J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2004 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.jvmstat.perfdata.monitor.v1_0; |
| 27 | |
| 28 | import sun.jvmstat.monitor.*; |
| 29 | import sun.jvmstat.perfdata.monitor.*; |
| 30 | import java.nio.*; |
| 31 | |
| 32 | /** |
| 33 | * Class representing the 1.0 version of the HotSpot PerfData instrumentation |
| 34 | * buffer header. |
| 35 | * <p> |
| 36 | * The PerfDataBufferPrologue2_0 class supports parsing of the version |
| 37 | * specific portions of the PerfDataPrologue C structure: |
| 38 | * <pre> |
| 39 | * typedef struct { |
| 40 | * ... // handled by superclass |
| 41 | * jint used; // number of PerfData memory bytes used |
| 42 | * jint overflow; // number of bytes of overflow |
| 43 | * jlong mod_time_stamp; // time stamp of the last structural modification |
| 44 | * } PerfDataPrologue |
| 45 | * </pre> |
| 46 | * |
| 47 | * @author Brian Doherty |
| 48 | * @since 1.5 |
| 49 | */ |
| 50 | public class PerfDataBufferPrologue extends AbstractPerfDataBufferPrologue { |
| 51 | |
| 52 | private static final int SUPPORTED_MAJOR_VERSION = 1; |
| 53 | private static final int SUPPORTED_MINOR_VERSION = 0; |
| 54 | |
| 55 | /* |
| 56 | * the following constants must match the field offsets and sizes |
| 57 | * in the PerfDataPrologue structure in perfMemory.hpp |
| 58 | */ |
| 59 | final static int PERFDATA_PROLOG_USED_OFFSET=8; |
| 60 | final static int PERFDATA_PROLOG_USED_SIZE=4; // sizeof(int) |
| 61 | final static int PERFDATA_PROLOG_OVERFLOW_OFFSET=12; |
| 62 | final static int PERFDATA_PROLOG_OVERFLOW_SIZE=4; // sizeof(int) |
| 63 | final static int PERFDATA_PROLOG_MODTIMESTAMP_OFFSET=16; |
| 64 | final static int PERFDATA_PROLOG_MODTIMESTAMP_SIZE=8; // sizeof(long) |
| 65 | final static int PERFDATA_PROLOG_SIZE=24; // sizeof(struct PerfDataProlog) |
| 66 | |
| 67 | // counter names for prologue psuedo counters |
| 68 | final static String PERFDATA_BUFFER_SIZE_NAME = "sun.perfdata.size"; |
| 69 | final static String PERFDATA_BUFFER_USED_NAME = "sun.perfdata.used"; |
| 70 | final static String PERFDATA_OVERFLOW_NAME = "sun.perfdata.overflow"; |
| 71 | final static String PERFDATA_MODTIMESTAMP_NAME = "sun.perfdata.timestamp"; |
| 72 | |
| 73 | /** |
| 74 | * Create an instance of PerfDataBufferPrologue from the given |
| 75 | * ByteBuffer object. |
| 76 | * |
| 77 | * @param byteBuffer the buffer containing the binary header data |
| 78 | */ |
| 79 | public PerfDataBufferPrologue(ByteBuffer byteBuffer) |
| 80 | throws MonitorException { |
| 81 | super(byteBuffer); |
| 82 | assert ((getMajorVersion() == 1) && (getMinorVersion() == 0)); |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * {@inheritDoc} |
| 87 | */ |
| 88 | public boolean supportsAccessible() { |
| 89 | return false; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * {@inheritDoc} |
| 94 | */ |
| 95 | public boolean isAccessible() { |
| 96 | return true; |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * Get the utilization of the instrumentation memory buffer. |
| 101 | * |
| 102 | * @return int - the utilization of the buffer |
| 103 | */ |
| 104 | public int getUsed() { |
| 105 | byteBuffer.position(PERFDATA_PROLOG_USED_OFFSET); |
| 106 | return byteBuffer.getInt(); |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * Get the size of the instrumentation memory buffer. |
| 111 | * |
| 112 | * @return int - the size of the buffer |
| 113 | */ |
| 114 | public int getBufferSize() { |
| 115 | return byteBuffer.capacity(); |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Get the buffer overflow amount. This value is non-zero if the |
