Plugged bad memory leak in project registry

Detach from maven session MavenProject instances associated with
LifecycleMappingMetadataSource, which are stored in project registry
and thus are very long lived. This reduced heap used by registry from
~520M to ~100M for a test workspace with ~60 projects all using same
parent to define lifecycle mapping configuration.

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/LifecycleMappingFactory.java b/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/LifecycleMappingFactory.java
index 2c37468e..9c2dd401 100644
--- a/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/LifecycleMappingFactory.java
+++ b/org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/lifecyclemapping/LifecycleMappingFactory.java
@@ -513,6 +513,7 @@ public class LifecycleMappingFactory {
 
       LifecycleMappingMetadataSource embeddedSource = getEmbeddedMetadataSource(project);
       if(embeddedSource != null) {
+        maven.detachFromSession(project); // don't cache maven session 
         embeddedSource.setSource(project);
         sources.add(embeddedSource);
       }
@@ -521,6 +522,8 @@ public class LifecycleMappingFactory {
         sources.add(referencedSource);
       }
 
+      // TODO ideally, we need to reuse the same parent MavenProject instance in all child modules
+      //      each instance takes ~1M, so we can easily safe 100M+ of heap for larger workspaces
       MavenExecutionRequest request = newMavenExecutionRequest(templateRequest);
       project = maven.resolveParentProject(request, project, monitor);
     } while(project != null);