WIP (still occasional SIGSEGV on OpenJ9)

.gitignore

@@ -1,2 +1,3 @@
 /.idea
 /target
+/dependency-reduced-pom.xml

pom.xml

@@ -10,30 +10,58 @@
 
     <properties>
         <file.encoding>UTF-8</file.encoding>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
     </properties>
 
     <build>
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
-                <version>3.2.0</version>
-                <artifactId>maven-jar-plugin</artifactId>
-                <configuration>
-                    <archive>
-                        <manifest>
-                            <addClasspath>true</addClasspath>
-                            <mainClass>de.steamwar.Main</mainClass>
-                        </manifest>
-                        <manifestEntries>
-                            <Agent-Class>de.steamwar.Agent</Agent-Class>
-                            <Premain-Class>de.steamwar.Agent</Premain-Class>
-                        </manifestEntries>
-                    </archive>
-                </configuration>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.2.4</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <minimizeJar>false</minimizeJar>
+                            <transformers>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <manifestEntries>
+                                        <Main-Class>de.steamwar.Main</Main-Class>
+                                        <Agent-Class>de.steamwar.Agent</Agent-Class>
+                                        <Premain-Class>de.steamwar.Agent</Premain-Class>
+                                    </manifestEntries>
+                                </transformer>
+                            </transformers>
+                        </configuration>
+                    </execution>
+                </executions>
             </plugin>
         </plugins>
         <finalName>LixfelsProfiler</finalName>
     </build>
+
+    <repositories>
+        <repository>
+            <id>fabric</id>
+            <url>https://maven.fabricmc.net/</url>
+        </repository>
+    </repositories>
+
+    <dependencies>
+        <dependency>
+            <groupId>tools.profiler</groupId>
+            <artifactId>async-profiler</artifactId>
+            <version>2.9</version>
+        </dependency>
+        <dependency>
+            <groupId>net.fabricmc</groupId>
+            <artifactId>mapping-io</artifactId>
+            <version>0.3.0</version>
+        </dependency>
+    </dependencies>
 </project>

src/main/java/de/steamwar/Agent.java

@@ -1,32 +1,67 @@
 package de.steamwar;
 
+import one.profiler.AsyncProfiler;
+
+import java.io.IOException;
 import java.lang.instrument.Instrumentation;
 
 public class Agent {
     private Agent() {}
 
-    private static Sampler sampler;
+    private static Thread shutdownHook;
+    private static Instrumentation instrumentation;
+    public static Instrumentation getInstrumentation() {
+        return instrumentation;
+    }
 
     public static void premain(String args, Instrumentation inst) {
-        if ("start".equals(args)) {
-            sampler = new Sampler();
-        }
+        agentmain(args, inst);
     }
 
     public static void agentmain(String args, Instrumentation inst) {
+        instrumentation = inst;
         switch (args) {
             case "start":
-                if(sampler == null)
-                    sampler = new Sampler();
+                start();
                 break;
             case "stop":
-                if(sampler != null)
-                    sampler.stop();
-                sampler = null;
+                stop();
                 break;
             case "heap":
                 OpenJ9.heapdump();
                 break;
         }
     }
+
+    private static void start() {
+        if(shutdownHook != null)
+            return;
+
+        callProfiler("start,event=wall,threads,interval=1000000,alluser"); // 1mio ns = 1ms
+        shutdownHook = new Thread(Agent::stop, "SamplerShutdownHook");
+        Runtime.getRuntime().addShutdownHook(shutdownHook);
+    }
+
+    private static void stop() {
+        if(shutdownHook == null)
+            return;
+
+        AsyncProfiler.getInstance().stop();
+        new Profile(ObfHelper.loadMappingsIfPresent(), callProfiler("collapsed=samples,dot,sig")).save();
+
+        try {
+            Runtime.getRuntime().removeShutdownHook(shutdownHook);
+            shutdownHook = null;
+        } catch (IllegalStateException e) {
+            //ignored
+        }
+    }
+
+    private static String callProfiler(String command) {
+        try {
+            return AsyncProfiler.getInstance().execute(command);
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+    }
 }

