Possible concurrency problem with in memmory repositories

[laeubi]

Seen in a PR run here

[ERROR] [b1a45b02-e62e-4055-bce8-326251dc43ac][extension>org.eclipse.tycho:tycho-maven-plugin:5.0.0-SNAPSHOT] Provisioning exception
org.eclipse.equinox.p2.core.ProvisionException: Repository already exists at memory:1702483609144.
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.fail (AbstractRepositoryManager.java:409)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.doCreateRepository (AbstractRepositoryManager.java:294)
    at org.eclipse.equinox.internal.p2.artifact.repository.ArtifactRepositoryManager.createRepository (ArtifactRepositoryManager.java:66)
    at org.eclipse.tycho.p2maven.transport.RemoteArtifactRepositoryManager.createRepository (RemoteArtifactRepositoryManager.java:74)
    at org.eclipse.tycho.p2maven.transport.RemoteArtifactRepositoryManager.createRepository (RemoteArtifactRepositoryManager.java:29)
    at org.eclipse.equinox.internal.p2.repository.helpers.RepositoryHelper.createMemoryComposite (RepositoryHelper.java:130)
    at org.eclipse.equinox.internal.p2.artifact.repository.CompositeArtifactRepository.createMemoryComposite (CompositeArtifactRepository.java:61)
    at org.eclipse.tycho.p2tools.copiedfromp2.AbstractApplication.getCompositeArtifactRepository (AbstractApplication.java:268)
    at org.eclipse.tycho.p2tools.copiedfromp2.AbstractApplication.hasArtifactSources (AbstractApplication.java:280)
    at org.eclipse.tycho.p2tools.copiedfromp2.MirrorApplication.validate (MirrorApplication.java:337)
    at org.eclipse.tycho.p2tools.copiedfromp2.MirrorApplication.run (MirrorApplication.java:220)
    at org.eclipse.tycho.p2tools.MirrorApplicationServiceImpl.mirrorReactor (MirrorApplicationServiceImpl.java:180)
    at org.eclipse.tycho.plugins.p2.repository.AssembleRepositoryMojo.execute (AssembleRepositoryMojo.java:368)
    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$1.run (MojoExecutor.java:162)
    at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
    at io.takari.maven.builder.smart.SmartBuilderImpl.buildProject (SmartBuilderImpl.java:209)
    at io.takari.maven.builder.smart.SmartBuilderImpl$ProjectBuildTask.run (SmartBuilderImpl.java:81)
    at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:539)
    at java.util.concurrent.FutureTask.run (FutureTask.java:264)
    at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1136)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:635)
    at java.lang.Thread.run (Thread.java:840)

[laeubi]

The issue is actually with P2 that tries to find a "new" id by looping through as long as a repository not exits. The problem is that this is not atomic and therefore can fail if the method is called often enough.

• Synchronize on the manager in RepositoryHelper#createMemoryComposite eclipse-equinox/p2#415