Package org.springframework.util

Class ConcurrencyThrottleSupport

java.lang.Object
org.springframework.util.ConcurrencyThrottleSupport
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
ConcurrencyThrottleInterceptor
public abstract class ConcurrencyThrottleSupport extends Object implements Serializable
Support class for throttling concurrent access to a specific resource.

Designed for use as a base class, with the subclass invoking the beforeAccess() and afterAccess() methods at appropriate points of its workflow. Note that afterAccess should usually be called in a finally block!

The default concurrency limit of this support class is -1 ("unbounded concurrency"). Subclasses may override this default; check the javadoc of the concrete class that you're using.

Since:
1.2.5
Author:
Juergen Hoeller
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected org.apache.commons.logging.Log
    logger
    Transient to optimize serialization.
    static final int
    NO_CONCURRENCY
    Switch concurrency 'off': that is, don't allow any concurrent invocations.
    static final int
    UNBOUNDED_CONCURRENCY
    Permit any number of concurrent invocations: that is, don't throttle concurrency.

  • Constructor Summary

    Constructors
    Constructor
    Description
    ConcurrencyThrottleSupport()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    protected void
    afterAccess()
    To be invoked after the main execution logic of concrete subclasses.
    protected void
    beforeAccess()
    To be invoked before the main execution logic of concrete subclasses.
    int
    getConcurrencyLimit()
    Return the maximum number of concurrent access attempts allowed.
    boolean
    isThrottleActive()
    Return whether this throttle is currently active.
    void
    setConcurrencyLimit(int concurrencyLimit)
    Set the maximum number of concurrent access attempts allowed.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • UNBOUNDED_CONCURRENCY

      public static final int UNBOUNDED_CONCURRENCY
      Permit any number of concurrent invocations: that is, don't throttle concurrency.
      See Also:

    • NO_CONCURRENCY

      public static final int NO_CONCURRENCY
      Switch concurrency 'off': that is, don't allow any concurrent invocations.
      See Also:

    • logger

      protected transient org.apache.commons.logging.Log logger
      Transient to optimize serialization.

  • Constructor Details

    • ConcurrencyThrottleSupport

      public ConcurrencyThrottleSupport()

  • Method Details

    • setConcurrencyLimit

      public void setConcurrencyLimit(int concurrencyLimit)
      Set the maximum number of concurrent access attempts allowed. The default of -1 indicates no concurrency limit at all.

      In principle, this limit can be changed at runtime, although it is generally designed as a config time setting.

      NOTE: Do not switch between -1 and any concrete limit at runtime, as this will lead to inconsistent concurrency counts: A limit of -1 effectively turns off concurrency counting completely.

    • getConcurrencyLimit

      public int getConcurrencyLimit()
      Return the maximum number of concurrent access attempts allowed.

    • isThrottleActive

      public boolean isThrottleActive()
      Return whether this throttle is currently active.
      Returns:
      true if the concurrency limit for this instance is active
      See Also:

    • beforeAccess

      protected void beforeAccess()
      To be invoked before the main execution logic of concrete subclasses.

      This implementation applies the concurrency throttle.

      See Also:

    • afterAccess

      protected void afterAccess()
      To be invoked after the main execution logic of concrete subclasses.
      See Also: