Fix QuarkusMainLauncher not returning exit code

`QuarkusMainLauncher` always returns `0`, because `currentApplication` is set to `null` in `io.quarkus.runtime.ApplicationLifecycleManager#run(io.quarkus.runtime.Application, java.lang.Class<? extends io.quarkus.runtime.QuarkusApplication>, java.util.function.BiConsumer<java.lang.Integer,java.lang.Throwable>, java.lang.String...)`.

This change introduces a new callback to `ApplicationLifecycleManager` used by `StartupActionImpl` to know whether the application was actually started or not.

(cherry picked from commit 8e7c255)

core/deployment/src/main/java/io/quarkus/runner/bootstrap/StartupActionImpl.java

@@ -17,6 +17,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
 
@@ -210,24 +211,20 @@ public int runMainClassBlocking(String... args) throws Exception {
         try {
             AtomicInteger result = new AtomicInteger();
             Class<?> lifecycleManager = Class.forName(ApplicationLifecycleManager.class.getName(), true, runtimeClassLoader);
-            Method getCurrentApplication = lifecycleManager.getDeclaredMethod("getCurrentApplication");
-            Object oldApplication = getCurrentApplication.invoke(null);
-            lifecycleManager.getDeclaredMethod("setDefaultExitCodeHandler", Consumer.class).invoke(null,
-                    new Consumer<Integer>() {
-                        @Override
-                        public void accept(Integer integer) {
-                            result.set(integer);
-                        }
-                    });
-            // force init here
-            Class<?> appClass = Class.forName(className, true, runtimeClassLoader);
-            Method start = appClass.getMethod("main", String[].class);
-            start.invoke(null, (Object) (args == null ? new String[0] : args));
+            AtomicBoolean alreadyStarted = new AtomicBoolean();
+            Method setDefaultExitCodeHandler = lifecycleManager.getDeclaredMethod("setDefaultExitCodeHandler", Consumer.class);
+            Method setAlreadyStartedCallback = lifecycleManager.getDeclaredMethod("setAlreadyStartedCallback", Consumer.class);
 
-            CountDownLatch latch = new CountDownLatch(1);
-            new Thread(new Runnable() {
-                @Override
-                public void run() {
+            try {
+                setDefaultExitCodeHandler.invoke(null, (Consumer<Integer>) result::set);
+                setAlreadyStartedCallback.invoke(null, (Consumer<Boolean>) alreadyStarted::set);
+                // force init here
+                Class<?> appClass = Class.forName(className, true, runtimeClassLoader);
+                Method start = appClass.getMethod("main", String[].class);
+                start.invoke(null, (Object) (args == null ? new String[0] : args));
+
+                CountDownLatch latch = new CountDownLatch(1);
+                new Thread(() -> {
                     try {
                         Class<?> q = Class.forName(Quarkus.class.getName(), true, runtimeClassLoader);
                         q.getMethod("blockingExit").invoke(null);
@@ -236,17 +233,19 @@ public void run() {
                     } finally {
                         latch.countDown();
                     }
+                }).start();
+                latch.await();
+
+                if (alreadyStarted.get()) {
+                    //quarkus was not actually started by the main method
+                    //just return
+                    return 0;
                 }
-            }).start();
-            latch.await();
-
-            Object newApplication = getCurrentApplication.invoke(null);
-            if (oldApplication == newApplication) {
-                //quarkus was not actually started by the main method
-                //just return
-                return 0;
+                return result.get();
+            } finally {
+                setDefaultExitCodeHandler.invoke(null, (Consumer<?>) null);
+                setAlreadyStartedCallback.invoke(null, (Consumer<?>) null);
             }
-            return result.get();
         } finally {
             for (var closeTask : runtimeCloseTasks) {
                 try {

core/runtime/src/main/java/io/quarkus/runtime/ApplicationLifecycleManager.java

@@ -2,7 +2,6 @@
 
 import java.util.List;
 import java.util.Locale;
-import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.Lock;
@@ -51,7 +50,7 @@ public class ApplicationLifecycleManager {
 
