Enum Class BlockingDuration

java.lang.Object
java.lang.Enum<BlockingDuration>
org.hibernate.dialect.lock.spi.BlockingDuration
All Implemented Interfaces:
Serializable, Comparable<BlockingDuration>, Constable
public enum BlockingDuration extends Enum<BlockingDuration>

Describes how long protection acquired by one operation on a row prevents a conflicting operation in another transaction from accessing that row. Used by TransactionConcurrency.getBlockingDuration(Operation, Operation) to describe database behavior for an ordered pair of operations.

The duration is in relation to the statement or transaction performing the preceding operation. It does not measure how long the concurrent operation actually waits, and does not require either operation to be executing when this information is requested.

For example, TRANSACTION for a shared-lock read followed by a write means that, once the read acquires its protection, a writer in another transaction cannot modify the row until the reading transaction ends. Reversing the operations asks a separate question: how long a write prevents a shared-lock read in another transaction.

A conflicting operation might fail immediately with NOWAIT, time out, become a deadlock victim, or skip the row with SKIP LOCKED. These outcomes do not change the lifetime of the protection. Conversely, a serialization failure does not by itself imply blocking.

These values describe row protection within the scope of TransactionConcurrency. They exclude incidental internal waits and assume no explicit early release of protection or rollback to a savepoint.

Since:
8.0
See Also:

  • Nested Class Summary

    Nested classes/interfaces inherited from class Enum

    Enum.EnumDesc<E>

  • Enum Constant Summary

    Enum Constants
    Enum Constant
    Description
    CONDITIONAL
    Blocking behavior is known to depend on circumstances that this descriptor does not capture.
    NONE
    The preceding operation does not establish row protection that excludes the concurrent operation.
    STATEMENT
    The preceding operation can exclude the concurrent operation while its statement executes.
    TRANSACTION
    Once acquired, protection established by the preceding operation excludes the concurrent operation until the preceding operation's transaction commits or rolls back.
    UNKNOWN
    Blocking behavior has not been established for this pair of operations.

  • Method Summary

    Modifier and Type
    Method
    Description
    static BlockingDuration
    valueOf(String name)
    Returns the enum constant of this class with the specified name.
    static BlockingDuration[]
    values()
    Returns an array containing the constants of this enum class, in the order they are declared.

    Methods inherited from class Enum

    clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

    Methods inherited from class Object

    getClass, notify, notifyAll, wait, wait, wait

  • Enum Constant Details

    • NONE

      public static final BlockingDuration NONE
      The preceding operation does not establish row protection that excludes the concurrent operation. This does not guarantee that the concurrent operation will complete immediately or successfully, or that a read will observe the latest committed state.

    • STATEMENT

      public static final BlockingDuration STATEMENT
      The preceding operation can exclude the concurrent operation while its statement executes. Protection may be released before that statement completes; this value provides no guarantee of protection after completion.

    • TRANSACTION

      public static final BlockingDuration TRANSACTION
      Once acquired, protection established by the preceding operation excludes the concurrent operation until the preceding operation's transaction commits or rolls back. Protection survives completion of the statement.

    • CONDITIONAL

      public static final BlockingDuration CONDITIONAL
      Blocking behavior is known to depend on circumstances that this descriptor does not capture. No particular duration of protection may be assumed from this value.

    • UNKNOWN

      public static final BlockingDuration UNKNOWN
      Blocking behavior has not been established for this pair of operations. This expresses missing knowledge, whereas CONDITIONAL expresses a known dependency on additional circumstances. Neither value establishes a guarantee of protection or absence of blocking.

  • Method Details

    • values

      public static BlockingDuration[] values()
      Returns an array containing the constants of this enum class, in the order they are declared.
      Returns:
      an array containing the constants of this enum class, in the order they are declared

    • valueOf

      public static BlockingDuration valueOf(String name)
      Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum class has no constant with the specified name
      NullPointerException - if the argument is null