src/main/java/de/steamwar/Method.java

@@ -0,0 +1,178 @@
+package de.steamwar;
+
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.text.DecimalFormat;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+public class Method {
+    private static final DecimalFormat df = new DecimalFormat("0.00");
+
+    private static int idCounter;
+
+    private final Profile profile;
+    private final int id;
+    private final String name;
+
+    private final int[] samples = new int[3];
+    private final HashMap<Method, Integer> calls = new HashMap<>();
+
+    public Method(Profile profile, Map<String, ObfHelper.ClassMapping> mappings, String name) {
+        this.profile = profile;
+        this.id = idCounter++;
+
+        int methodDivisor = name.lastIndexOf(".");
+        if(methodDivisor != -1) {
+            String className = name.substring(0, methodDivisor);
+            String methodDefinition = name.substring(methodDivisor+1).replace('|', ';');
+            String methodName = methodDefinition.split("\\(", 2)[0];
+            String methodArgs = methodDefinition.split("\\(", 2)[1].split("\\)", 2)[0];
+            String methodReturn = methodDefinition.split("\\)", 2)[1];
+
+            ObfHelper.ClassMapping mapping = mappings.get(className);
+            if(mapping != null) {
+                className = mapping.mojangName;
+                methodName = mapping.methodsByObf.getOrDefault(methodDefinition, methodName);
+            }
+
+            if(className.contains("$$Lambda$")) {
+                className = className.split("\\$\\$Lambda\\$", 2)[0] + ".λ";
+            }
+
+            if(methodName.startsWith("lambda$")) {
+                methodName = methodName.split("\\$", 2)[1].replace('$', 'λ');
+            }
+
+            StringBuilder builder = new StringBuilder();
+            formatJvmTypes(mappings, builder, methodReturn);
+            builder.append(" ").append(className.replace('$', '.')).append(".").append(methodName).append("(");
+            formatJvmTypes(mappings, builder, methodArgs);
+            builder.append(")");
+
+            name = builder.toString();
+        }
+        this.name = name;
+    }
+
+    private int ownSampleRuns() {
+        return Arrays.stream(samples).sum();
+    }
+
+    private boolean filtered() {
+        return Arrays.stream(samples).sum() < Profile.FILTER;
+    }
+
+    public void add(State state, int samples, Method calling, boolean outsideCycle) {
+        if(outsideCycle)
+            this.samples[state.ordinal()] += samples;
+
+        if (calling != null)
+            calls.compute(calling, (pre, sample) -> sample == null ? samples : sample + samples);
+    }
+
+    private String percentage(int value) {
+        return df.format(value * 100.0 / ownSampleRuns());
+    }
+
+    private String totalPercentage(int value) {
+        return df.format(value * 100.0 / profile.getSampleRuns());
+    }
+
+    private String time(int value) {
+        return df.format(value * Profile.SAMPLING_SPEED / 1e9);
+    }
+
+    public void toDot(OutputStreamWriter writer) throws IOException {
+        if (filtered())
+            return;
+
+        int waiting = samples[State.WAITING.ordinal()];
+        int runnable = samples[State.RUNNING.ordinal()];
+        int blocked = samples[State.BLOCKED.ordinal()];
+        int total = waiting + runnable + blocked;
+
+        int r = (255 * blocked + 192 * waiting) / total;
+        int g = (255 * runnable + 192 * waiting) / total;
+        int b = (192 * waiting) / total;
+        int a = (int) (255 * Math.sqrt(total / (double) profile.getSampleRuns()));
+        if (a > 255)
+            a = 255;
+
+        writer.append(String.valueOf(id)).append(" [fillcolor=\"#").append(String.format("%02X", r)).append(String.format("%02X", g)).append(String.format("%02X", b)).append(String.format("%02X", a)).append("\",label=\"").append(name).append("\\n").append(time(ownSampleRuns())).append("s ").append(totalPercentage(ownSampleRuns())).append("%\\nR").append(percentage(runnable)).append("% B").append(percentage(blocked)).append("% W").append(percentage(waiting)).append("%\"];\n");
+
+        for (Map.Entry<Method, Integer> entry : calls.entrySet()) {
+            if (entry.getKey().filtered() || entry.getValue() < Profile.FILTER)
+                continue;
+
+            writer.append(String.valueOf(id)).append(" -> ").append(String.valueOf(entry.getKey().id)).append(" [label=\"").append(time(entry.getValue())).append("s\\n").append(percentage(entry.getValue())).append("%\",weight=").append(String.valueOf(entry.getValue())).append("];\n");
+        }
+    }
+
+    private void formatJvmTypes(Map<String, ObfHelper.ClassMapping> mappings, StringBuilder builder, String jvmType) {
+        int i = 0;
+        while(i < jvmType.length()) {
+            int arrayDimensions = 0;
+            while(jvmType.charAt(i) == '[') {
+                arrayDimensions++;
+                i++;
+            }
+
+            switch (jvmType.charAt(i)) {
+                case 'B':
+                    builder.append("byte");
+                    i++;
+                    break;
+                case 'C':
+                    builder.append("char");
+                    i++;
+                    break;
+                case 'D':
+                    builder.append("double");
+                    i++;
+                    break;
+                case 'F':
+                    builder.append("float");
+                    i++;
+                    break;
+                case 'I':
+                    builder.append("int");
+                    i++;
+                    break;
+                case 'J':
+                    builder.append("long");
+                    i++;
+                    break;
+                case 'S':
+                    builder.append("short");
+                    i++;
+                    break;
+                case 'Z':
+                    builder.append("boolean");
+                    i++;
+                    break;
+                case 'V':
+                    builder.append("void");
+                    i++;
+                    break;
+                case 'L':
+                    int end = jvmType.indexOf(';', i++);
+                    String className = jvmType.substring(i, end).replace('/', '.');
+                    ObfHelper.ClassMapping mapping = mappings.get(className);
+                    builder.append((mapping == null ? className : mapping.mojangName).replace('$', '.'));
+                    i = end+1;
+                    break;
+                default:
+                    throw new IllegalArgumentException(jvmType + " at " + i);
+            }
+
+            while(arrayDimensions-- > 0) {
+                builder.append("[]");
+            }
+
+            if(i < jvmType.length())
+                builder.append(", ");
+        }
+    }
+}