     // used by ShutdownEvent to propagate the information about shutdown reason
     public static volatile ShutdownEvent.ShutdownReason shutdownReason = ShutdownEvent.ShutdownReason.STANDARD;
-    private static volatile BiConsumer<Integer, Throwable> defaultExitCodeHandler = new BiConsumer<Integer, Throwable>() {
+    private static final BiConsumer<Integer, Throwable> MAIN_EXIT_CODE_HANDLER = new BiConsumer<>() {
         @Override
         public void accept(Integer integer, Throwable cause) {
             Logger logger = Logger.getLogger(Application.class);
@@ -62,6 +61,12 @@ public void accept(Integer integer, Throwable cause) {
             System.exit(integer);
         }
     };
+    private static final Consumer<Boolean> NOOP_ALREADY_STARTED_CALLBACK = new Consumer<>() {
+        @Override
+        public void accept(Boolean t) {
+        }
+    };
+    private static volatile BiConsumer<Integer, Throwable> defaultExitCodeHandler = MAIN_EXIT_CODE_HANDLER;
 
     private ApplicationLifecycleManager() {
 
@@ -77,8 +82,9 @@ private ApplicationLifecycleManager() {
 
     private static int exitCode = -1;
     private static volatile boolean shutdownRequested;
-    private static Application currentApplication;
+    private static volatile Application currentApplication;
     private static boolean vmShuttingDown;
+    private static Consumer<Boolean> alreadyStartedCallback = NOOP_ALREADY_STARTED_CALLBACK;
 
     private static final boolean IS_WINDOWS = System.getProperty("os.name").toLowerCase(Locale.ENGLISH).contains("windows");
     private static final boolean IS_MAC = System.getProperty("os.name").toLowerCase(Locale.ENGLISH).contains("mac");
@@ -89,17 +95,19 @@ public static void run(Application application, String... args) {
 
     public static void run(Application application, Class<? extends QuarkusApplication> quarkusApplication,
             BiConsumer<Integer, Throwable> exitCodeHandler, String... args) {
+        boolean alreadyStarted;
         stateLock.lock();
-        //in tests, we might pass this method an already started application
-        //in this case we don't shut it down at the end
-        boolean alreadyStarted = application.isStarted();
-        if (shutdownHookThread == null) {
-            registerHooks(exitCodeHandler == null ? defaultExitCodeHandler : exitCodeHandler);
-        }
-        if (currentApplication != null && !shutdownRequested) {
-            throw new IllegalStateException("Quarkus already running");
-        }
         try {
+            //in tests, we might pass this method an already started application
+            //in this case we don't shut it down at the end
+            alreadyStarted = application.isStarted();
+            alreadyStartedCallback.accept(alreadyStarted);
+            if (shutdownHookThread == null) {
+                registerHooks(exitCodeHandler == null ? defaultExitCodeHandler : exitCodeHandler);
+            }
+            if (currentApplication != null && !shutdownRequested) {
+                throw new IllegalStateException("Quarkus already running");
+            }
             exitCode = -1;
             shutdownRequested = false;
             currentApplication = application;
@@ -209,6 +217,7 @@ public static void run(Application application, Class<? extends QuarkusApplicati
             int exceptionExitCode = rootCause instanceof PreventFurtherStepsException
                     ? ((PreventFurtherStepsException) rootCause).getExitCode()
                     : 1;
+            currentApplication = null;
             (exitCodeHandler == null ? defaultExitCodeHandler : exitCodeHandler).accept(exceptionExitCode, e);
             return;
         } finally {
@@ -352,7 +361,9 @@ public static boolean isVmShuttingDown() {
      * @param defaultExitCodeHandler the new default exit handler
      */
     public static void setDefaultExitCodeHandler(BiConsumer<Integer, Throwable> defaultExitCodeHandler) {
-        Objects.requireNonNull(defaultExitCodeHandler);
+        if (defaultExitCodeHandler == null) {
+            defaultExitCodeHandler = MAIN_EXIT_CODE_HANDLER;
+        }
         ApplicationLifecycleManager.defaultExitCodeHandler = defaultExitCodeHandler;
     }
 
