Add caching of resolved relations in SnappySessionCatalog

Sumedh Wale · Sumedh Wale · commit 8b43301cc944 · 2021-10-01T14:47:43.000+05:30
- resolving relations especially for cases like external file-based tables having large
  number of partitions can take a long time due to meta-data gather/process, so added a
  cache for resolved relations in SnappySessionCatalog
- invalidate this cache whenever ExternalCatalog is being invalidated; in addition check for
  whether the CatalogTable looked up from ExternalCatalog matches the one cached previously
  and if not then invalidate and re-fetch -- this handles cases where table got invalidated
  from another session
- also add invalidation for the case of inserts into hadoop/hive tables since that will
  result in new files not present in meta-data and can also result in creation of new
  partitions
- added a dunit test to check the above i.e. correct results after adding new
  data/partitions from a different session
diff --git a/aqp b/aqp
@@ -1 +1 @@
-Subproject commit 1c05060ebca9e2ec3773190d5b7fd8c988c1b21a
+Subproject commit 08d73fb23c77484e1163bdcde7948d95108ef594
diff --git a/cluster/src/dunit/scala/org/apache/spark/sql/ColumnBatchAndExternalTableDUnitTest.scala b/cluster/src/dunit/scala/org/apache/spark/sql/ColumnBatchAndExternalTableDUnitTest.scala
@@ -17,11 +17,14 @@
 package org.apache.spark.sql
 
 
+import java.io.File
+
 import com.pivotal.gemfirexd.internal.engine.Misc
 import io.snappydata.Property
 import io.snappydata.cluster.ClusterManagerTestBase
 import io.snappydata.test.dunit.{AvailablePortHelper, SerializableCallable}
 import io.snappydata.util.TestUtils
+import org.apache.commons.io.FileUtils
 import org.scalatest.Assertions
 
 import org.apache.spark.internal.Logging
@@ -411,6 +414,54 @@ class ColumnBatchAndExternalTableDUnitTest(s: String) extends ClusterManagerTest
     assert(expected - max <= TestUtils.defaultCores,
       s"Lower limit of concurrent tasks = $expected, actual = $max")
   }
+
+  def testExternalTableMetadataCacheWithInserts(): Unit = {
+    val dataDir = new File("extern1")
+    FileUtils.deleteQuietly(dataDir)
+    dataDir.mkdir()
+    // create external parquet table and insert some data
+    val session = new SnappySession(sc)
+    session.sql("create table extern1 (id long, data string, stat string) using parquet " +
+        s"options (path '${dataDir.getAbsolutePath}') partitioned by (stat)")
+    session.sql("insert into extern1 select id, 'data_' || id, 'stat' || (id % 10) " +
+        "from range(100000)")
+
+    // check results
+    assert(session.sql("select * from extern1 where stat = 'stat1'").collect().length === 10000)
+    assert(session.sql("select * from extern1 where stat = 'stat2'").collect().length === 10000)
+
+    // insert more data from another session
+    val session2 = new SnappySession(sc)
+    session2.sql("insert into extern1 select id, 'data_' || id, 'stat' || (id % 10) " +
+        "from range(10000)")
+
+    // check results
+    assert(session.sql("select * from extern1 where stat = 'stat1'").collect().length === 11000)
+    assert(session.sql("select * from extern1 where stat = 'stat2'").collect().length === 11000)
+    assert(session.sql("select * from extern1 where stat = 'stat3'").collect().length === 11000)
+    assert(session.sql("select * from extern1 where stat = 'stat11'").collect().length === 0)
+
+    // insert more data with new partitions
+    session2.sql("insert into extern1 select id, 'data_' || id, 'stat' || (id % 20) " +
+        "from range(10000)")
+
+    // check results
+    assert(session.sql("select * from extern1 where stat = 'stat1'").collect().length === 11500)
+    assert(session.sql("select * from extern1 where stat = 'stat2'").collect().length === 11500)
+    assert(session.sql("select * from extern1 where stat = 'stat3'").collect().length === 11500)
+    assert(session.sql("select * from extern1 where stat = 'stat11'").collect().length === 500)
+
+    assert(session2.sql("select * from extern1 where stat = 'stat1'").collect().length === 11500)
+    assert(session2.sql("select * from extern1 where stat = 'stat2'").collect().length === 11500)
+    assert(session2.sql("select * from extern1 where stat = 'stat3'").collect().length === 11500)
+    assert(session2.sql("select * from extern1 where stat = 'stat11'").collect().length === 500)
+
+    session.sql("drop table extern1")
+    session.clear()
+    session2.clear()
+
+    FileUtils.deleteDirectory(dataDir)
+  }
 }
 