src/main/java/de/steamwar/ObfHelper.java

@@ -0,0 +1,81 @@
+package de.steamwar;
+
+import net.fabricmc.mappingio.MappingReader;
+import net.fabricmc.mappingio.format.MappingFormat;
+import net.fabricmc.mappingio.tree.MappingTree;
+import net.fabricmc.mappingio.tree.MemoryMappingTree;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+public class ObfHelper {
+    private ObfHelper() {}
+
+    public static final String MOJANG_PLUS_YARN_NAMESPACE = "mojang+yarn";
+    public static final String SPIGOT_NAMESPACE = "spigot";
+
+    public static Map<String, ClassMapping> loadMappingsIfPresent() {
+        for(Class<?> clazz : Agent.getInstrumentation().getAllLoadedClasses()) {
+            if(clazz.getName().equals("io.papermc.paper.util.ObfHelper")) {
+                try (final InputStream mappingsInputStream = clazz.getClassLoader().getResourceAsStream("META-INF/mappings/reobf.tiny")) {
+                    if (mappingsInputStream == null)
+                        return Collections.emptyMap();
+
+                    final MemoryMappingTree tree = new MemoryMappingTree();
+                    MappingReader.read(new InputStreamReader(mappingsInputStream, StandardCharsets.UTF_8), MappingFormat.TINY_2, tree);
+                    Map<String, ClassMapping> classes = new HashMap<>();
+
+                    for (final MappingTree.ClassMapping cls : tree.getClasses()) {
+                        final Map<String, String> methods = new HashMap<>();
+
+                        for (final MappingTree.MethodMapping methodMapping : cls.getMethods()) {
+                            methods.put(
+                                    methodKey(
+                                            methodMapping.getName(SPIGOT_NAMESPACE),
+                                            methodMapping.getDesc(SPIGOT_NAMESPACE)
+                                    ),
+                                    methodMapping.getName(MOJANG_PLUS_YARN_NAMESPACE)
+                            );
+                        }
+
+                        final ClassMapping map = new ClassMapping(
+                                cls.getName(SPIGOT_NAMESPACE).replace('/', '.'),
+                                cls.getName(MOJANG_PLUS_YARN_NAMESPACE).replace('/', '.'),
+                                methods
+                        );
+                        classes.put(map.obfName, map);
+                    }
+
+                    return classes;
+                } catch (final IOException ex) {
+                    System.err.println("Failed to load mappings for stacktrace deobfuscation.");
+                    ex.printStackTrace();
+                    return Collections.emptyMap();
+                }
+            }
+        }
+
+        return Collections.emptyMap();
+    }
+
+    public static String methodKey(final String obfName, final String obfDescriptor) {
+        return obfName + obfDescriptor;
+    }
+
+    public static class ClassMapping {
+        public final String obfName;
+        public final String mojangName;
+        public final Map<String, String> methodsByObf;
+
+        public ClassMapping(String obfName, String mojangName, Map<String, String> methodsByObf) {
+            this.obfName = obfName;
+            this.mojangName = mojangName;
+            this.methodsByObf = methodsByObf;
+        }
+    }
+}

