added JFR configuration which enables only supported JFR event types

agent/src/main/java/io/pyroscope/javaagent/AsyncProfilerDelegate.java

@@ -27,7 +27,7 @@ public final class AsyncProfilerDelegate implements ProfilerDelegate {
 
     private final AsyncProfiler instance = PyroscopeAsyncProfiler.getAsyncProfiler();
 
-    AsyncProfilerDelegate(Config config) {
+    public AsyncProfilerDelegate(Config config) {
         setConfig(config);
     }
 

agent/src/main/java/io/pyroscope/javaagent/CurrentPidProvider.java

@@ -10,18 +10,17 @@
 
 public class CurrentPidProvider {
     public static int getCurrentProcessId() {
-
         RuntimeMXBean runtime = ManagementFactory.getRuntimeMXBean();
         Field jvm = null;
         try {
             jvm = runtime.getClass().getDeclaredField("jvm");
-        jvm.setAccessible(true);
+            jvm.setAccessible(true);
 
-        VMManagement management = (VMManagement) jvm.get(runtime);
-        Method method = management.getClass().getDeclaredMethod("getProcessId");
-        method.setAccessible(true);
+            VMManagement management = (VMManagement) jvm.get(runtime);
+            Method method = management.getClass().getDeclaredMethod("getProcessId");
+            method.setAccessible(true);
 
-        return (Integer) method.invoke(management);
+            return (Integer) method.invoke(management);
         } catch (NoSuchFieldException | InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
             throw new RuntimeException(e);
         }

agent/src/main/java/io/pyroscope/javaagent/JFRProfilerDelegate.java

@@ -3,31 +3,29 @@
 import io.pyroscope.http.Format;
 import io.pyroscope.javaagent.config.Config;
 import io.pyroscope.labels.Pyroscope;
-import io.pyroscope.labels.io.pyroscope.PyroscopeAsyncProfiler;
-import one.profiler.AsyncProfiler;
-import one.profiler.Counter;
 
-import java.io.DataInputStream;
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.time.Duration;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 
 public final class JFRProfilerDelegate implements ProfilerDelegate {
+    private static final String RECORDING_NAME = "pyroscope";
     private Config config;
     private File tempJFRFile;
+    private Path jcmdBin;
 
-    JFRProfilerDelegate(Config config) {
+    public JFRProfilerDelegate(Config config) {
         setConfig(config);
     }
 
     public void setConfig(final Config config) {
         this.config = config;
-
+        jcmdBin = findJcmdBin();
         try {
             // flight recorder is built on top of a file descriptor, so we need a file.
             tempJFRFile = File.createTempFile("pyroscope", ".jfr");
@@ -43,15 +41,16 @@ public void setConfig(final Config config) {
     public synchronized void start() {
         try {
             List<String> commands = new ArrayList<>();
-            commands.add("jcmd");
+            commands.add(jcmdBin.toString());
             commands.add(String.valueOf(CurrentPidProvider.getCurrentProcessId()));
             commands.add("JFR.start");
-            commands.add("name=Pyroscope");
-            commands.add("filename="+tempJFRFile.getAbsolutePath());
+            commands.add("name=" + RECORDING_NAME);
+            commands.add("filename=" + tempJFRFile.getAbsolutePath());
+            commands.add("settings=pyroscope");
             ProcessBuilder processBuilder = new ProcessBuilder(commands);
             Process process = processBuilder.start();
             int exitCode = process.waitFor();
-            if (exitCode != 0){
+            if (exitCode != 0) {
                 throw new RuntimeException("Invalid exit code: " + exitCode);
             }
         } catch (IOException e) {
@@ -67,14 +66,14 @@ public synchronized void start() {
     public synchronized void stop() {
         try {
             List<String> commands = new ArrayList<>();
-            commands.add("jcmd");
+            commands.add(jcmdBin.toString());
             commands.add(String.valueOf(CurrentPidProvider.getCurrentProcessId()));
             commands.add("JFR.stop");
-            commands.add("name=Pyroscope");
+            commands.add("name=" + RECORDING_NAME);
             ProcessBuilder processBuilder = new ProcessBuilder(commands);
             Process process = processBuilder.start();
             int exitCode = process.waitFor();
-            if (exitCode != 0){
+            if (exitCode != 0) {
                 throw new RuntimeException("Invalid exit code: " + exitCode);
             }
         } catch (IOException e) {
@@ -85,9 +84,8 @@ public synchronized void stop() {
     }
 
     /**
-     *
      * @param started - time when profiling has been started
-     * @param ended - time when profiling has ended
+     * @param ended   - time when profiling has ended
      * @return Profiling data and dynamic labels as {@link Snapshot}
      */
     public synchronized Snapshot dumpProfile(Instant started, Instant ended) {
@@ -98,27 +96,31 @@ private Snapshot dumpImpl(Instant started, Instant ended) {
         if (config.gcBeforeDump) {
             System.gc();
         }
-        final byte[] data;
-            data = dumpJFR();
-        return new Snapshot(
-            Format.JFR,
-            EventType.CPU,
-            started,
-            ended,
-            data,
-            Pyroscope.LabelsWrapper.dump()
-        );
-    }
-
-    private byte[] dumpJFR() {
         try {
-            byte[] bytes = new byte[(int) tempJFRFile.length()];
-            try (DataInputStream ds = new DataInputStream(new FileInputStream(tempJFRFile))) {
-                ds.readFully(bytes);
-            }
-            return bytes;
+            byte[] data = Files.readAllBytes(tempJFRFile.toPath());
+            return new Snapshot(
+                Format.JFR,
+                EventType.CPU,
+                started,
+                ended,
+                data,
+                Pyroscope.LabelsWrapper.dump()
+            );
         } catch (IOException e) {
             throw new IllegalStateException(e);
         }
     }
+
+    private static Path findJcmdBin() {
+        Path javaHome = Paths.get(System.getProperty("java.home"));
+        //find jcmd binary
+        Path jcmdBin = javaHome.resolve("bin/jcmd");
+        if (!Files.isExecutable(jcmdBin)) {
+            jcmdBin = javaHome.getParent().resolve("bin/jcmd");
+            if (!Files.isExecutable(jcmdBin)) {
+                throw new RuntimeException("cannot find executable jcmd in Java home");
+            }
+        }
+        return jcmdBin;
+    }
 }