 case class AirlineData(year: Int, month: Int, dayOfMonth: Int,
diff --git a/cluster/src/dunit/scala/org/apache/spark/sql/SmartConnectorFunctions.scala b/cluster/src/dunit/scala/org/apache/spark/sql/SmartConnectorFunctions.scala
@@ -76,7 +76,7 @@ object SmartConnectorFunctions {
 
     val sc = SparkContext.getOrCreate(conf)
     val snc = SnappyContext(sc)
-    snc.snappySession.externalCatalog.invalidateAll()
+    snc.snappySession.sessionCatalog.invalidateAll()
     val sqlContext = new SparkSession(sc).sqlContext
     val pw = new PrintWriter(new FileOutputStream(
       new File(s"ValidateNWQueries_$tableType.out"), true))
diff --git a/cluster/src/main/scala/org/apache/spark/memory/SnappyUnifiedMemoryManager.scala b/cluster/src/main/scala/org/apache/spark/memory/SnappyUnifiedMemoryManager.scala
@@ -793,9 +793,10 @@ class SnappyUnifiedMemoryManager private[memory](
       numBytes: Long,
       memoryMode: MemoryMode): Unit = {
     // if UMM lock is already held, then release inline else enqueue and be done with it
-    if (Thread.holdsLock(this) || !pendingStorageMemoryReleases.offer(
-      (objectName, numBytes, memoryMode), 15, TimeUnit.SECONDS)) {
-      synchronized(releaseStorageMemoryForObject_(objectName, numBytes, memoryMode))
+    if (Thread.holdsLock(this)) synchronized {
+      releaseStorageMemoryForObject_(objectName, numBytes, memoryMode)
+    } else {
+      pendingStorageMemoryReleases.put((objectName, numBytes, memoryMode))
     }
   }
 
diff --git a/cluster/src/test/scala/org/apache/spark/sql/execution/SnappyTableMutableAPISuite.scala b/cluster/src/test/scala/org/apache/spark/sql/execution/SnappyTableMutableAPISuite.scala
@@ -824,7 +824,8 @@ class SnappyTableMutableAPISuite extends SnappyFunSuite with Logging with Before
     val message = intercept[AnalysisException] {
       df2.write.deleteFrom("col_table")
     }.getMessage
-    assert(message.contains("column `pk3` cannot be resolved on the right side of the operation."))
+    assert(message.contains("column `pk3` cannot be resolved on the right side of the operation.")
+        || message.contains("WHERE clause of the DELETE FROM statement must have all the key"))
   }
 
   test("Bug - SNAP-2157") {
@@ -908,7 +909,8 @@ class SnappyTableMutableAPISuite extends SnappyFunSuite with Logging with Before
     }.getMessage
 
     assert(message.contains("DeleteFrom operation requires " +
-        "key columns(s) or primary key defined on table."))
+        "key columns(s) or primary key defined on table.") ||
+        message.contains("WHERE clause of the DELETE FROM statement must have all the key"))
   }
 
 
@@ -930,7 +932,8 @@ class SnappyTableMutableAPISuite extends SnappyFunSuite with Logging with Before
       df2.write.deleteFrom("row_table")
     }.getMessage
 
-    assert(message.contains("column `pk3` cannot be resolved on the right side of the operation."))
+    assert(message.contains("column `pk3` cannot be resolved on the right side of the operation.")
+        || message.contains("WHERE clause of the DELETE FROM statement must have all the key"))
   }
 
   test("Delete From SQL using JDBC: row tables") {
diff --git a/compatibilityTests/src/test/scala/org/apache/spark/sql/hive/TestHiveSnappySession.scala b/compatibilityTests/src/test/scala/org/apache/spark/sql/hive/TestHiveSnappySession.scala
@@ -72,7 +72,7 @@ class TestHiveSnappySession(@transient protected val sc: SparkContext,
       sharedState.cacheManager.clearCache()
       loadedTables.clear()
       sessionCatalog.clearTempTables()
-      sessionCatalog.externalCatalog.invalidateAll()
+      sessionCatalog.invalidateAll()
 
       FunctionRegistry.getFunctionNames.asScala.filterNot(originalUDFs.contains(_)).
           foreach { udfName => FunctionRegistry.unregisterTemporaryUDF(udfName) }
diff --git a/core/src/main/scala/io/snappydata/Literals.scala b/core/src/main/scala/io/snappydata/Literals.scala
@@ -168,9 +168,9 @@ object Property extends Enumeration {
         "(value in bytes or k/m/g suffixes for unit, min 1k). Default is 4MB.", Some("4m"))
 
   val ResultPersistenceTimeout: SparkValue[Long] = Val[Long](
-    s"${Constant.SPARK_PREFIX}sql.ResultPersistenceTimeout",
+    s"${Constant.SPARK_PREFIX}sql.resultPersistenceTimeout",
     s"Maximum duration in seconds for which results larger than ${MaxMemoryResultSize.name}" +
-        s"are held on disk after which they are cleaned up. Default is 3600s (1h).", Some(3600L))
+        s"are held on disk after which they are cleaned up. Default is 7200 (2h).", Some(7200L))
 
   val DisableHashJoin: SQLValue[Boolean] = SQLVal[Boolean](
     s"${Constant.PROPERTY_PREFIX}sql.disableHashJoin",
diff --git a/core/src/main/scala/org/apache/spark/sql/CachedDataFrame.scala b/core/src/main/scala/org/apache/spark/sql/CachedDataFrame.scala
@@ -415,7 +415,7 @@ class CachedDataFrame(snappySession: SnappySession, queryExecution: QueryExecuti
             } catch {
               case t: Throwable
                 if CachedDataFrame.isConnectorCatalogStaleException(t, snappySession) =>
-                snappySession.externalCatalog.invalidateAll()
+                snappySession.sessionCatalog.invalidateAll()
                 SnappySession.clearAllCache()
                 val execution =
                   snappySession.getContextObject[() => QueryExecution](SnappySession.ExecutionKey)
@@ -1005,7 +1005,7 @@ object CachedDataFrame
       } catch {
         case t: Throwable
           if CachedDataFrame.isConnectorCatalogStaleException(t, snappySession) =>
-          snappySession.externalCatalog.invalidateAll()
+          snappySession.sessionCatalog.invalidateAll()
           SnappySession.clearAllCache()
           if (attempts < retryCount) {
             Thread.sleep(attempts*100)
diff --git a/core/src/main/scala/org/apache/spark/sql/SnappySession.scala b/core/src/main/scala/org/apache/spark/sql/SnappySession.scala
@@ -245,12 +245,11 @@ class SnappySession(_sc: SparkContext) extends SparkSession(_sc) {
             val relations = plan.collect {
               case _: Command => hasCommand = true; null
               case u: UnresolvedRelation =>
-                val tableIdent = sessionCatalog.resolveTableIdentifier(u.tableIdentifier)
-                tableIdent.database.get -> tableIdent.table
+                sessionCatalog.resolveTableIdentifier(u.tableIdentifier)
             }
-            if (hasCommand) externalCatalog.invalidateAll()
+            if (hasCommand) sessionCatalog.invalidateAll()
             else if (relations.nonEmpty) {
-              relations.foreach(externalCatalog.invalidate)
+              relations.foreach(sessionCatalog.invalidate(_))
             }
             throw e
           case _ =>
@@ -332,6 +331,7 @@ class SnappySession(_sc: SparkContext) extends SparkSession(_sc) {
   @transient
   private var sqlWarnings: SQLWarning = _
 
+  private[sql] var catalogInitialized: Boolean = _
   private[sql] var hiveInitializing: Boolean = _
 
   private[sql] def isHiveSupportEnabled(v: String): Boolean = Utils.toLowerCase(v) match {
@@ -1700,6 +1700,7 @@ class SnappySession(_sc: SparkContext) extends SparkSession(_sc) {
     plan match {
       case LogicalRelation(rls: RowLevelSecurityRelation, _, _) =>
         rls.enableOrDisableRowLevelSecurity(tableIdent, enableRls)
+        sessionCatalog.invalidate(tableIdent)
         externalCatalog.invalidateCaches(tableIdent.database.get -> tableIdent.table :: Nil)
       case _ =>
         throw new AnalysisException("ALTER TABLE enable/disable Row Level Security " +
diff --git a/core/src/main/scala/org/apache/spark/sql/execution/CodegenSparkFallback.scala b/core/src/main/scala/org/apache/spark/sql/execution/CodegenSparkFallback.scala
@@ -110,7 +110,7 @@ case class CodegenSparkFallback(var child: SparkPlan,
                 result
               } catch {
                 case t: Throwable if CachedDataFrame.isConnectorCatalogStaleException(t, session) =>
-                  session.externalCatalog.invalidateAll()
+                  session.sessionCatalog.invalidateAll()
                   SnappySession.clearAllCache()
                   throw CachedDataFrame.catalogStaleFailure(t, session)
               } finally {
@@ -125,7 +125,7 @@ case class CodegenSparkFallback(var child: SparkPlan,
   }
 