src/main/java/de/steamwar/Profile.java

@@ -0,0 +1,104 @@
+package de.steamwar;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+
+public class Profile {
+
+    public static final long SAMPLING_SPEED = 1000000;
+    public static final int FILTER = 100;
+
+    private static final HashSet<String> waitingMethods = new HashSet<>();
+    static {
+        waitingMethods.add("jdk.internal.misc.Unsafe.park(ZJ)V");
+        waitingMethods.add("java.lang.Thread.sleep(J)V");
+        waitingMethods.add("java.lang.Object.wait(J)V");
+        waitingMethods.add("java.lang.Object.wait(JI)V");
+        waitingMethods.add("java.lang.ref.Reference.waitForReferencePendingList()V");
+        waitingMethods.add("accept");
+        waitingMethods.add("poll");
+        waitingMethods.add("com.ibm.lang.management.internal.MemoryNotificationThread.processNotificationLoop()V");
+        waitingMethods.add("openj9.internal.tools.attach.target.IPC.waitSemaphore()I");
+        waitingMethods.add("net.minecrell.terminalconsole.SimpleTerminalConsole.readCommands(Ljava/io/InputStream|)V");
+        waitingMethods.add("sun.nio.ch.SocketDispatcher.read0(Ljava/io/FileDescriptor|JI)I");
+        waitingMethods.add("io.netty.channel.epoll.Native.epollWait(IJII)I");
+    }
+    //private static final HashSet<String> blockingMethods = new HashSet<>(); For later if possible
+    private static final HashSet<String> omittedMethods = new HashSet<>();
+    static {
+        omittedMethods.add("/usr/lib/libc.so.6");
+        omittedMethods.add("java.lang.Thread.run()V");
+        omittedMethods.add("java.util.concurrent.ForkJoinWorkerThread.run()V");
+        omittedMethods.add("java.util.concurrent.ForkJoinWorkerThread.runWorker(Ljava/util/concurrent/ForkJoinPool$WorkQueue|)V");
+        omittedMethods.add("java.util.concurrent.ThreadPoolExecutor$Worker.run()V");
+        omittedMethods.add("java.util.concurrent.ThreadPoolExecutor.runWorker(Ljava/util/concurrent/ThreadPoolExecutor$Worker|)V");
+    }
+
+    private final HashMap<String, Method> methods = new HashMap<>();
+    private final HashMap<String, Integer> threadSamples = new HashMap<>();
+
+    public Profile(Map<String, ObfHelper.ClassMapping> mappings, String profile) {
+        HashSet<String> previousIds = new HashSet<>();
+        for(String line : profile.split("\n")) {
+            previousIds.clear();
+
+            int sampleDivisor = line.lastIndexOf(" ");
+            int samples = Integer.parseInt(line.substring(sampleDivisor + 1));
+
+            String[] names = line.substring(0, sampleDivisor).split(";");
+            if(names.length <= 1)
+                continue;
+
+            State state = State.RUNNING;
+
+            for(String name : names) {
+                if (waitingMethods.contains(name)) {
+                    state = State.WAITING;
+                    break;
+                }
+            }
+
+            Method calling = null;
+            for(int i = names.length-1; i >= 0; i--) {
+                String name = names[i];
+
+                if(omittedMethods.contains(name))
+                    continue;
+
+                Method method = methods.computeIfAbsent(name, id -> new Method(this, mappings, id));
+                method.add(state, samples, calling, previousIds.add(name));
+                calling = method;
+            }
+
+            threadSamples.compute(names[0], (threadName, previous) -> previous == null ? samples : previous + samples);
+        }
+    }
+
+    public int getSampleRuns() {
+        return threadSamples.values().stream().max(Integer::compareTo).orElse(0);
+    }
+
+    public void save() {
+        File output = new File(System.getProperty("user.home"), "samples.dot");
+        try(OutputStreamWriter writer = new FileWriter(output)) {
+
+            writer.append("digraph {\nnode [shape=plaintext,style=\"filled\", margin=0.1];\n");
+
+            for(Method method : methods.values()) {
+
+                method.toDot(writer);
+            }
+
+            writer.append("}");
+
+            //writer.flush();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

