| /* |
| * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.management.counter.perf; |
| |
| import sun.management.counter.*; |
| import java.nio.*; |
| |
| class Prologue { |
| // these constants should match their #define counterparts in vmdata.hpp |
| private final static byte PERFDATA_BIG_ENDIAN = 0; |
| private final static byte PERFDATA_LITTLE_ENDIAN = 1; |
| private final static int PERFDATA_MAGIC = 0xcafec0c0; |
| |
| private class PrologueFieldOffset { |
| private final static int SIZEOF_BYTE = 1; |
| private final static int SIZEOF_INT = 4; |
| private final static int SIZEOF_LONG = 8; |
| |
| private final static int MAGIC_SIZE = SIZEOF_INT; |
| private final static int BYTE_ORDER_SIZE = SIZEOF_BYTE; |
| private final static int MAJOR_SIZE = SIZEOF_BYTE; |
| private final static int MINOR_SIZE = SIZEOF_BYTE; |
| private final static int ACCESSIBLE_SIZE = SIZEOF_BYTE; |
| private final static int USED_SIZE = SIZEOF_INT; |
| private final static int OVERFLOW_SIZE = SIZEOF_INT; |
| private final static int MOD_TIMESTAMP_SIZE = SIZEOF_LONG; |
| private final static int ENTRY_OFFSET_SIZE = SIZEOF_INT; |
| private final static int NUM_ENTRIES_SIZE = SIZEOF_INT; |
| |
| // these constants must match the field offsets and sizes |
| // in the PerfDataPrologue structure in perfMemory.hpp |
| final static int MAGIC = 0; |
| final static int BYTE_ORDER = MAGIC + MAGIC_SIZE; |
| final static int MAJOR_VERSION = BYTE_ORDER + BYTE_ORDER_SIZE; |
| final static int MINOR_VERSION = MAJOR_VERSION + MAJOR_SIZE; |
| final static int ACCESSIBLE = MINOR_VERSION + MINOR_SIZE; |
| final static int USED = ACCESSIBLE + ACCESSIBLE_SIZE; |
| final static int OVERFLOW = USED + USED_SIZE; |
| final static int MOD_TIMESTAMP = OVERFLOW + OVERFLOW_SIZE; |
| final static int ENTRY_OFFSET = MOD_TIMESTAMP + MOD_TIMESTAMP_SIZE; |
| final static int NUM_ENTRIES = ENTRY_OFFSET + ENTRY_OFFSET_SIZE; |
| final static int PROLOGUE_2_0_SIZE = NUM_ENTRIES + NUM_ENTRIES_SIZE; |
| } |
| |
| |
| private ByteBuffer header; |
| private int magic; |
| |
| Prologue(ByteBuffer b) { |
| this.header = b.duplicate(); |
| |
| // the magic number is always stored in big-endian format |
| // save and restore the buffer's initial byte order around |
| // the fetch of the data. |
| header.order(ByteOrder.BIG_ENDIAN); |
| header.position(PrologueFieldOffset.MAGIC); |
| magic = header.getInt(); |
| |
| // the magic number is always stored in big-endian format |
| if (magic != PERFDATA_MAGIC) { |
| throw new InstrumentationException("Bad Magic: " + |
| Integer.toHexString(getMagic())); |
| } |
| |
| |
| // set the buffer's byte order according to the value of its |
| // byte order field. |
| header.order(getByteOrder()); |
| |
| // Check version |
| int major = getMajorVersion(); |
| int minor = getMinorVersion(); |
| |
| if (major < 2) { |
| throw new InstrumentationException("Unsupported version: " + |
| major + "." + minor); |
| } |
| |
| // Currently, only support 2.0 version. |
| header.limit(PrologueFieldOffset.PROLOGUE_2_0_SIZE); |
| } |
| |
| public int getMagic() { |
| return magic; |
| } |
| |
| public int getMajorVersion() { |
| header.position(PrologueFieldOffset.MAJOR_VERSION); |
| return (int)header.get(); |
| } |
| |
| public int getMinorVersion() { |
| header.position(PrologueFieldOffset.MINOR_VERSION); |
| return (int)header.get(); |
| } |
| |
| public ByteOrder getByteOrder() { |
| header.position(PrologueFieldOffset.BYTE_ORDER); |
| |
| byte byte_order = header.get(); |
| if (byte_order == PERFDATA_BIG_ENDIAN) { |
| return ByteOrder.BIG_ENDIAN; |
| } |
| else { |
| return ByteOrder.LITTLE_ENDIAN; |
| } |
| } |
| |
| public int getEntryOffset() { |
| header.position(PrologueFieldOffset.ENTRY_OFFSET); |
| return header.getInt(); |
| } |
| |
| // The following fields are updated asynchronously |
| // while they are accessed by these methods. |
| public int getUsed() { |
| header.position(PrologueFieldOffset.USED); |
| return header.getInt(); |
| } |
| |
| public int getOverflow() { |
| header.position(PrologueFieldOffset.OVERFLOW); |
| return header.getInt(); |
| } |
| |
| public long getModificationTimeStamp() { |
| header.position(PrologueFieldOffset.MOD_TIMESTAMP); |
| return header.getLong(); |
| } |
| |
| public int getNumEntries() { |
| header.position(PrologueFieldOffset.NUM_ENTRIES); |
| return header.getInt(); |
| } |
| |
| public boolean isAccessible() { |
| header.position(PrologueFieldOffset.ACCESSIBLE); |
| byte b = header.get(); |
| return (b == 0 ? false : true); |
| } |
| } |