   private def handleStaleCatalogException[T](f: SparkPlan => T, plan: SparkPlan, t: Throwable) = {
-    session.externalCatalog.invalidateAll()
+    session.sessionCatalog.invalidateAll()
     SnappySession.clearAllCache()
     // fail immediate for insert/update/delete, else retry entire query
     val action = plan.find {
diff --git a/core/src/main/scala/org/apache/spark/sql/execution/columnar/impl/ColumnFormatRelation.scala b/core/src/main/scala/org/apache/spark/sql/execution/columnar/impl/ColumnFormatRelation.scala
@@ -436,7 +436,7 @@ abstract class BaseColumnFormatRelation(
     createExternalTableForColumnBatches(externalColumnTableName, conn)
     // store schema will miss complex types etc, so use the user-provided one
     val session = sqlContext.sparkSession.asInstanceOf[SnappySession]
-    session.externalCatalog.invalidate(schemaName -> tableName)
+    session.sessionCatalog.invalidate(TableIdentifier(tableName, Some(schemaName)))
     _schema = userSchema
     _relationInfoAndRegion = null
   }
diff --git a/core/src/main/scala/org/apache/spark/sql/hive/SnappySessionState.scala b/core/src/main/scala/org/apache/spark/sql/hive/SnappySessionState.scala
@@ -674,14 +674,16 @@ class SnappySessionState(val snappySession: SnappySession)
    * Internal catalog for managing table and database states.
    */
   override lazy val catalog: SnappySessionCatalog = {
-    new SnappySessionCatalog(
+    val sessionCatalog = new SnappySessionCatalog(
       snappySession.sharedState.getExternalCatalogInstance(snappySession),
       snappySession,
       snappySession.sharedState.globalTempViewManager,
       functionResourceLoader,
       functionRegistry,
       conf,
       newHadoopConf())
+    snappySession.catalogInitialized = true
+    sessionCatalog
   }
 