src/main/java/de/steamwar/Sampler.java

@@ -1,171 +0,0 @@
-package de.steamwar;
-
-import java.io.File;
-import java.io.FileWriter;
-import java.io.IOException;
-import java.io.OutputStreamWriter;
-import java.util.*;
-import java.util.concurrent.locks.LockSupport;
-
-public class Sampler {
-
-    public static final long SAMPLING_SPEED = 1000000;
-    public static final int FILTER = 100;
-
-    private static final Set<String> waitingMethods = new HashSet<>();
-    static {
-        waitingMethods.add("io.netty.channel.epoll.Native.epollWait");
-        waitingMethods.add("io.netty.channel.epoll.Native.epollWait0");
-        waitingMethods.add("org.bukkit.craftbukkit.libs.jline.internal.NonBlockingInputStream.read");
-        waitingMethods.add("net.minecrell.terminalconsole.SimpleTerminalConsole.readCommands");
-        waitingMethods.add("com.ibm.lang.management.internal.MemoryNotificationThread.processNotificationLoop");
-        waitingMethods.add("openj9.internal.tools.attach.target.IPC.waitSemaphore");
-        waitingMethods.add("sun.nio.ch.Net.poll");
-        waitingMethods.add("sun.nio.ch.SocketDispatcher.read0");
-        waitingMethods.add("sun.awt.X11.XToolkit.waitForEvents");
-        waitingMethods.add("java.lang.ProcessHandleImpl.waitForProcessExit0");
-        waitingMethods.add("java.lang.ref.Reference.waitForReferencePendingList");
-        waitingMethods.add("java.util.concurrent.locks.LockSupport.parkNanos");
-        waitingMethods.add("java.io.FileInputStream.readBytes");
-    }
-
-    private static final Set<String> omittedMethods = new HashSet<>();
-    static {
-        omittedMethods.add("java.lang.reflect.Method.invoke");
-        omittedMethods.add("java.lang.Thread.run");
-
-        omittedMethods.add("java.util.Iterator.forEachRemaining");
-        omittedMethods.add("java.lang.Iterable.forEach");
-        omittedMethods.add("java.util.ArrayList.forEach");
-        omittedMethods.add("java.util.ArrayList$ArrayListSpliterator.forEachRemaining");
-        omittedMethods.add("java.util.Map.forEach");
-        omittedMethods.add("java.util.HashMap$EntrySpliterator.forEachRemaining");
-        omittedMethods.add("java.util.Spliterators$IteratorSpliterator.forEachRemaining");
-        omittedMethods.add("java.util.Spliterators$ArraySpliterator.forEachRemaining");
-        omittedMethods.add("java.util.concurrent.ThreadPoolExecutor$Worker.run");
-        omittedMethods.add("java.util.concurrent.ThreadPoolExecutor.runWorker");
-        omittedMethods.add("java.util.concurrent.CompletableFuture$Completion.run");
-        omittedMethods.add("java.util.concurrent.CompletableFuture$AsyncSupply.run");
-        omittedMethods.add("java.util.stream.ReferencePipeline.forEach");
-        omittedMethods.add("java.util.stream.ReferencePipeline.collect");
-        omittedMethods.add("java.util.stream.ReferencePipeline$7$1.forEach");
-        omittedMethods.add("java.util.stream.ReferencePipeline$3$1.accept");
-        omittedMethods.add("java.util.stream.AbstractPipeline.evaluate");
-        omittedMethods.add("java.util.stream.AbstractPipeline.wrapAndCopyInto");
-        omittedMethods.add("java.util.stream.AbstractPipeline.copyInto");
-        omittedMethods.add("java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential");
-        omittedMethods.add("java.util.stream.ForEachOps$ForEachOp.evaluateSequential");
-        omittedMethods.add("java.util.stream.ReduceOps$ReduceOp.evaluateSequential");
-        omittedMethods.add("java.util.stream.ReduceOps$1ReducingSink.accept");
