Merge pull request #488 from gradle/sg/report-jmap

src/main/java/org/gradle/profiler/Main.java

@@ -25,8 +25,10 @@
 import java.io.IOException;
 import java.time.Instant;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.function.Consumer;
+import java.util.stream.Collectors;
 
 public class Main {
     public static void main(String[] args) {
@@ -167,10 +169,14 @@ private static void printResultFileSummaries(File outputDir, Profiler profiler)
         if (outputDir == null) {
             return;
         }
-        for (File file : outputDir.listFiles()) {
-            profiler.summarizeResultFile(file, line -> System.out.println("  " + line));
+        // Report results in a predictable order
+        List<File> results = Arrays.stream(outputDir.listFiles()).sorted().collect(Collectors.toList());
+        for (File file : results) {
+            if (file.isFile()) {
+                profiler.summarizeResultFile(file, line -> System.out.println("  " + line));
+            }
         }
-        for (File file : outputDir.listFiles()) {
+        for (File file : results) {
             if (file.isDirectory()) {
                 printResultFileSummaries(file, profiler);
             }

src/main/java/org/gradle/profiler/heapdump/HeapDumpProfiler.java

@@ -23,7 +23,7 @@ protected void generateInitScriptBody(PrintWriter writer) {
 
     @Override
     public void summarizeResultFile(File resultFile, Consumer<String> consumer) {
-        if (resultFile.getName().endsWith(".hprof")) {
+        if (resultFile.getName().endsWith(".hprof") || resultFile.getName().endsWith(".jmap")) {
             consumer.accept(resultFile.getAbsolutePath());
         }
     }

src/test/groovy/org/gradle/profiler/HeapDumpIntegrationTest.groovy

@@ -1,6 +1,45 @@
 package org.gradle.profiler
 
 class HeapDumpIntegrationTest extends AbstractProfilerIntegrationTest {
+    def "can generate heap dump"() {
+        given:
+        instrumentedBuildScript()
+
+        when:
+        new Main().run("--project-dir", projectDir.absolutePath,
+            "--output-dir", outputDir.absolutePath,
+            "--gradle-version", latestSupportedGradleVersion,
+            "--iterations", "0",
+            "--warmups", "1",
+            "--profile", "heap-dump", "assemble")
+
+        then:
+        // just run one build
+        assertIsHprof("heap-1.hprof")
+        assertIsJmap("heap-1.jmap")
+    }
+
+    private void assertIsHprof(String partialName) {
+        assertHasFile(partialName)
+        // Check the header of the file to see if it looks like a hprof
+        byte[] header = new byte[12]
+        mkFile(partialName).withInputStream {
+            it.read(header)
+        }
+        assert new String(header) == "JAVA PROFILE"
+    }
+
+    private void assertIsJmap(String partialName) {
+        assertHasFile(partialName)
+        def lines = mkFile(partialName).readLines().grep { !it.empty }
+
+        def firstLine = lines.first()
+        assert firstLine.startsWith(" num     #instances         #bytes")
+
+        def lastLine = lines.last()
+        assert lastLine.startsWith("Total ")
+    }
+
     def "generates a heap dump when run with tooling API and warm daemon"() {
         given:
         instrumentedBuildScript()
@@ -10,8 +49,10 @@ class HeapDumpIntegrationTest extends AbstractProfilerIntegrationTest {
 
         then:
         // 2 warm ups and 1 measured build
-        new File(outputDir, "${latestSupportedGradleVersion}-heap-3.hprof").file
-        !new File(outputDir, "${latestSupportedGradleVersion}-heap-4.hprof").file
+        assertHasFile("heap-3.hprof")
+        assertHasFile("heap-3.jmap")
+        assertDoesNotHaveFile("heap-4.hprof")
+        assertDoesNotHaveFile("heap-4.jmap")
     }
 
     def "generates a heap dump when run with tooling API and warm daemon and multiple iterations"() {
@@ -23,7 +64,21 @@ class HeapDumpIntegrationTest extends AbstractProfilerIntegrationTest {
 
         then:
         // 2 warm ups and 2 measured builds
-        new File(outputDir, "${latestSupportedGradleVersion}-heap-3.hprof").file
-        new File(outputDir, "${latestSupportedGradleVersion}-heap-4.hprof").file
+        assertHasFile("heap-3.hprof")
+        assertHasFile("heap-3.jmap")
+        assertHasFile("heap-4.hprof")
+        assertHasFile("heap-4.jmap")
+    }
+
+    private void assertHasFile(String partialName) {
+        assert mkFile(partialName).file
+    }
+
+    private void assertDoesNotHaveFile(String partialName) {
+        assert !mkFile(partialName).exists()
+    }
+
+    private File mkFile(String partialName) {
+        new File(outputDir, "${latestSupportedGradleVersion}-${partialName}")
     }
 }

subprojects/heap-dump/src/main/java/org/gradle/trace/heapdump/HeapDump.java

@@ -12,10 +12,12 @@
 import org.gradle.tooling.events.OperationCompletionListener;
 
 import javax.management.MBeanServer;
+import javax.management.ObjectName;
 import java.io.Closeable;
 import java.io.File;
-import java.io.IOException;
 import java.lang.management.ManagementFactory;
+import java.nio.file.Files;
+import java.util.Collections;
 
 public class HeapDump {
 
@@ -41,12 +43,26 @@ public void onFinish(FinishEvent event) {
         @Override
         public void close() {
             try {
-                File dumpFile = new File(getParameters().getBaseFile().get() + "-heap-" + (++counter) + ".hprof");
-                dumpFile.getParentFile().mkdirs();
+                String dumpFileBase = getParameters().getBaseFile().get() + "-heap-" + (++counter);
+                File hprofFile = new File(dumpFileBase + ".hprof");
+                File jmapFile = new File(dumpFileBase + ".jmap");
+                hprofFile.getParentFile().mkdirs();
+
                 MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+
+                // Dump heap into hprof file
                 HotSpotDiagnosticMXBean mxBean = ManagementFactory.newPlatformMXBeanProxy(server, "com.sun.management:type=HotSpotDiagnostic", HotSpotDiagnosticMXBean.class);
-                mxBean.dumpHeap(dumpFile.getAbsolutePath(), true);
-            } catch (IOException e) {
+                mxBean.dumpHeap(hprofFile.getAbsolutePath(), true);
+
+                // Dump class histogram to .jmap file
+                // This should be the same output as running jmap -histo:live <pid>
+                String histogram = (String) server.invoke(
+                    new ObjectName("com.sun.management:type=DiagnosticCommand"),
+                    "gcClassHistogram",
+                    new Object[]{null},
+                    new String[]{"[Ljava.lang.String;"});
+                Files.write(jmapFile.toPath(), Collections.singleton(histogram));
+            } catch (Exception e) {
                 throw UncheckedException.throwAsUncheckedException(e);
             }
         }