[MNG-8670] Fix concurrent builder missing/wrong project events

impl/maven-core/src/main/java/org/apache/maven/lifecycle/internal/concurrent/BuildStep.java

@@ -30,6 +30,8 @@
 import java.util.stream.Stream;
 
 import org.apache.maven.api.Lifecycle;
+import org.apache.maven.api.annotations.Nonnull;
+import org.apache.maven.api.annotations.Nullable;
 import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.project.MavenProject;
 
@@ -39,26 +41,43 @@ public class BuildStep {
     public static final int SCHEDULED = 2;
     public static final int EXECUTED = 3;
     public static final int FAILED = 4;
+    public static final int SKIPPED = 5;
 
     public static final String PLAN = "$plan$";
     public static final String SETUP = "$setup$";
     public static final String TEARDOWN = "$teardown$";
 
+    @Nonnull
     final MavenProject project;
+
+    @Nonnull
     final String name;
+
+    @Nullable
     final Lifecycle.Phase phase;
+
     final Map<Integer, Map<String, MojoExecution>> mojos = new TreeMap<>();
     final Collection<BuildStep> predecessors = new HashSet<>();
     final Collection<BuildStep> successors = new HashSet<>();
     final AtomicInteger status = new AtomicInteger();
     final AtomicBoolean skip = new AtomicBoolean();
+    volatile Exception exception;
 
     public BuildStep(String name, MavenProject project, Lifecycle.Phase phase) {
-        this.name = name;
-        this.project = project;
+        this.name = Objects.requireNonNull(name, "name cannot be null");
+        this.project = Objects.requireNonNull(project, "project cannot be null");
         this.phase = phase;
     }
 
+    public boolean isCreated() {
+        return status.get() == CREATED;
+    }
+
+    public boolean isDone() {
+        int state = status.get();
+        return state == EXECUTED || state == FAILED || state == SKIPPED;
+    }
+
     public Stream<BuildStep> allPredecessors() {
         return preds(new HashSet<>()).stream();
     }

its/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng8648ProjectStartedEventsTest.java → its/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng8648ProjectEventsTest.java

@@ -22,9 +22,9 @@
 
 import org.junit.jupiter.api.Test;
 
-public class MavenITmng8648ProjectStartedEventsTest extends AbstractMavenIntegrationTestCase {
+public class MavenITmng8648ProjectEventsTest extends AbstractMavenIntegrationTestCase {
 
-    public MavenITmng8648ProjectStartedEventsTest() {
+    public MavenITmng8648ProjectEventsTest() {
         super("[4.0.0-rc-4,)");
     }
 
@@ -40,16 +40,28 @@ public void test() throws Exception {
         File projectDir = extractResources("/mng-8648/project");
 
         verifier = newVerifier(projectDir.getAbsolutePath());
-        verifier.addCliArguments("compile", "-b", "concurrent");
-        verifier.execute();
-        verifier.verifyErrorFreeLog();
+        verifier.addCliArguments("compile", "-b", "concurrent", "-T5");
+        try {
+            verifier.execute();
+        } catch (VerificationException expected) {
+        }
 
-        verifier.verifyTextInLog("org.apache.maven.its.mng8648:root:pom:1-SNAPSHOT started");
-        verifier.verifyTextInLog("org.apache.maven.its.mng8648:root:pom:1-SNAPSHOT finished");
-        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-a:jar:1-SNAPSHOT started");
-        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-a:jar:1-SNAPSHOT finished");
-        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-b:jar:1-SNAPSHOT started");
-        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-b:jar:1-SNAPSHOT finished");
+        // The root project is marked as successful with the traditional builder
+        // With the concurrent builder, it gets no finish event and in the reactor summary it is listed as "skipped"
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:root:pom:1-SNAPSHOT ProjectStarted");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:root:pom:1-SNAPSHOT ProjectSucceeded");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-a:jar:1-SNAPSHOT ProjectStarted");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-a:jar:1-SNAPSHOT ProjectSucceeded");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-b:jar:1-SNAPSHOT ProjectStarted");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-b:jar:1-SNAPSHOT ProjectSucceeded");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-c:jar:1-SNAPSHOT ProjectStarted");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-c:jar:1-SNAPSHOT ProjectFailed");
+        // With the traditional builder, project D is not reported at all (it is never even started),
+        // and in the reactor summary it is listed as "skipped".
+        // With the concurrent builder, it should be started and later reported as "skipped"
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-d:jar:1-SNAPSHOT ProjectStarted");
+        verifier.verifyTextInLog("org.apache.maven.its.mng8648:subproject-d:jar:1-SNAPSHOT ProjectSkipped");
+        // Make sure there's no problem with the event spy
         verifier.verifyTextNotInLog("Failed to notify spy org.apache.maven.its.mng8648.ProjectEventSpy");
     }
 }

