diff options
| -rw-r--r-- | plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/mapping/AbstractMappingStrategy.java | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/mapping/AbstractMappingStrategy.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/mapping/AbstractMappingStrategy.java index fe3f2386b2..aeae1c76f3 100644 --- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/mapping/AbstractMappingStrategy.java +++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/mapping/AbstractMappingStrategy.java @@ -60,7 +60,7 @@ import java.util.Set; /** * This abstract base class implements those methods which are most likely common to most mapping strategies. It can be * used to derive custom mapping strategy implementation. - * + * * @author Eike Stepper * @since 2.0 */ @@ -342,7 +342,6 @@ public abstract class AbstractMappingStrategy extends Lifecycle implements IMapp private Set<IDBTable> getModelTables() { Set<IDBTable> tables = new HashSet<IDBTable>(); - for (IClassMapping mapping : classMappings.values()) { tables.addAll(mapping.getDBTables()); @@ -354,7 +353,6 @@ public abstract class AbstractMappingStrategy extends Lifecycle implements IMapp private IClassMapping createClassMapping(EClass eClass) { IClassMapping mapping = doCreateClassMapping(eClass); - if (mapping != null) { classMappings.put(eClass, mapping); @@ -372,16 +370,26 @@ public abstract class AbstractMappingStrategy extends Lifecycle implements IMapp public final IClassMapping getClassMapping(EClass eClass) { + // Try without synchronization first; this will almost always succeed, so it avoids the + // performance penalty of syncing in the majority of cases IClassMapping result = classMappings.get(eClass); - if (result != null) - { - return result; - } - else + if (result == null) { - // create class mapping on demand ... - return createClassMapping(eClass); + // Synchronize on the classMappings to prevent concurrent invocations of createClassMapping + // (Synchronizing on the eClass allows for more concurrency, but is risky because application + // code may be syncing on the eClass also.) + synchronized (classMappings) + { + // Check again, because other thread may have just added the mapping + result = classMappings.get(eClass); + if (result == null) + { + result = createClassMapping(eClass); + } + } } + + return result; } public ITypeMapping createValueMapping(EStructuralFeature feature) |