Report more detail in VM start errors (microsoft#398)

karlvr · testforstephen · web-flow · commit 7f6f76be4fab · 2022-03-17T16:36:39.000+08:00
* Report more detail in VM start errors

Co-authored-by: Jinbo Wang &lt;jinbwan@microsoft.com&gt;
diff --git a/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/LaunchException.java b/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/LaunchException.java
@@ -0,0 +1,51 @@
+/*******************************************************************************
+* Copyright (c) 2018-2021 Microsoft Corporation and others.
+* All rights reserved. This program and the accompanying materials
+* are made available under the terms of the Eclipse Public License v1.0
+* which accompanies this distribution, and is available at
+* http://www.eclipse.org/legal/epl-v10.html
+*
+* Contributors:
+*     Microsoft Corporation - initial API and implementation
+*******************************************************************************/
+
+package com.microsoft.java.debug.core;
+
+import com.sun.jdi.connect.VMStartException;
+
+/**
+ * Extends {@link VMStartException} to provide more detail about the failed process
+ * from before it is destroyed.
+ */
+public class LaunchException extends VMStartException {
+
+    boolean exited;
+    int exitStatus;
+    String stdout;
+    String stderr;
+
+    public LaunchException(String message, Process process, boolean exited, int exitStatus, String stdout, String stderr) {
+        super(message, process);
+        this.exited = exited;
+        this.exitStatus = exitStatus;
+        this.stdout = stdout;
+        this.stderr = stderr;
+    }
+
+    public boolean isExited() {
+        return exited;
+    }
+
+    public int getExitStatus() {
+        return exitStatus;
+    }
+
+    public String getStdout() {
+        return stdout;
+    }
+
+    public String getStderr() {
+        return stderr;
+    }
+
+}
diff --git a/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/LaunchRequestHandler.java b/com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/LaunchRequestHandler.java
@@ -41,6 +41,7 @@
 import com.microsoft.java.debug.core.DebugSettings;
 import com.microsoft.java.debug.core.DebugUtility;
 import com.microsoft.java.debug.core.IDebugSession;
+import com.microsoft.java.debug.core.LaunchException;
 import com.microsoft.java.debug.core.adapter.AdapterUtils;
 import com.microsoft.java.debug.core.adapter.ErrorCode;
 import com.microsoft.java.debug.core.adapter.IDebugAdapterContext;
@@ -245,6 +246,22 @@ protected CompletableFuture<Response> launch(LaunchArguments launchArguments, Re
                 .subscribe((event) -> context.getProtocolServer().sendEvent(event));
             debuggeeConsole.start();
             resultFuture.complete(response);
+        } catch (LaunchException e) {
+            if (StringUtils.isNotBlank(e.getStdout())) {
+                OutputEvent event = convertToOutputEvent(e.getStdout(), Category.stdout, context);
+                context.getProtocolServer().sendEvent(event);
+            }
+            if (StringUtils.isNotBlank(e.getStderr())) {
+                OutputEvent event = convertToOutputEvent(e.getStderr(), Category.stderr, context);
+                context.getProtocolServer().sendEvent(event);
+            }
+
+            resultFuture.completeExceptionally(
+                    new DebugException(
+                            String.format("Failed to launch debuggee VM. Reason: %s", e.getMessage()),
+                            ErrorCode.LAUNCH_FAILURE.getId()
+                    )
+            );
         } catch (IOException | IllegalConnectorArgumentsException | VMStartException e) {
             resultFuture.completeExceptionally(
                     new DebugException(
diff --git a/com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/AdvancedLaunchingConnector.java b/com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/AdvancedLaunchingConnector.java
@@ -13,16 +13,22 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
 
+import org.apache.commons.io.IOUtils;
 import org.eclipse.jdi.internal.VirtualMachineImpl;
 import org.eclipse.jdi.internal.VirtualMachineManagerImpl;
 import org.eclipse.jdi.internal.connect.SocketLaunchingConnectorImpl;
 import org.eclipse.jdi.internal.connect.SocketListeningConnectorImpl;
 
 import com.microsoft.java.debug.core.DebugUtility;
+import com.microsoft.java.debug.core.LaunchException;
 import com.sun.jdi.VirtualMachine;
 import com.sun.jdi.connect.Connector;
 import com.sun.jdi.connect.IllegalConnectorArgumentsException;
@@ -83,18 +89,100 @@ public VirtualMachine launch(Map<String, ? extends Argument> connectionArgs)
         String address = listenConnector.startListening(args);
 
