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/* | |
* Copyright 2021 Andrei Pangin | |
* | |
* Licensed 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. | |
*/ | |
import one.jfr.ClassRef; | |
import one.jfr.Dictionary; | |
import one.jfr.JfrReader; | |
import one.jfr.MethodRef; | |
import one.jfr.StackTrace; | |
import one.jfr.event.Event; | |
import one.jfr.event.EventAggregator; | |
import one.jfr.event.MallocEvent; | |
import java.io.IOException; | |
import java.nio.charset.StandardCharsets; | |
import java.util.Arrays; | |
import java.util.HashMap; | |
import java.util.List; | |
import java.util.Map; | |
/** | |
* Parses .jfr containing 'nativemem' events, | |
* matches 'malloc' and 'free' calls with each other, | |
* and produces the FlameGraph of potential native memory leak sites. | |
*/ | |
public class MallocReport { | |
private static final int FRAME_CPP = 4; | |
private static final int FRAME_KERNEL = 5; | |
private final JfrReader jfr; | |
private final Dictionary<String> methodNames = new Dictionary<>(); | |
public MallocReport(JfrReader jfr) { | |
this.jfr = jfr; | |
} | |
public void convert(final FlameGraph fg, final boolean threads, final boolean total, final boolean ignoreFree) throws IOException { | |
// Read all events to sort them in chronological order | |
List<MallocEvent> events = jfr.readAllEvents(MallocEvent.class); | |
EventAggregator agg = new EventAggregator(threads, total); | |
if (!ignoreFree) { | |
Map<Long, MallocEvent> addresses = new HashMap<>(); | |
for (MallocEvent e : events) { | |
if (e.size > 0) { | |
addresses.put(e.address, e); | |
} else { | |
addresses.remove(e.address); | |
} | |
} | |
for (MallocEvent e : addresses.values()) { | |
agg.collect(e); | |
} | |
} else { | |
for (MallocEvent e : events) { | |
if (e.size > 0) { | |
agg.collect(e); | |
} | |
} | |
} | |
// Don't use lambda for faster startup | |
agg.forEach(new EventAggregator.Visitor() { | |
@Override | |
public void visit(Event event, long value) { | |
StackTrace stackTrace = jfr.stackTraces.get(event.stackTraceId); | |
if (stackTrace != null) { | |
long[] methods = stackTrace.methods; | |
byte[] types = stackTrace.types; | |
int skip = 0; | |
while (skip < types.length && types[skip] == FRAME_CPP) { | |
skip++; | |
} | |
String[] trace = new String[methods.length - skip + (threads ? 1 : 0)]; | |
if (threads) { | |
trace[0] = getThreadFrame(event.tid); | |
} | |
int idx = trace.length; | |
for (int i = skip; i < methods.length; i++) { | |
trace[--idx] = getMethodName(methods[i], types[i]); | |
} | |
fg.addSample(trace, value); | |
} | |
} | |
}); | |
} | |
private String getThreadFrame(int tid) { | |
String threadName = jfr.threads.get(tid); | |
return threadName == null ? "[tid=" + tid + ']' : '[' + threadName + " tid=" + tid + ']'; | |
} | |
private String getMethodName(long methodId, int type) { | |
String result = methodNames.get(methodId); | |
if (result != null) { | |
return result; | |
} | |
MethodRef method = jfr.methods.get(methodId); | |
if (method == null) { | |
result = "unknown"; | |
} else { | |
ClassRef cls = jfr.classes.get(method.cls); | |
byte[] className = jfr.symbols.get(cls.name); | |
byte[] methodName = jfr.symbols.get(method.name); | |
if (className == null || className.length == 0) { | |
String methodStr = new String(methodName, StandardCharsets.UTF_8); | |
result = type == FRAME_KERNEL ? methodStr + "_[k]" : methodStr; | |
} else { | |
String classStr = new String(className, StandardCharsets.UTF_8); | |
String methodStr = new String(methodName, StandardCharsets.UTF_8); | |
result = classStr + '.' + methodStr + "_[j]"; | |
} | |
} | |
methodNames.put(methodId, result); | |
return result; | |
} | |
public static void main(String[] args) throws Exception { | |
FlameGraph fg = new FlameGraph(args); | |
if (fg.input == null) { | |
System.out.println("Usage: java " + MallocReport.class.getName() + " [options] input.jfr [output.html]"); | |
System.out.println(); | |
System.out.println("options include all supported FlameGraph options, plus the following:"); | |
System.out.println(" --threads Split profile by threads"); | |
System.out.println(" --ignoreFree Ignore free and report just malloc with size"); | |
System.exit(1); | |
} | |
boolean threads = Arrays.asList(args).contains("--threads"); | |
boolean ignoreFree = Arrays.asList(args).contains("--ignoreFree"); | |
try (JfrReader jfr = new JfrReader(fg.input)) { | |
new MallocReport(jfr).convert(fg, threads, true, ignoreFree); | |
} | |
fg.dump(); | |
} | |
} |
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