Interface PooledObject<T>

  • Type Parameters:
    T - the type of object in the pool
    All Superinterfaces:
    java.lang.Comparable<PooledObject<T>>
    All Known Implementing Classes:
    DefaultPooledObject, PooledSoftReference

    public interface PooledObject<T>
    extends java.lang.Comparable<PooledObject<T>>
    Defines the wrapper that is used to track the additional information, such as state, for the pooled objects.

    Implementations of this class are required to be thread-safe.

    Since:
    2.0
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      boolean allocate()
      Allocates the object.
      int compareTo​(PooledObject<T> other)
      Orders instances based on idle time - i.e. the length of time since the instance was returned to the pool.
      boolean deallocate()
      Deallocates the object and sets it IDLE if it is currently ALLOCATED.
      boolean endEvictionTest​(java.util.Deque<PooledObject<T>> idleQueue)
      Called to inform the object that the eviction test has ended.
      boolean equals​(java.lang.Object obj)  
      long getActiveTimeMillis()
      Obtains the time in milliseconds that this object last spent in the active state (it may still be active in which case subsequent calls will return an increased value).
      long getBorrowedCount()
      Gets the number of times this object has been borrowed.
      long getCreateTime()
      Obtains the time (using the same basis as System.currentTimeMillis()) that this object was created.
      long getIdleTimeMillis()
      Obtains the time in milliseconds that this object last spend in the idle state (it may still be idle in which case subsequent calls will return an increased value).
      long getLastBorrowTime()
      Obtains the time the wrapped object was last borrowed.
      long getLastReturnTime()
      Obtains the time the wrapped object was last returned.
      long getLastUsedTime()
      Returns an estimate of the last time this object was used.
      T getObject()
      Obtains the underlying object that is wrapped by this instance of PooledObject.
      PooledObjectState getState()
      Returns the state of this object.
      int hashCode()  
      void invalidate()
      Sets the state to INVALID
      void markAbandoned()
      Marks the pooled object as abandoned.
      void markReturning()
      Marks the object as returning to the pool.
      void printStackTrace​(java.io.PrintWriter writer)
      Prints the stack trace of the code that borrowed this pooled object and the stack trace of the last code to use this object (if available) to the supplied writer.
      void setLogAbandoned​(boolean logAbandoned)
      Is abandoned object tracking being used?
      void setRequireFullStackTrace​(boolean requireFullStackTrace)
      Configures the stack trace generation strategy based on whether or not fully detailed stack traces are required.
      boolean startEvictionTest()
      Attempts to place the pooled object in the PooledObjectState.EVICTION state.
      java.lang.String toString()
      Provides a String form of the wrapper for debug purposes.
      void use()
      Record the current stack trace as the last time the object was used.
    • Method Detail

      • getObject

        T getObject()
        Obtains the underlying object that is wrapped by this instance of PooledObject.
        Returns:
        The wrapped object
      • getCreateTime

        long getCreateTime()
        Obtains the time (using the same basis as System.currentTimeMillis()) that this object was created.
        Returns:
        The creation time for the wrapped object
      • getActiveTimeMillis

        long getActiveTimeMillis()
        Obtains the time in milliseconds that this object last spent in the active state (it may still be active in which case subsequent calls will return an increased value).
        Returns:
        The time in milliseconds last spent in the active state
      • getBorrowedCount

        long getBorrowedCount()
        Gets the number of times this object has been borrowed.
        Returns:
        The number of times this object has been borrowed.
        Since:
        2.7.0
      • getIdleTimeMillis

        long getIdleTimeMillis()
        Obtains the time in milliseconds that this object last spend in the idle state (it may still be idle in which case subsequent calls will return an increased value).
        Returns:
        The time in milliseconds last spent in the idle state
      • getLastBorrowTime

        long getLastBorrowTime()
        Obtains the time the wrapped object was last borrowed.
        Returns:
        The time the object was last borrowed
      • getLastReturnTime

        long getLastReturnTime()
        Obtains the time the wrapped object was last returned.
        Returns:
        The time the object was last returned
      • compareTo

        int compareTo​(PooledObject<T> other)
        Orders instances based on idle time - i.e. the length of time since the instance was returned to the pool. Used by the GKOP idle object evictor.

        Note: This class has a natural ordering that is inconsistent with equals if distinct objects have the same identity hash code.

        Specified by:
        compareTo in interface java.lang.Comparable<T>
      • equals

        boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object
      • hashCode

        int hashCode()
        Overrides:
        hashCode in class java.lang.Object
      • toString

        java.lang.String toString()
        Provides a String form of the wrapper for debug purposes. The format is not fixed and may change at any time.

        Overrides:
        toString in class java.lang.Object
      • endEvictionTest

        boolean endEvictionTest​(java.util.Deque<PooledObject<T>> idleQueue)
        Called to inform the object that the eviction test has ended.
        Parameters:
        idleQueue - The queue of idle objects to which the object should be returned
        Returns:
        Currently not used
      • allocate

        boolean allocate()
        Allocates the object.
        Returns:
        true if the original state was IDLE
      • deallocate

        boolean deallocate()
        Deallocates the object and sets it IDLE if it is currently ALLOCATED.
        Returns:
        true if the state was ALLOCATED
      • invalidate

        void invalidate()
        Sets the state to INVALID
      • setLogAbandoned

        void setLogAbandoned​(boolean logAbandoned)
        Is abandoned object tracking being used? If this is true the implementation will need to record the stack trace of the last caller to borrow this object.
        Parameters:
        logAbandoned - The new configuration setting for abandoned object tracking
      • setRequireFullStackTrace

        void setRequireFullStackTrace​(boolean requireFullStackTrace)
        Configures the stack trace generation strategy based on whether or not fully detailed stack traces are required. When set to false, abandoned logs may only include caller class information rather than method names, line numbers, and other normal metadata available in a full stack trace.
        Parameters:
        requireFullStackTrace - the new configuration setting for abandoned object logging
        Since:
        2.7.0
      • use

        void use()
        Record the current stack trace as the last time the object was used.
      • printStackTrace

        void printStackTrace​(java.io.PrintWriter writer)
        Prints the stack trace of the code that borrowed this pooled object and the stack trace of the last code to use this object (if available) to the supplied writer.
        Parameters:
        writer - The destination for the debug output
      • getState

        PooledObjectState getState()
        Returns the state of this object.
        Returns:
        state
      • markAbandoned

        void markAbandoned()
        Marks the pooled object as abandoned.
      • markReturning

        void markReturning()
        Marks the object as returning to the pool.