-        omittedMethods.add("java.util.stream.Streams$StreamBuilderImpl.forEachRemaining");
-    }
-
-    private final Map<String, Trace> traces = new HashMap<>();
-    private final Thread samplerThread;
-    private final Thread shutdownHook;
-    private boolean shutdown = false;
-
-    private int sampleRuns;
-
-    public Sampler() {
-        samplerThread = new Thread(this::run, "Sampler");
-        samplerThread.setDaemon(true);
-        samplerThread.start();
-        shutdownHook = new Thread(this::stop, "SamplerShutdownHook");
-        Runtime.getRuntime().addShutdownHook(shutdownHook);
-    }
-
-    public int getSampleRuns() {
-        return sampleRuns;
-    }
-
-    public void stop() {
-        shutdown = true;
-        try {
-            samplerThread.join();
-        } catch (InterruptedException e) {
-            Thread.currentThread().interrupt();
-        }
-
-        try {
-            Runtime.getRuntime().removeShutdownHook(shutdownHook);
-        } catch (IllegalStateException e) {
-            //ignored
-        }
-
-        File output = new File(System.getProperty("user.home"), "samples.dot");
-        try {
-            OutputStreamWriter writer = new FileWriter(output);
-            toDot(writer);
-            writer.flush();
-            writer.close();
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    private void run() {
-        long lastTime = System.nanoTime();
-        while(!shutdown) {
-            sample();
-
-            long currentTime = System.nanoTime();
-            LockSupport.parkNanos(SAMPLING_SPEED - currentTime + lastTime);
-            lastTime = currentTime;
-        }
-    }
-
-    private void sample() {
-        sampleRuns++;
-
-        Map<Thread, StackTraceElement[]> stackTraces = Thread.getAllStackTraces();
-        Set<String> previousIds = new HashSet<>();
-
-        for(Map.Entry<Thread, StackTraceElement[]> entry : stackTraces.entrySet()) {
-            Thread thread = entry.getKey();
-            StackTraceElement[] stack = entry.getValue();
-            String threadName = thread.getName();
-            if(stack.length == 0 || threadName.equals("Sampler"))
-                continue;
-
-            previousIds.clear();
-
-            Thread.State state = thread.getState();
-
-            String[] ids = new String[stack.length];
-            for(int i = 0; i < stack.length; i++) {
-                StackTraceElement ste = stack[i];
-                String id = ste.getClassName() + "." + ste.getMethodName();
-                ids[i] = id;
-
-                if (waitingMethods.contains(id))
-                    state = Thread.State.WAITING;
-            }
-
-            Trace predecessor = traces.computeIfAbsent(threadName, name -> new Trace(this, threadName));
-            predecessor.add(state, null);
-
-            for(int i = stack.length - 1; i >= 0; i--) {
-                String id = ids[i];
-
-                if(!previousIds.add(id) || omittedMethods.contains(id))
-                    continue;
-
-                Trace trace = traces.computeIfAbsent(id, id1 -> new Trace(this, id1));
-                trace.add(state, predecessor);
-                predecessor = trace;
-            }
-        }
-    }
-
-    private void toDot(OutputStreamWriter writer) throws IOException {
-        writer.append("digraph {\nnode [shape=plaintext,style=\"filled\", margin=0.1];\n");
-
-        for(Trace trace : traces.values()) {
-            trace.toDot(writer);
-        }
-
-        writer.append("}");
-    }
-
-}

