Github user marmbrus commented on a diff in the pull request:

    https://github.com/apache/spark/pull/8909#discussion_r41421063
  
    --- Diff: sql/core/src/main/scala/org/apache/spark/sql/SQLContext.scala ---
    @@ -1208,36 +1204,72 @@ object SQLContext {
       private val INSTANTIATION_LOCK = new Object()
     
       /**
    -   * Reference to the last created SQLContext.
    +   * The active SQLContext for threads.
    +   */
    +  private val activeContexts: InheritableThreadLocal[SQLContext] =
    +    new InheritableThreadLocal[SQLContext]
    +
    +  /**
    +   * Reference to the created SQLContext.
        */
    -  @transient private val lastInstantiatedContext = new 
AtomicReference[SQLContext]()
    +  @transient private val instantiatedContext = new 
AtomicReference[SQLContext]()
     
       /**
        * Get the singleton SQLContext if it exists or create a new one using 
the given SparkContext.
    +   *
        * This function can be used to create a singleton SQLContext object 
that can be shared across
        * the JVM.
    +   *
    +   * If there an active SQLContext for current thread, it will returned 
instead of the global one.
        */
       def getOrCreate(sparkContext: SparkContext): SQLContext = {
    +    val ctx = activeContexts.get()
    +    if (ctx != null) {
    +      return ctx
    +    }
    +
         INSTANTIATION_LOCK.synchronized {
    -      if (lastInstantiatedContext.get() == null) {
    +      val ctx = instantiatedContext.get()
    +      if (ctx == null) {
             new SQLContext(sparkContext)
    +      } else {
    +        ctx
           }
         }
    -    lastInstantiatedContext.get()
       }
     
    -  private[sql] def clearLastInstantiatedContext(): Unit = {
    +  private[sql] def clearInstantiatedContext(): Unit = {
    +    INSTANTIATION_LOCK.synchronized {
    +      instantiatedContext.set(null)
    +    }
    +  }
    +
    +  private[sql] def clearTheInstantiatedContext(sqlContext: SQLContext): 
Unit = {
         INSTANTIATION_LOCK.synchronized {
    -      lastInstantiatedContext.set(null)
    +      instantiatedContext.compareAndSet(sqlContext, null)
         }
       }
     
    -  private[sql] def setLastInstantiatedContext(sqlContext: SQLContext): 
Unit = {
    +  private[sql] def setInstantiatedContext(sqlContext: SQLContext): Unit = {
         INSTANTIATION_LOCK.synchronized {
    -      lastInstantiatedContext.set(sqlContext)
    +      instantiatedContext.compareAndSet(null, sqlContext)
         }
       }
     
    +  /*
    --- End diff --
    
    nit: indent and need two *


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org

Reply via email to