agent/src/main/java/io/pyroscope/javaagent/ProfilerDelegate.java

@@ -1,10 +1,21 @@
 package io.pyroscope.javaagent;
 
 import io.pyroscope.javaagent.config.Config;
+import io.pyroscope.javaagent.config.ProfilerType;
 
 import java.time.Instant;
 
 public interface ProfilerDelegate {
+    /**
+     * Creates profiler delegate instance based on configuration.
+     *
+     * @param config
+     * @return
+     */
+    static ProfilerDelegate create(Config config) {
+        return config.profilerType.create(config);
+    }
+
     void start();
 
     void stop();

agent/src/main/java/io/pyroscope/javaagent/PyroscopeAgent.java

@@ -76,14 +76,13 @@ private Options(Builder b) {
 
         public static class Builder {
             final Config config;
-            final ProfilerDelegate profiler;
+            ProfilerDelegate profiler;
             Exporter exporter;
             ProfilingScheduler scheduler;
             Logger logger;
 
             public Builder(Config config) {
                 this.config = config;
-                this.profiler = new AsyncProfilerDelegate(config);
             }
 
             public Builder setExporter(Exporter exporter) {
@@ -115,6 +114,9 @@ public Options build() {
                         scheduler = new SamplingProfilingScheduler(config, exporter, logger);
                     }
                 }
+                if (profiler == null) {
+                    profiler = ProfilerDelegate.create(config);
+                }
                 return new Options(this);
             }
         }

agent/src/main/java/io/pyroscope/javaagent/config/Config.java

@@ -90,7 +90,7 @@ public final class Config {
 
     public final boolean agentEnabled;
     public final String applicationName;
-    private final ProfilerType profilerType;
+    public final ProfilerType profilerType;
     public final Duration profilingInterval;
     public final EventType profilingEvent;
     public final String profilingAlloc;
@@ -854,6 +854,11 @@ public Builder setBasicAuthPassword(String basicAuthPassword) {
             return this;
         }
 
+        public Builder setProfilerType(ProfilerType profilerType) {
+            this.profilerType = profilerType;
+            return this;
+        }
+
         public Config build() {
             if (applicationName == null || applicationName.isEmpty()) {
                 applicationName = generateApplicationName();

agent/src/main/java/io/pyroscope/javaagent/config/ProfilerType.java

@@ -1,5 +1,26 @@
 package io.pyroscope.javaagent.config;
 
+import io.pyroscope.javaagent.AsyncProfilerDelegate;
+import io.pyroscope.javaagent.JFRProfilerDelegate;
+import io.pyroscope.javaagent.ProfilerDelegate;
+
+import java.lang.reflect.InvocationTargetException;
+
 public enum ProfilerType {
-    JFR, ASYNC;
+    JFR(JFRProfilerDelegate.class), ASYNC(AsyncProfilerDelegate.class);
+
+    private final Class<? extends ProfilerDelegate> profilerDelegateClass;
+
+    ProfilerType(Class<? extends ProfilerDelegate> profilerDelegateClass) {
+        this.profilerDelegateClass = profilerDelegateClass;
+    }
+
+    public ProfilerDelegate create(Config config) {
+        try {
+            return profilerDelegateClass.getConstructor(Config.class).newInstance(config);
+        } catch (InstantiationException | IllegalAccessException | InvocationTargetException |
+                 NoSuchMethodException e) {
+            throw new RuntimeException(e);
+        }
+    }
 }

agent/src/main/resources/pyroscope.jfc

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<configuration version="2.0" label="Pyroscope"
+               description="Low overhead configuration safe for continuous use in production environments, typically less than 1 % overhead."
+               provider="Pyroscope">
+
+    <event name="jdk.ExecutionSample">
+        <setting name="enabled">true</setting>
+        <setting name="period">1 ms</setting>
+    </event>
+
+    <event name="jdk.ThreadPark">
+        <setting name="enabled">true</setting>
+        <setting name="stackTrace">true</setting>
+        <setting name="threshold">10 ms</setting>
+    </event>
+
+    <event name="jdk.ObjectAllocationInNewTLAB">
+        <setting name="enabled">true</setting>
+        <setting name="stackTrace">true</setting>
+    </event>
+
+    <event name="jdk.ObjectAllocationOutsideTLAB">
+        <setting name="enabled">true</setting>
+        <setting name="stackTrace">true</setting>
+    </event>
+
+    <event name="jdk.JavaMonitorEnter">
+        <setting name="enabled">true</setting>
+        <setting name="stackTrace">true</setting>
+        <setting name="threshold">10 ms</setting>
+    </event>
+
+    <event name="jdk.ThreadPark">
+        <setting name="enabled">true</setting>
+        <setting name="stackTrace">true</setting>
+        <setting name="threshold">10 ms</setting>
+    </event>
+
+    <event name="jdk.ActiveSetting">
+        <setting name="enabled">true</setting>
+    </event>
+
+</configuration>