its/core-it-suite/src/test/java/org/apache/maven/it/TestSuiteOrdering.java

@@ -107,7 +107,7 @@ public TestSuiteOrdering() {
         suite.addTestSuite(MavenITmng8598JvmConfigSubstitutionTest.class);
         suite.addTestSuite(MavenITmng8653AfterAndEachPhasesWithConcurrentBuilderTest.class);
         suite.addTestSuite(MavenITmng5668AfterPhaseExecutionTest.class);
-        suite.addTestSuite(MavenITmng8648ProjectStartedEventsTest.class);
+        suite.addTestSuite(MavenITmng8648ProjectEventsTest.class);
         suite.addTestSuite(MavenITmng8645ConsumerPomDependencyManagementTest.class);
         suite.addTestSuite(MavenITmng8594AtFileTest.class);
         suite.addTestSuite(MavenITmng8561SourceRootTest.class);

its/core-it-suite/src/test/resources/mng-8648/extension/src/main/java/org/apache/maven/its/mng8648/ProjectEventSpy.java

@@ -38,12 +38,17 @@ public void onEvent(Object event) {
             MavenProject project = executionEvent.getProject();
             switch (executionEvent.getType()) {
                 case ProjectStarted:
-                    System.out.println(project.getId() + " started");
-                    projects.put(project.getId(), project);
+                    System.out.println(project.getId() + " " + executionEvent.getType());
+                    MavenProject existing = projects.put(project.getId(), project);
+                    if (existing != null) {
+                        throw new IllegalStateException("Project " + project.getId() + " was already started");
+                    }
                     break;
                 case ProjectSucceeded:
+                case ProjectFailed:
+                case ProjectSkipped:
+                    System.out.println(project.getId() + " " + executionEvent.getType());
                     MavenProject mavenProject = projects.get(project.getId());
-                    System.out.println(project.getId() + " finished");
                     if (mavenProject == null) {
                         throw new IllegalStateException("Project " + project.getId() + " was never started");
                     }

its/core-it-suite/src/test/resources/mng-8648/project/pom.xml

@@ -11,5 +11,7 @@
   <modules>
     <module>subproject-a</module>
     <module>subproject-b</module>
+    <module>subproject-c</module>
+    <module>subproject-d</module>
   </modules>
 </project>

its/core-it-suite/src/test/resources/mng-8648/project/subproject-c/pom.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/maven-v4_0_0.xsd">
+
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.apache.maven.its.mng8648</groupId>
+    <artifactId>root</artifactId>
+    <version>1-SNAPSHOT</version>
+  </parent>
+  <artifactId>subproject-c</artifactId>
+</project>

its/core-it-suite/src/test/resources/mng-8648/project/subproject-c/src/main/java/Foo.java

@@ -0,0 +1,19 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+public class Foo implements Object {}

its/core-it-suite/src/test/resources/mng-8648/project/subproject-d/pom.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/maven-v4_0_0.xsd">
+
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.apache.maven.its.mng8648</groupId>
+    <artifactId>root</artifactId>
+    <version>1-SNAPSHOT</version>
+  </parent>
+  <artifactId>subproject-d</artifactId>
+  <dependencies>
+    <dependency>
+      <groupId>${project.groupId}</groupId>
+      <artifactId>subproject-c</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+  </dependencies>
+</project>