         String[] cmds = constructLaunchCommand(connectionArgs, address);
-        Process process = Runtime.getRuntime().exec(cmds, envVars, workingDir);
 
-        VirtualMachineImpl vm;
+        /* Launch the Java process */
+        final Process process = Runtime.getRuntime().exec(cmds, envVars, workingDir);
+
+        /* A Future that will be completed if we successfully connect to the launched process, or
+           will fail with an Exception if we do not.
+         */
+        final CompletableFuture<VirtualMachineImpl> result = new CompletableFuture<>();
+
+        /* Listen for the debug connection from the Java process */
+        CompletableFuture.runAsync(() -> {
+            try {
+                VirtualMachineImpl vm = (VirtualMachineImpl) listenConnector.accept(args);
+                vm.setLaunchedProcess(process);
+                result.complete(vm);
+            } catch (IllegalConnectorArgumentsException e) {
+                result.completeExceptionally(e);
+            } catch (IOException e) {
+                if (result.isDone()) {
+                    /* The result Future has already been completed by the Process onExit hook */
+                    return;
+                }
+
+                final String stdout = streamToString(process.getInputStream());
+                final String stderr = streamToString(process.getErrorStream());
+
+                process.destroy();
+
+                result.completeExceptionally(new LaunchException(
+                    String.format("VM did not connect within given time: %d ms", ACCEPT_TIMEOUT),
+                    process,
+                    false,
+                    -1,
+                    stdout,
+                    stderr
+                ));
+            } catch (RuntimeException e) {
+                result.completeExceptionally(e);
+            }
+        });
+
+        /* Wait for the Java process to exit; if it exits before the debug connection is made, report it as an error. */
+        process.onExit().thenAcceptAsync(theProcess -> {
+            if (result.isDone()) {
+                /* The result Future has already been completed by successfully connecting to the debug connection */
+                return;
+            }
+
+            final int exitStatus = theProcess.exitValue();
+            final String stdout = streamToString(process.getInputStream());
+            final String stderr = streamToString(process.getErrorStream());
+
+            result.completeExceptionally(new LaunchException(
+                String.format("VM exited with status %d", exitStatus),
+                theProcess,
+                true,
+                exitStatus,
+                stdout,
+                stderr
+            ));
+
+            /* Stop the debug connection attempt */
+            try {
+                listenConnector.stopListening(args);
+            } catch (IOException e) {
+                /* Ignore */
+            }
+        });
+
         try {
-            vm = (VirtualMachineImpl) listenConnector.accept(args);
-        } catch (IOException | IllegalConnectorArgumentsException e) {
-            process.destroy();
-            throw new VMStartException(String.format("VM did not connect within given time: %d ms", ACCEPT_TIMEOUT), process);
+            return result.get();
+        } catch (ExecutionException e) {
+            if (e.getCause() instanceof IOException) {
+                throw (IOException) e.getCause();
+            } else if (e.getCause() instanceof IllegalConnectorArgumentsException) {
+                throw (IllegalConnectorArgumentsException) e.getCause();
+            } else if (e.getCause() instanceof VMStartException) {
+                throw (VMStartException) e.getCause();
+            } else if (e.getCause() instanceof RuntimeException) {
+                throw (RuntimeException) e.getCause();
+            } else {
+                throw new IllegalStateException("Unexpected exception thrown when launching VM", e.getCause());
+            }
+        } catch (InterruptedException e) {
+            throw new VMStartException("VM start interrupted", process);
         }
+    }
 
-        vm.setLaunchedProcess(process);
-        return vm;
+    private String streamToString(final InputStream inputStream) {
+        try {
+            return IOUtils.toString(inputStream, StandardCharsets.UTF_8);
+        } catch (IOException ioe) {
+            return null;
+        }
     }
 
     private static String[] constructLaunchCommand(Map<String, ? extends Argument> launchingOptions, String address) {