   protected lazy val wrapperCatalog: SessionCatalogWrapper = {
@@ -701,7 +703,7 @@ class SnappySessionState(val snappySession: SnappySession)
     python.ExtractPythonUDFs,
     TokenizeSubqueries(snappySession),
     EnsureRequirements(conf),
-    OptimizeSortAndFilePlans(conf),
+    OptimizeSortAndFilePlans(snappySession),
     CollapseCollocatedPlans(snappySession),
     CollapseCodegenStages(conf),
     InsertCachedPlanFallback(snappySession, topLevel),
@@ -916,14 +918,28 @@ class SnappyAnalyzer(sessionState: SnappySessionState)
  * Rule to replace Spark's SortExec plans with an optimized SnappySortExec (in SMJ for now).
  * Also sets the "spark.task.cpus" property implicitly for file scans/writes.
  */
-case class OptimizeSortAndFilePlans(conf: SnappyConf) extends Rule[SparkPlan] {
+case class OptimizeSortAndFilePlans(session: SnappySession) extends Rule[SparkPlan] {
   override def apply(plan: SparkPlan): SparkPlan = plan.transformUp {
     case join@joins.SortMergeJoinExec(_, _, _, _, _, sort@SortExec(_, _, child, _)) =>
       join.copy(right = SnappySortExec(sort, child))
-    case s@(_: FileSourceScanExec | _: HiveTableScanExec | _: InsertIntoHiveTable |
+    case i: InsertIntoHiveTable =>
+      val table = i.table.catalogTable
+      // invalidate meta-data since that can change after the insert
+      val tableIdentifier = session.sessionCatalog.resolveTableIdentifier(table.identifier)
+      session.externalCatalog.invalidate(tableIdentifier.database.get -> tableIdentifier.table)
+      session.sessionState.conf.setDynamicCpusPerTask()
+      i
+    case c@ExecutedCommandExec(i: InsertIntoHadoopFsRelationCommand) if i.catalogTable.isDefined =>
+      val table = i.catalogTable.get
+      // invalidate meta-data since that can change after the insert
+      val tableIdentifier = session.sessionCatalog.resolveTableIdentifier(table.identifier)
+      session.externalCatalog.invalidate(tableIdentifier.database.get -> tableIdentifier.table)
+      session.sessionState.conf.setDynamicCpusPerTask()
+      c
+    case s@(_: FileSourceScanExec | _: HiveTableScanExec |
             ExecutedCommandExec(_: InsertIntoHadoopFsRelationCommand |
                                 _: CreateHiveTableAsSelectCommand)) =>
-      conf.setDynamicCpusPerTask()
+      session.sessionState.conf.setDynamicCpusPerTask()
       s
   }
 }
diff --git a/core/src/main/scala/org/apache/spark/sql/internal/ColumnTableBulkOps.scala b/core/src/main/scala/org/apache/spark/sql/internal/ColumnTableBulkOps.scala
@@ -121,7 +121,7 @@ object ColumnTableBulkOps {
           result
         } catch {
           case t: Throwable if CachedDataFrame.isConnectorCatalogStaleException(t, session) =>
-            session.externalCatalog.invalidateAll()
+            session.sessionCatalog.invalidateAll()
             SnappySession.clearAllCache()
             // throw failure immediately to keep it consistent with insert/update/delete
             throw CachedDataFrame.catalogStaleFailure(t, session)
diff --git a/core/src/main/scala/org/apache/spark/sql/internal/SnappySessionCatalog.scala b/core/src/main/scala/org/apache/spark/sql/internal/SnappySessionCatalog.scala
@@ -23,12 +23,13 @@ import java.sql.SQLException
 import scala.util.control.NonFatal
 
 import com.gemstone.gemfire.SystemFailure
+import com.google.common.cache.{CacheBuilder, CacheLoader, LoadingCache}
 import com.pivotal.gemfirexd.Attribute
 import com.pivotal.gemfirexd.internal.iapi.util.IdUtil
 import io.snappydata.Constant
 import io.snappydata.sql.catalog.CatalogObjectType.getTableType
 import io.snappydata.sql.catalog.SnappyExternalCatalog.{DBTABLE_PROPERTY, getTableWithSchema}
-import io.snappydata.sql.catalog.{CatalogObjectType, SnappyExternalCatalog}
+import io.snappydata.sql.catalog.{CatalogObjectType, ConnectorExternalCatalog, SnappyExternalCatalog}
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.Path
 
@@ -96,6 +97,19 @@ class SnappySessionCatalog(val externalCatalog: SnappyExternalCatalog,
     defaultName
   }
 
+  /** A cache of Spark SQL data source tables that have been accessed. */
+  // noinspection UnstableApiUsage
+  protected[sql] val cachedDataSourceTables: LoadingCache[TableIdentifier, LogicalPlan] = {
+    val loader = new CacheLoader[TableIdentifier, LogicalPlan]() {
+      override def load(tableName: TableIdentifier): LogicalPlan = {
+        logDebug(s"Creating new cached data source for $tableName")
+        val table = externalCatalog.getTable(tableName.database.get, tableName.table)
+        new FindDataSourceTable(snappySession)(SimpleCatalogRelation(table.database, table))
+      }
+    }
+    CacheBuilder.newBuilder().maximumSize(ConnectorExternalCatalog.cacheSize >> 2).build(loader)
+  }
+
   final def getCurrentSchema: String = getCurrentDatabase
 
   /**
@@ -270,7 +284,11 @@ class SnappySessionCatalog(val externalCatalog: SnappyExternalCatalog,
   final def resolveRelationWithAlias(tableIdent: TableIdentifier,
       alias: Option[String] = None): LogicalPlan = {
     // resolve the relation right away with alias around
-    new FindDataSourceTable(snappySession)(lookupRelation(tableIdent, alias))
+    lookupRelation(tableIdent, alias) match {
+      case lr: LogicalRelation => lr
+      case a: SubqueryAlias if a.child.isInstanceOf[LogicalRelation] => a
+      case r => new FindDataSourceTable(snappySession)(r)
+    }
   }
 
