org.netbeans.lib.profiler.heap.StackTraceSegment Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.netbeans.lib.profiler.heap;
import java.util.HashMap;
import java.util.Map;
/**
*
* @author Tomas Hurka
*/
class StackTraceSegment extends TagBounds {
private static final int SERIALNUM_DIV = 16;
//~ Instance fields ----------------------------------------------------------------------------------------------------------
HprofHeap hprofHeap;
final int threadSerialNumberOffset;
final int stackTraceSerialNumberOffset;
final int lengthOffset;
final int framesListOffset;
final int numberOfFramesOffset;
final int timeOffset;
private Map serialNumToStackTrace;
//~ Constructors -------------------------------------------------------------------------------------------------------------
StackTraceSegment(HprofHeap heap, long start, long end) {
super(HprofHeap.STACK_TRACE, start, end);
hprofHeap = heap;
timeOffset = 1;
lengthOffset = timeOffset + 4;
stackTraceSerialNumberOffset = lengthOffset + 4;
threadSerialNumberOffset = stackTraceSerialNumberOffset + 4;
numberOfFramesOffset = threadSerialNumberOffset + 4;
framesListOffset = numberOfFramesOffset + 4;
}
//~ Methods ------------------------------------------------------------------------------------------------------------------
StackTrace getStackTraceBySerialNumber(long stackTraceSerialNumber) {
Long initialOffset;
long[] offset;
initSerialNumToFrame();
initialOffset = (Long) serialNumToStackTrace.get(stackTraceSerialNumber / SERIALNUM_DIV);
if (initialOffset == null) {
initialOffset = new Long(startOffset);
}
offset = new long[] {initialOffset};
while (offset[0] < endOffset) {
long start = offset[0];
long serialNumber = readStackTraceTag(offset);
if (serialNumber == stackTraceSerialNumber) {
return new StackTrace(this, start);
}
}
return null;
}
private HprofByteBuffer getDumpBuffer() {
HprofByteBuffer dumpBuffer = hprofHeap.dumpBuffer;
return dumpBuffer;
}
private int readStackTraceTag(long[] offset) {
long start = offset[0];
if (hprofHeap.readTag(offset) != HprofHeap.STACK_TRACE) {
return 0;
}
return getDumpBuffer().getInt(start + stackTraceSerialNumberOffset);
}
private synchronized void initSerialNumToFrame() {
if (serialNumToStackTrace == null) {
long[] offset = new long[] { startOffset };
serialNumToStackTrace = new HashMap<>();
while (offset[0] < endOffset) {
long start = offset[0];
long serialNumber = readStackTraceTag(offset);
Long serialNumberMask = serialNumber/SERIALNUM_DIV;
Long minOffset = (Long) serialNumToStackTrace.get(serialNumberMask);
if (minOffset == null || minOffset > start) {
serialNumToStackTrace.put(serialNumberMask, start);
}
}
// Systems.debug("serialNumToStackTrace size:"+serialNumToStackTrace.size());
}
}
}
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