Concurrency exceptions

[delanym]

<?xml version="1.0" encoding="UTF-8"?>
<extensions xmlns="http://maven.apache.org/EXTENSIONS/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/EXTENSIONS/1.0.0 http://maven.apache.org/xsd/core-extensions-1.0.0.xsd">
  <extension>
    <groupId>com.github.pascalgn</groupId>
    <artifactId>properties-maven-extension</artifactId>
    <version>0.4.0</version>
  </extension>
  <extension>
    <groupId>io.github.thunkware</groupId>
    <artifactId>test-profiler</artifactId>
    <version>0.1.2</version>
  </extension>
  <extension>
    <!-- https://github.com/seregamorph/maven-turbo-reactor -->
    <groupId>com.github.seregamorph</groupId>
    <artifactId>maven-turbo-builder</artifactId>
    <version>0.3</version>
  </extension>
  <!--extension>
    <groupId>fr.jcgay.maven</groupId>
    <artifactId>maven-profiler</artifactId>
    <version>3.1.1</version>
  </extension-->
  <extension>
    <groupId>fr.jcgay.maven</groupId>
    <artifactId>maven-notifier</artifactId>
    <version>2.1.2</version>
  </extension>
</extensions>

With the command

./mvnw eu.maveniverse.maven.plugins:toolbox:0.13.4:dependency-versions -X > out.log

is get output

...
[DEBUG] Will execute command line: notify-send Company Parent Build Failed. -t 10 -i /tmp/send-notifications-icons/FAILURE.png -u critical (waiting at most: 10 milliseconds)
[DEBUG] Command <[notify-send Company Parent Build Failed. -t 10 -i /tmp/send-notifications-icons/FAILURE.png -u critical]> takes too long to execute. Do not wait for the result...
java.util.concurrent.TimeoutException
    at java.util.concurrent.FutureTask.get (FutureTask.java:204)
    at fr.jcgay.notification.notifier.executor.RuntimeExecutor.exec (RuntimeExecutor.java:66)
    at fr.jcgay.notification.notifier.notifysend.NotifySendNotifier.send (NotifySendNotifier.java:56)
    at fr.jcgay.maven.notifier.sendnotification.SendNotificationNotifier.fireNotification (SendNotificationNotifier.java:62)
    at fr.jcgay.maven.notifier.AbstractNotifier.onEvent (AbstractNotifier.java:35)
    at fr.jcgay.maven.notifier.NotificationEventSpyChooser.onEvent (NotificationEventSpyChooser.java:47)
    at org.apache.maven.eventspy.internal.EventSpyDispatcher.onEvent (EventSpyDispatcher.java:86)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:908)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:283)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:206)
    at jdk.internal.reflect.DirectMethodHandleAccessor.invoke (DirectMethodHandleAccessor.java:103)
    at java.lang.reflect.Method.invoke (Method.java:580)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:255)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:201)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:361)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:314)
[DEBUG] Profiler: done.
[ERROR] Failed to execute goal eu.maveniverse.maven.plugins:toolbox:0.13.4:dependency-versions (default-cli) on project fn: Execution default-cli of goal eu.maveniverse.maven.plugins:toolbox:0.13.4:dependency-versions failed.: ConcurrentModificationException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal eu.maveniverse.maven.plugins:toolbox:0.13.4:dependency-versions (default-cli) on project fn: Execution default-cli of goal eu.maveniverse.maven.plugins:toolbox:0.13.4:dependency-versions failed.
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:333)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
    at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
    at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
    at com.github.seregamorph.maven.turbo.TurboMojosExecutionStrategy.execute (TurboMojosExecutionStrategy.java:52)
    at com.github.seregamorph.maven.turbo.DelegatingMojosExecutionStrategy.execute (DelegatingMojosExecutionStrategy.java:42)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
    at com.github.seregamorph.maven.turbo.TurboBuilder.lambda$createBuildCallable$1 (TurboBuilder.java:176)
    at com.github.seregamorph.maven.turbo.SignalingExecutorCompletionService.lambda$submit$1 (SignalingExecutorCompletionService.java:50)
    at java.util.concurrent.FutureTask.run (FutureTask.java:317)
    at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:572)
    at java.util.concurrent.FutureTask.run (FutureTask.java:317)
    at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642)
    at java.lang.Thread.run (Thread.java:1583)
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-cli of goal eu.maveniverse.maven.plugins:toolbox:0.13.4:dependency-versions failed.
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:133)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
    at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
    at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
    at com.github.seregamorph.maven.turbo.TurboMojosExecutionStrategy.execute (TurboMojosExecutionStrategy.java:52)
    at com.github.seregamorph.maven.turbo.DelegatingMojosExecutionStrategy.execute (DelegatingMojosExecutionStrategy.java:42)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
    at com.github.seregamorph.maven.turbo.TurboBuilder.lambda$createBuildCallable$1 (TurboBuilder.java:176)
    at com.github.seregamorph.maven.turbo.SignalingExecutorCompletionService.lambda$submit$1 (SignalingExecutorCompletionService.java:50)
    at java.util.concurrent.FutureTask.run (FutureTask.java:317)
    at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:572)
    at java.util.concurrent.FutureTask.run (FutureTask.java:317)
    at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642)
    at java.lang.Thread.run (Thread.java:1583)
Caused by: java.util.ConcurrentModificationException
    at java.util.HashMap.computeIfAbsent (HashMap.java:1229)
    at eu.maveniverse.maven.toolbox.plugin.MojoSupport.getOrCreate (MojoSupport.java:147)
    at eu.maveniverse.maven.toolbox.plugin.MojoSupport.execute (MojoSupport.java:359)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
    at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
    at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
    at com.github.seregamorph.maven.turbo.TurboMojosExecutionStrategy.execute (TurboMojosExecutionStrategy.java:52)
    at com.github.seregamorph.maven.turbo.DelegatingMojosExecutionStrategy.execute (DelegatingMojosExecutionStrategy.java:42)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
    at com.github.seregamorph.maven.turbo.TurboBuilder.lambda$createBuildCallable$1 (TurboBuilder.java:176)
    at com.github.seregamorph.maven.turbo.SignalingExecutorCompletionService.lambda$submit$1 (SignalingExecutorCompletionService.java:50)
    at java.util.concurrent.FutureTask.run (FutureTask.java:317)
    at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:572)
    at java.util.concurrent.FutureTask.run (FutureTask.java:317)
    at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1144)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:642)
    at java.lang.Thread.run (Thread.java:1583)
[ERROR] 
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginExecutionException
[ERROR] 
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <args> -rf :fn
[DEBUG] Shutting down adapter factory; available factories [file-lock, rwlock-local, semaphore-local, noop]; available name mappers [discriminating, file-gav, file-hgav, file-static, gav, static]
[DEBUG] Shutting down 'file-lock' factory
[DEBUG] Shutting down 'rwlock-local' factory
[DEBUG] Shutting down 'semaphore-local' factory
[DEBUG] Shutting down 'noop' factory