   /**
@@ -878,7 +896,17 @@ class SnappySessionCatalog(val externalCatalog: SnappyExternalCatalog,
               getPolicyPlan(table)
             } else {
               view = None
-              SimpleCatalogRelation(schemaName, table)
+              if (DDLUtils.isDatasourceTable(table)) {
+                val resolved = TableIdentifier(tableName, Some(schemaName))
+                cachedDataSourceTables(resolved) match {
+                  case lr: LogicalRelation
+                    if lr.catalogTable.isDefined && (lr.catalogTable.get ne table) =>
+                    // refresh since table metadata has changed
+                    cachedDataSourceTables.invalidate(resolved)
+                    cachedDataSourceTables(resolved)
+                  case p => p
+                }
+              } else SimpleCatalogRelation(schemaName, table)
             }
           }
         case Some(p) => p
@@ -914,13 +942,23 @@ class SnappySessionCatalog(val externalCatalog: SnappyExternalCatalog,
       super.refreshTable(table)
     } else {
       val resolved = resolveTableIdentifier(table)
-      externalCatalog.invalidate(resolved.database.get -> resolved.table)
+      invalidate(resolved)
       if (snappySession.enableHiveSupport) {
         hiveSessionCatalog.refreshTable(resolved)
       }
     }
   }
 
+  def invalidate(resolved: TableIdentifier, sessionOnly: Boolean = false): Unit = {
+    cachedDataSourceTables.invalidate(resolved)
+    if (!sessionOnly) externalCatalog.invalidate(resolved.database.get -> resolved.table)
+  }
+
+  def invalidateAll(sessionOnly: Boolean = false): Unit = {
+    cachedDataSourceTables.invalidateAll()
+    if (!sessionOnly) externalCatalog.invalidateAll()
+  }
+
   def getDataSourceRelations[T](tableType: CatalogObjectType.Type): Seq[T] = {
     externalCatalog.getAllTables().collect {
       case table if tableType == CatalogObjectType.getTableType(table) =>
diff --git a/core/src/main/scala/org/apache/spark/sql/internal/session.scala b/core/src/main/scala/org/apache/spark/sql/internal/session.scala
@@ -239,7 +239,9 @@ class SnappyConf(@transient val session: SnappySession)
         key
     }
 
-    case GAttr.USERNAME_ATTR | GAttr.USERNAME_ALT_ATTR | GAttr.PASSWORD_ATTR => key
+    case GAttr.USERNAME_ATTR | GAttr.USERNAME_ALT_ATTR | GAttr.PASSWORD_ATTR =>
+      if (session.catalogInitialized) session.sessionCatalog.invalidateAll(sessionOnly = true)
+      key
 
     case _ if key.startsWith("spark.sql.aqp.") =>
       session.clearPlanCache()
diff --git a/core/src/main/scala/org/apache/spark/sql/sources/interfaces.scala b/core/src/main/scala/org/apache/spark/sql/sources/interfaces.scala
diff --git a/core/src/test/scala/io/snappydata/ColumnUpdateDeleteTests.scala b/core/src/test/scala/io/snappydata/ColumnUpdateDeleteTests.scala
diff --git a/core/src/test/scala/org/apache/spark/sql/streaming/SnappyStoreSinkProviderSecuritySuite.scala b/core/src/test/scala/org/apache/spark/sql/streaming/SnappyStoreSinkProviderSecuritySuite.scala

Original file line number	Diff line number	Diff line change
`@@ -793,9 +793,10 @@ class SnappyUnifiedMemoryManager private[memory](`
`793`	`793`	`numBytes: Long,`
`794`	`794`	`memoryMode: MemoryMode): Unit = {`
`795`	`795`	`// if UMM lock is already held, then release inline else enqueue and be done with it`
`796`		`- if (Thread.holdsLock(this) \|\| !pendingStorageMemoryReleases.offer(`
`797`		`- (objectName, numBytes, memoryMode), 15, TimeUnit.SECONDS)) {`
`798`		`- synchronized(releaseStorageMemoryForObject_(objectName, numBytes, memoryMode))`
	`796`	`+ if (Thread.holdsLock(this)) synchronized {`
	`797`	`+ releaseStorageMemoryForObject_(objectName, numBytes, memoryMode)`
	`798`	`+ } else {`
	`799`	`+ pendingStorageMemoryReleases.put((objectName, numBytes, memoryMode))`
`799`	`800`	`}`
`800`	`801`	`}`
`801`	`802`