#6: Add mallinfo() statistics support to command line version

build.gradle

@@ -39,6 +39,9 @@ application {
 }
 
 jar {
+    from('agent/build/libs/') {
+        include '**.jar'
+    }
     manifest {
         attributes(
                 "Main-Class": application.mainClass.get(),

src/main/java/jdump/cli/CommandLineArguments.java

@@ -36,6 +36,7 @@ private void configure() {
             if (argList.contains("-T")) configuration.wantThreadDumpForAll();
             if (argList.contains("-J")) configuration.wantJfrForAll();
             if (argList.contains("-N")) configuration.wantNmtForAll();
+            if (argList.contains("-M")) configuration.wantMallInfoForAll();
         }
         setDuration(argList);
         setOutputDirectory(argList);
@@ -57,15 +58,16 @@ private static Optional<String> getLastOf(List<String> argList, String parameter
     }
 
     private void showUsageInformation() {
-        System.out.println("Usage: jdump [-f<folder name>] [-A] [-H] [-J] [-d<duration in seconds>] [-N] [-T]");
+        System.out.println("Usage: jdump [-f<folder name>] [-A] [-H] [-J] [-d<duration in seconds>] [-N] [-M] [-T]");
         System.out.println();
         System.out.println("Options:");
         System.out.println("start without options to show UI, if not on a headless system");
         System.out.println("-f<name>: name of the target folder (will be created if non-existent; current working directoy, if empty)");
-        System.out.println("-A: produce all types of dumps for all JVMs running locally");
+        System.out.println("-A: produce all non-agent-based types of dumps for all JVMs running locally");
         System.out.println("-H: produce heap dumps for all JVMs running locally");
         System.out.println("-J: produce JFRs for all JVMs running locally");
         System.out.println("-d<duration in seconds>: the duration selected for the JFRs, in seconds, default: 5");
+        System.out.println("-M: produce mallinfo() stats on Linux with glibc");
         System.out.println("-N: product Native Memory Tracks for all JVMs running locally");
         System.out.println("-T: produce thread dumps for all JVMs running locally");
     }

src/main/java/jdump/dump/Attach.java

@@ -1,19 +1,20 @@
 package jdump.dump;
 
-import com.sun.tools.attach.AttachNotSupportedException;
-import com.sun.tools.attach.VirtualMachine;
-import com.sun.tools.attach.VirtualMachineDescriptor;
+import com.sun.tools.attach.*;
 import sun.tools.attach.HotSpotVirtualMachine;
 
+import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.StandardCopyOption;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  * Helper for attaching to JVMs using the Attach API.
  */
 class Attach {
-
     static final Map<String, HotSpotVirtualMachine> attachedVMs = new HashMap<>();
 
     /**
@@ -47,4 +48,14 @@ static synchronized void detachAll() {
         attachedVMs.clear();
     }
 
+    public synchronized static void loadAgent(VirtualMachineDescriptor vmd, String outputFileName) throws
+            AgentLoadException, IOException, AgentInitializationException {
+        if (!attachedVMs.containsKey(vmd.id())) throw new RuntimeException("JVM not attached");
+        // TODO: Remove hard-coded references to agent versions
+        try (var stream = Attach.class.getResourceAsStream("/agent-1.0-SNAPSHOT.jar")) {
+            File tempFile = File.createTempFile("agent-1.0-SNAPSHOT-", ".jar");
+            Files.copy(Objects.requireNonNull(stream), tempFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
+            attachedVMs.get(vmd.id()).loadAgent(tempFile.getAbsolutePath(), outputFileName);
+        }
+    }
 }

src/main/java/jdump/dump/Configuration.java

@@ -19,6 +19,7 @@ public class Configuration {
     private String outputDirectory = System.getProperty("user.dir");
     private Output.TYPE outputType = Output.TYPE.DIRECTORY;
     private boolean immutable;
+    private boolean wantMallInfoForAll = false;
 
     private Configuration() {
         immutable = true;
@@ -32,6 +33,7 @@ private Configuration(Configuration configuration) {
         this.wantNmtForAll = configuration.wantNmtForAll;
         this.outputDirectory = configuration.outputDirectory;
         this.outputType = Output.TYPE.DIRECTORY;
+        this.wantMallInfoForAll = configuration.wantMallInfoForAll;
         immutable = true;
     }
 
@@ -83,6 +85,14 @@ public Mutable outputType(Output.TYPE outputType) {
             super.outputType(outputType);
             return this;
         }
+
+        public void wantMallInfoForAll() {
+            super.wantMallInfoForAll();
+        }
+    }
+
+    private void wantMallInfoForAll() {
+        this.wantMallInfoForAll = true;
     }
 
     private void outputType(Output.TYPE outputType) {
@@ -129,6 +139,10 @@ public boolean nmtForAllSet() {
         return wantNmtForAll;
     }
 
+    public boolean mallInfoForAllSet() {
+        return wantMallInfoForAll;
+    }
+
     public String outputDirectory() {
         return outputDirectory;
     }

src/main/java/jdump/dump/Dumps.java

@@ -15,6 +15,7 @@ public static void handle(Configuration configuration) {
         if (configuration.threadDumpForAllSet()) new ThreadDump(configuration).performForAll();
         if (configuration.jfrForAllSet()) new JFRDump(configuration).performForAll();
         if (configuration.nmtForAllSet()) new NMTDump(configuration).performForAll();
+        if (configuration.mallInfoForAllSet()) new MallInfoDump(configuration).performForAll();
     }
 
     /**

src/main/java/jdump/dump/MallInfoDump.java

@@ -0,0 +1,39 @@
+package jdump.dump;
+
+import com.sun.tools.attach.AgentInitializationException;
+import com.sun.tools.attach.AgentLoadException;
+import com.sun.tools.attach.AttachNotSupportedException;
+import com.sun.tools.attach.VirtualMachineDescriptor;
+
+import java.io.File;
+import java.io.IOException;
+
+public class MallInfoDump extends HotspotDump {
+    final Configuration configuration;
+
+
+    public MallInfoDump(Configuration configuration) {
+        this.configuration = configuration;
+    }
+
+
+    @Override
+    void performFor(VirtualMachineDescriptor vmd) {
+        try {
+            Attach.to(vmd);
+        } catch (IOException | AttachNotSupportedException e) {
+            throw new RuntimeException("Could not attach to JVM " + vmd.id());
+        }
+        try {
+            System.out.println("Dumping mallinfo() statistics for JVM " + vmd.id());
+            Attach.loadAgent(vmd, configuration.outputDirectory() + File.separator + filenameFor(vmd));
+        } catch (AgentLoadException | IOException | AgentInitializationException e) {
+            throw new RuntimeException("Failed to load agent: " + e);
+        }
+    }
+
+    @Override
+    String filenameFor(VirtualMachineDescriptor vmd) {
+        return "jdump-mallinfo-" + vmd.id() + ".txt";
+    }
+}