[cstamas]

@seregamorph ^ any idea?

[cstamas]

I cannot reproduce this:

[cstamas@angeleyes toolbox-260]$ cat .mvn/extensions.xml 
<?xml version="1.0" encoding="UTF-8"?>
<extensions xmlns="http://maven.apache.org/EXTENSIONS/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/EXTENSIONS/1.0.0 http://maven.apache.org/xsd/core-extensions-1.0.0.xsd">
  <extension>
    <groupId>com.github.pascalgn</groupId>
    <artifactId>properties-maven-extension</artifactId>
    <version>0.4.0</version>
  </extension>
  <extension>
    <groupId>io.github.thunkware</groupId>
    <artifactId>test-profiler</artifactId>
    <version>0.1.2</version>
  </extension>
  <extension>
    <!-- https://github.com/seregamorph/maven-turbo-reactor -->
    <groupId>com.github.seregamorph</groupId>
    <artifactId>maven-turbo-builder</artifactId>
    <version>0.3</version>
  </extension>
  <!--extension>
    <groupId>fr.jcgay.maven</groupId>
    <artifactId>maven-profiler</artifactId>
    <version>3.1.1</version>
  </extension-->
  <extension>
    <groupId>fr.jcgay.maven</groupId>
    <artifactId>maven-notifier</artifactId>
    <version>2.1.2</version>
  </extension>
</extensions>
[cstamas@angeleyes toolbox-260]$ mvn eu.maveniverse.maven.plugins:toolbox:0.13.4:dependency-versions
[WARNING] Failed to initialize spy com.github.pascalgn.maven.properties.EventSpyImpl: One of setGitDir or setWorkTree must be called.
[INFO] Maven Test Profiler 0.1.2 started.
[INFO] Scanning for projects...
[INFO] 
[INFO] ----------------------< org.cstamas.beer:toolbox >----------------------
[INFO] Building toolbox 1.0
[INFO]   from pom.xml
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] Using default mojo ordering DefaultMojosExecutionStrategy
[INFO] 
[INFO] --- toolbox:0.13.4:dependency-versions (default-cli) @ toolbox ---
[INFO] Checking newest versions of managed dependencies (0)
[INFO] Checking newest versions of dependencies (1)
[INFO] * org.apache.maven:maven-core:jar:3.9.10 -> 3.9.11
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.169 s
[INFO] Finished at: 2025-09-17T17:16:35+02:00
[INFO] ------------------------------------------------------------------------
[cstamas@angeleyes toolbox-260]$ 

[cstamas]

Aha, so the build you run it on is multi-module, and @seregamorph automatically goes multi-threaded?
What happens is you use -T1 ?

Toolbox mojos were not envisioned to compete 😄 but will see to fix this.

[seregamorph]

automatically goes multi-threaded?

No, it uses default 1 worker thread unless -T (--threads) parameter is explicitly specified. But I believe on the command line or .mvn/maven.config there are -T1C and -bturbo, right?

I think same problem may happen with the standard multithreaded builder

2. FYI: maven-turbo-builder had several releases, current version is 0.9 (recommend to update)

3. Regarding the failure, I see it happens around

Caused by: java.util.ConcurrentModificationException
    at java.util.HashMap.computeIfAbsent (HashMap.java:1229)
    at eu.maveniverse.maven.toolbox.plugin.MojoSupport.getOrCreate (MojoSupport.java:147)
    at eu.maveniverse.maven.toolbox.plugin.MojoSupport.execute (MojoSupport.java:359)

I don't see how this exception may happen in the same thread, so probably there is concurrent thread accessing same static CONTEXT. I believe this line

boolean seeded = CONTEXT.compareAndSet(null, new HashMap<>());

should be

boolean seeded = CONTEXT.compareAndSet(null, new ConcurrentHashMap<>());

or

boolean seeded = CONTEXT.compareAndSet(null, Collections.synchronizedMap(new HashMap<>()));

as this map is accessed concurrently

[cstamas]

So, there is much more to it. Created PR with fix, and verified it does fix this issue but also other context related ones (ie recorder).