diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/SampleDAO.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/SampleDAO.java
index 8544f483fe979cb6fe704f888caaa53ecf932e4d..6d86d2feba237de4be611e3e4e613fe43d56d62b 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/SampleDAO.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/server/dataaccess/db/SampleDAO.java
@@ -37,6 +37,7 @@ import ch.systemsx.cisd.openbis.generic.shared.dto.GroupPE;
import ch.systemsx.cisd.openbis.generic.shared.dto.HierarchyType;
import ch.systemsx.cisd.openbis.generic.shared.dto.SamplePE;
import ch.systemsx.cisd.openbis.generic.shared.dto.SampleTypePE;
+import ch.systemsx.cisd.openbis.generic.shared.dto.TableNames;
/**
* Implementation of {@link ISampleDAO} for databases.
@@ -51,12 +52,14 @@ public class SampleDAO extends AbstractDAO implements ISampleDAO
/**
* This logger does not output any SQL statement. If you want to do so, you had better set an
- * appropriate debugging level for class {@link JdbcAccessor}.
- * </p>
+ * appropriate debugging level for class {@link JdbcAccessor}. </p>
*/
private static final Logger operationLog =
LogFactory.getLogger(LogCategory.OPERATION, SampleDAO.class);
+ private static final String LOCK_TABLE_SQL =
+ "LOCK TABLE " + TableNames.SAMPLES_TABLE + " IN EXCLUSIVE MODE";
+
SampleDAO(final SessionFactory sessionFactory, final DatabaseInstancePE databaseInstance)
{
super(sessionFactory, databaseInstance);
@@ -87,11 +90,29 @@ public class SampleDAO extends AbstractDAO implements ISampleDAO
}
}
+ /**
+ * Obtains an explicit exclusive lock on 'samples' table. This function should always be
+ * executed before saving a sample because we have a complex unique code check in a trigger and
+ * we don't want any race condition or deadlock (if lock is gathered in the trigger). See
+ * [LMS-814] for details.
+ */
+ private final void lockTable()
+ {
+ executeUpdate(LOCK_TABLE_SQL);
+ }
+
+ /**
+ * <b>IMPORTANT</b> - every method which executes this method should first obtain lock on table
+ * using {@link SampleDAO#lockTable()}. The obtained lock is reentrant so this method could as
+ * well obtain it itself with a small additional cost if there are many saves in one
+ * transaction.
+ */
private final void internalCreateSample(final SamplePE sample,
final HibernateTemplate hibernateTemplate)
{
validatePE(sample);
sample.setCode(CodeConverter.tryToDatabase(sample.getCode()));
+
hibernateTemplate.saveOrUpdate(sample);
if (operationLog.isInfoEnabled())
{
@@ -108,6 +129,7 @@ public class SampleDAO extends AbstractDAO implements ISampleDAO
assert sample != null : "Unspecified sample";
final HibernateTemplate hibernateTemplate = getHibernateTemplate();
+ lockTable();
internalCreateSample(sample, hibernateTemplate);
hibernateTemplate.flush();
}
@@ -236,6 +258,7 @@ public class SampleDAO extends AbstractDAO implements ISampleDAO
assert samples != null && samples.size() > 0 : "Unspecified or empty samples.";
final HibernateTemplate hibernateTemplate = getHibernateTemplate();
+ lockTable();
for (final SamplePE samplePE : samples)
{
internalCreateSample(samplePE, hibernateTemplate);
diff --git a/openbis/source/sql/postgresql/031/function-031.sql b/openbis/source/sql/postgresql/031/function-031.sql
index 2d588758fc480517dfd4544a51daab8db1ac198b..518c4ce6e2e1a0bede43b02852f7b7166ed1e607 100644
--- a/openbis/source/sql/postgresql/031/function-031.sql
+++ b/openbis/source/sql/postgresql/031/function-031.sql
@@ -78,6 +78,7 @@ CREATE OR REPLACE FUNCTION SAMPLE_CODE_UNIQUENESS_CHECK() RETURNS trigger AS $$
DECLARE
counter INTEGER;
BEGIN
+ LOCK TABLE samples IN EXCLUSIVE MODE;
IF (NEW.samp_id_part_of is NULL) THEN
IF (NEW.dbin_id is not NULL) THEN
SELECT count(*) into counter FROM samples
diff --git a/openbis/source/sql/postgresql/migration/migration-030-031.sql b/openbis/source/sql/postgresql/migration/migration-030-031.sql
index 2004ec95f62c45089d9f3ebb86f702ce657cbb06..d461bf354581a40a26386fd0a148d774cf3e069c 100644
--- a/openbis/source/sql/postgresql/migration/migration-030-031.sql
+++ b/openbis/source/sql/postgresql/migration/migration-030-031.sql
@@ -100,3 +100,45 @@ insert into data_types
,'MULTILINE_VARCHAR'
,'Long text'
);
+
+-- -------
+-- Added explicit lock Samples table in exclusive mode to prevent race condition
+-- -------
+
+CREATE OR REPLACE FUNCTION SAMPLE_CODE_UNIQUENESS_CHECK() RETURNS trigger AS $$
+DECLARE
+ counter INTEGER;
+BEGIN
+ LOCK TABLE samples IN EXCLUSIVE MODE;
+ IF (NEW.samp_id_part_of is NULL) THEN
+ IF (NEW.dbin_id is not NULL) THEN
+ SELECT count(*) into counter FROM samples
+ where id != NEW.id and code = NEW.code and samp_id_part_of is NULL and dbin_id = NEW.dbin_id;
+ IF (counter > 0) THEN
+ RAISE EXCEPTION 'Insert/Update of Sample (Code: %) failed because database instance sample with the same code already exists.', NEW.code;
+ END IF;
+ ELSIF (NEW.grou_id is not NULL) THEN
+ SELECT count(*) into counter FROM samples
+ where id != NEW.id and code = NEW.code and samp_id_part_of is NULL and grou_id = NEW.grou_id;
+ IF (counter > 0) THEN
+ RAISE EXCEPTION 'Insert/Update of Sample (Code: %) failed because group sample with the same code already exists.', NEW.code;
+ END IF;
+ END IF;
+ ELSE
+ IF (NEW.dbin_id is not NULL) THEN
+ SELECT count(*) into counter FROM samples
+ where id != NEW.id and code = NEW.code and samp_id_part_of = NEW.samp_id_part_of and dbin_id = NEW.dbin_id;
+ IF (counter > 0) THEN
+ RAISE EXCEPTION 'Insert/Update of Sample (Code: %) failed because database instance sample with the same code and being the part of the same parent already exists.', NEW.code;
+ END IF;
+ ELSIF (NEW.grou_id is not NULL) THEN
+ SELECT count(*) into counter FROM samples
+ where id != NEW.id and code = NEW.code and samp_id_part_of = NEW.samp_id_part_of and grou_id = NEW.grou_id;
+ IF (counter > 0) THEN
+ RAISE EXCEPTION 'Insert/Update of Sample (Code: %) failed because group sample with the same code and being the part of the same parent already exists.', NEW.code;
+ END IF;
+ END IF;
+ END IF;
+ RETURN NEW;
+END;
+$$ LANGUAGE 'plpgsql';