oid); |
| 245 | if (dbg) log.debug("getNextOid", "next=" + next); |
| 246 | |
| 247 | // if next is null: we reached the end of the table. |
| 248 | // |
| 249 | if (next == null) |
| 250 | throw new |
| 251 | SnmpStatusException(SnmpStatusException.noSuchInstance); |
| 252 | |
| 253 | return next; |
| 254 | } catch (RuntimeException x) { |
| 255 | // debug. This should never happen. |
| 256 | // |
| 257 | if (dbg) log.debug("getNextOid",x); |
| 258 | throw x; |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | |
| 263 | // See com.sun.jmx.snmp.agent.SnmpMibTable |
| 264 | protected boolean contains(SnmpOid oid, Object userData) { |
| 265 | // Get the handler. |
| 266 | // |
| 267 | SnmpTableHandler handler = getHandler(userData); |
| 268 | |
| 269 | // handler should never be null. |
| 270 | // |
| 271 | if (handler == null) |
| 272 | return false; |
| 273 | return filter.contains(handler,oid); |
| 274 | } |
| 275 | |
| 276 | // See com.sun.jmx.snmp.agent.SnmpMibTable |
| 277 | public Object getEntry(SnmpOid oid) |
| 278 | throws SnmpStatusException { |
| 279 | |
| 280 | if (oid == null) |
| 281 | throw new SnmpStatusException(SnmpStatusException.noSuchInstance); |
| 282 | |
| 283 | // Get the request contextual cache (userData). |
| 284 | // |
| 285 | final Map<Object, Object> m = JvmContextFactory.getUserData(); |
| 286 | |
| 287 | // First look in the request contextual cache: maybe we've already |
| 288 | // created this entry... |
| 289 | // |
| 290 | |
| 291 | // We know in the case of this table that the index is an integer, |
| 292 | // it is thus the first OID arc of the index OID. |
| 293 | // |
| 294 | final long index = oid.getOidArc(0); |
| 295 | |
| 296 | // We're going to use this name to store/retrieve the entry in |
| 297 | // the request contextual cache. |
| 298 | // |
| 299 | // Revisit: Probably better programming to put all these strings |
| 300 | // in some interface. |
| 301 | // |
| 302 | final String entryTag = ((m==null)?null:("JvmMemGCTable.entry." + |
| 303 | index)); |
| 304 | |
| 305 | // If the entry is in the cache, simply return it. |
| 306 | // |
| 307 | if (m != null) { |
| 308 | final Object entry = m.get(entryTag); |
| 309 | if (entry != null) return entry; |
| 310 | } |
| 311 | |
| 312 | // Entry was not in request cache. Make a new one. |
| 313 | // |
| 314 | // Get the data hanler. |
| 315 | // |
| 316 | SnmpTableHandler handler = getHandler(m); |
| 317 | |
| 318 | // handler should never be null. |
| 319 | // |
| 320 | if (handler == null) |
| 321 | throw new SnmpStatusException(SnmpStatusException.noSuchInstance); |
| 322 | |
| 323 | // Use the filter to retrieve only GarabageCollectorMBean data. |
| 324 | // |
| 325 | final Object data = filter.getData(handler,oid); |
| 326 | |
| 327 | // data may be null if the OID we were given is not valid. |
| 328 | // (e.g. it identifies a MemoryManager which is not a |
| 329 | // GarbageCollector) |
| 330 | // |
| 331 | if (data == null) |
| 332 | throw new SnmpStatusException(SnmpStatusException.noSuchInstance); |
| 333 | |
| 334 | // Make a new entryy (transient object that will be kept only |
| 335 | // for the duration of the request. |
| 336 | // |
| 337 | final Object entry = |
| 338 | new JvmMemGCEntryImpl((GarbageCollectorMXBean)data,(int)index); |
| 339 | |
| 340 | // Put the entry in the request cache in case we need it later |
| 341 | // in the processing of the request. Note that we could have |
| 342 | // optimized this by making JvmMemGCEntryImpl extend |
| 343 | // JvmMemManagerEntryImpl, and then make sure that |
| 344 | // JvmMemManagerTableMetaImpl creates an instance of JvmMemGCEntryImpl |
| 345 | // instead of JvmMemManagerEntryImpl when the associated data is |
| 346 | // an instance of GarbageCollectorMXBean. This would have made it |
| 347 | // possible to share the transient entry object. |
| 348 | // As it is, we may have two transient objects that points to |
| 349 | // the same underlying MemoryManagerMXBean (which is definitely |
| 350 | // not a problem - but is only a small dysatisfaction) |
| 351 | // |
| 352 | if (m != null && entry != null) { |
| 353 | m.put(entryTag,entry); |
| 354 | } |
| 355 | |
| 356 | return entry; |
| 357 | } |
| 358 | |
| 359 | static final MibLogger log = new MibLogger(JvmMemGCTableMetaImpl.class); |
| 360 | } |