src/main/java/de/steamwar/State.java

@@ -0,0 +1,7 @@
+package de.steamwar;
+
+public enum State {
+    RUNNING,
+    WAITING,
+    BLOCKED
+}

src/main/java/de/steamwar/Trace.java

@@ -1,79 +0,0 @@
-package de.steamwar;
-
-import java.io.IOException;
-import java.io.OutputStreamWriter;
-import java.text.DecimalFormat;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-
-public class Trace {
-    private static final DecimalFormat df = new DecimalFormat("0.00");
-
-    private static int idCounter;
-
-    private final Sampler sampler;
-    private final int id;
-    private final String name;
-
-    private final int[] samples = new int[6];
-    private final Map<Trace, Integer> predecessors = new HashMap<>();
-
-    public Trace(Sampler sampler, String name) {
-        this.sampler = sampler;
-        id = idCounter++;
-        this.name = name;
-    }
-
-    private int ownSampleRuns() {
-        return Arrays.stream(samples).sum();
-    }
-
-    private boolean filtered() {
-        return Arrays.stream(samples).sum() < Sampler.FILTER;
-    }
-
-    public void add(Thread.State state, Trace predecessor) {
-        samples[state.ordinal()] += 1;
-        if (predecessor != null)
-            predecessors.compute(predecessor, (pre, sample) -> sample == null ? 1 : sample + 1);
-    }
-
-    private String percentage(int value) {
-        return df.format(value * 100.0 / ownSampleRuns());
-    }
-
-    private String totalPercentage(int value) {
-        return df.format(value * 100.0 / sampler.getSampleRuns());
-    }
-
-    private String time(int value) {
-        return df.format(value * Sampler.SAMPLING_SPEED / 1e9);
-    }
-
-    public void toDot(OutputStreamWriter writer) throws IOException {
-        if (filtered())
-            return;
-
-        int waiting = samples[3] + samples[4] + samples[5];
-        int runnable = samples[1] + samples[0];
-        int blocked = samples[2];
-        int total = waiting + runnable + blocked;
-
-        int r = (255 * blocked + 192 * waiting) / total;
-        int g = (255 * runnable + 192 * waiting) / total;
-        int b = (192 * waiting) / total;
-        int a = (int) (255 * Math.sqrt(total / (double) sampler.getSampleRuns()));
-        if (a > 255)
-            a = 255;
-
-        writer.append(String.valueOf(id)).append(" [fillcolor=\"#").append(String.format("%02X", r)).append(String.format("%02X", g)).append(String.format("%02X", b)).append(String.format("%02X", a)).append("\",label=\"").append(name).append("\\n").append(time(ownSampleRuns())).append("s ").append(totalPercentage(ownSampleRuns())).append("%\\nR").append(percentage(runnable)).append("% B").append(percentage(blocked)).append("% W").append(percentage(waiting)).append("%\"];\n");
-
-        for (Map.Entry<Trace, Integer> entry : predecessors.entrySet()) {
-            if (entry.getKey().filtered() || entry.getValue() < Sampler.FILTER)
-                continue;
-
-            writer.append(String.valueOf(entry.getKey().id)).append(" -> ").append(String.valueOf(id)).append(" [label=\"").append(time(entry.getValue())).append("s\\n").append(percentage(entry.getValue())).append("%\",weight=").append(String.valueOf(entry.getValue())).append("];\n");
-        }
-    }
-}