| 120 | * HotSpot JVM has overflowed the instrumentation memory buffer. |
| 121 | * The target JVM can be restarted with -XX:PerfDataMemSize=X to |
| 122 | * create a larger memory buffer. |
| 123 | * |
| 124 | * @return int - the size of the buffer |
| 125 | */ |
| 126 | public int getOverflow() { |
| 127 | byteBuffer.position(PERFDATA_PROLOG_OVERFLOW_OFFSET); |
| 128 | return byteBuffer.getInt(); |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * Get the time of last modification for the instrumentation |
| 133 | * memory buffer. This method returns the time, as ticks since the |
| 134 | * start of the target JVM, of the last structural modification to |
| 135 | * the instrumentation buffer. Structural modifications correspond to |
| 136 | * the addition or deletion of instrumentation objects. Updates to |
| 137 | * counter values are not structural modifications. |
| 138 | */ |
| 139 | public long getModificationTimeStamp() { |
| 140 | byteBuffer.position(PERFDATA_PROLOG_MODTIMESTAMP_OFFSET); |
| 141 | return byteBuffer.getLong(); |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * {@inheritDoc} |
| 146 | */ |
| 147 | public int getSize() { |
| 148 | return PERFDATA_PROLOG_SIZE; // sizeof(struct PerfDataProlog) |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * Return an IntBuffer that accesses the used value. This is used |
| 153 | * to create a Monitor object for this value. |
| 154 | * |
| 155 | * @return IntBuffer - a ByteBuffer that accesses the used value |
| 156 | * in the instrumentation buffer header. |
| 157 | * @see #getUsed() |
| 158 | */ |
| 159 | public IntBuffer usedBuffer() { |
| 160 | byteBuffer.position(PERFDATA_PROLOG_USED_OFFSET); |
| 161 | IntBuffer ib = byteBuffer.asIntBuffer(); |
| 162 | ib.limit(1); |
| 163 | return ib; |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * Return an IntBuffer that accesses the size value. This is used |
| 168 | * to create a Monitor object for this value. |
| 169 | * |
| 170 | * @return IntBuffer - a ByteBuffer that accesses the size value |
| 171 | * in the instrumentation buffer header. |
| 172 | * @see #getBufferSize() |
| 173 | */ |
| 174 | public IntBuffer sizeBuffer() { |
| 175 | IntBuffer ib = IntBuffer.allocate(1); |
| 176 | ib.put(byteBuffer.capacity()); |
| 177 | return ib; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * Return an IntBuffer that accesses the overflow value. This is used |
| 182 | * to create a Monitor object for this value. |
| 183 | * |
| 184 | * @return IntBuffer - a ByteBuffer that accesses the overflow value |
| 185 | * in the instrumentation buffer header. |
| 186 | * @see #getOverflow() |
| 187 | */ |
| 188 | public IntBuffer overflowBuffer() { |
| 189 | byteBuffer.position(PERFDATA_PROLOG_OVERFLOW_OFFSET); |
| 190 | IntBuffer ib = byteBuffer.asIntBuffer(); |
| 191 | ib.limit(1); |
| 192 | return ib; |
| 193 | } |
| 194 | |
| 195 | /** |
| 196 | * Return an LongBuffer that accesses the modification timestamp value. |
| 197 | * This is used* to create a Monitor object for this value. |
| 198 | * |
| 199 | * @return LongBuffer - a ByteBuffer that accesses the modification time |
| 200 | * stamp value in the instrumentation buffer header. |
| 201 | * @see #getModificationTimeStamp() |
| 202 | */ |
| 203 | public LongBuffer modificationTimeStampBuffer() { |
| 204 | byteBuffer.position(PERFDATA_PROLOG_MODTIMESTAMP_OFFSET); |
| 205 | LongBuffer lb = byteBuffer.asLongBuffer(); |
| 206 | lb.limit(1); |
| 207 | return lb; |
| 208 | } |
| 209 | } |