@@ -365,8 +376,18 @@ public static void setDefaultExitCodeHandler(BiConsumer<Integer, Throwable> defa
      *
      * @param defaultExitCodeHandler the new default exit handler
      */
+    // Used by StartupActionImpl via reflection
     public static void setDefaultExitCodeHandler(Consumer<Integer> defaultExitCodeHandler) {
-        setDefaultExitCodeHandler((exitCode, cause) -> defaultExitCodeHandler.accept(exitCode));
+        BiConsumer<Integer, Throwable> biConsumer = defaultExitCodeHandler == null ? null
+                : (exitCode, cause) -> defaultExitCodeHandler.accept(exitCode);
+        setDefaultExitCodeHandler(biConsumer);
+    }
+
+    @SuppressWarnings("unused")
+    // Used by StartupActionImpl via reflection
+    public static void setAlreadyStartedCallback(Consumer<Boolean> alreadyStartedCallback) {
+        ApplicationLifecycleManager.alreadyStartedCallback = alreadyStartedCallback != null ? alreadyStartedCallback
+                : NOOP_ALREADY_STARTED_CALLBACK;
     }
 
     /**

integration-tests/picocli-native/src/main/java/io/quarkus/it/picocli/ExitCodeCommand.java

@@ -0,0 +1,17 @@
+package io.quarkus.it.picocli;
+
+import java.util.concurrent.Callable;
+
+import picocli.CommandLine;
+
+@CommandLine.Command(name = "exitcode", versionProvider = DynamicVersionProvider.class)
+public class ExitCodeCommand implements Callable<Integer> {
+
+    @CommandLine.Option(names = "--code")
+    int exitCode;
+
+    @Override
+    public Integer call() {
+        return exitCode;
+    }
+}

integration-tests/picocli-native/src/main/java/io/quarkus/it/picocli/TopTestCommand.java

@@ -5,6 +5,7 @@
 
 @TopCommand
 @CommandLine.Command(name = "test", mixinStandardHelpOptions = true, commandListHeading = "%nCommands:%n", synopsisHeading = "%nUsage: ", optionListHeading = "%nOptions:%n", subcommands = {
+        ExitCodeCommand.class,
         CommandUsedAsParent.class,
         CompletionReflectionCommand.class,
         DefaultValueProviderCommand.class,

integration-tests/picocli-native/src/test/java/io/quarkus/it/picocli/PicocliTest.java

@@ -21,6 +21,16 @@ public class PicocliTest {
 
     private String value;
 
+    @Test
+    public void testExitCode(QuarkusMainLauncher launcher) {
+        LaunchResult result = launcher.launch("exitcode", "--code", Integer.toString(42));
+        assertThat(result.exitCode()).isEqualTo(42);
+        result = launcher.launch("exitcode", "--code", Integer.toString(0));
+        assertThat(result.exitCode()).isEqualTo(0);
+        result = launcher.launch("exitcode", "--code", Integer.toString(2));
+        assertThat(result.exitCode()).isEqualTo(2);
+    }
+
     @Test
     @Launch({ "test-command", "-f", "test.txt", "-f", "test2.txt", "-f", "test3.txt", "-s", "ERROR", "-h", "SOCKS=5.5.5.5",
             "-p", "privateValue", "pos1", "pos2" })

integration-tests/picocli/src/main/java/io/quarkus/it/picocli/ExitCodeCommand.java

@@ -0,0 +1,17 @@
+package io.quarkus.it.picocli;
+
+import java.util.concurrent.Callable;
+
+import picocli.CommandLine;
+
+@CommandLine.Command(name = "exitcode")
+public class ExitCodeCommand implements Callable<Integer> {
+
+    @CommandLine.Option(names = "--code")
+    int exitCode;
+
+    @Override
+    public Integer call() {
+        return exitCode;
+    }
+}

integration-tests/picocli/src/test/java/io/quarkus/it/picocli/TestExitCode.java

@@ -0,0 +1,21 @@
+package io.quarkus.it.picocli;
+
+import static io.quarkus.it.picocli.TestUtils.createConfig;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusProdModeTest;
+
+public class TestExitCode {
+
+    @RegisterExtension
+    static final QuarkusProdModeTest config = createConfig("hello-app", ExitCodeCommand.class)
+            .setCommandLineParameters("--code", "42");
+
+    @Test
+    public void simpleTest() {
+        assertThat(config.getExitCode()).isEqualTo(42);
+    }
+}