Class SynchronizedStack<T>

java.lang.Object
org.apache.tomcat.util.collections.SynchronizedStack<T>
Type Parameters:
T - The type of object managed by this stack
Direct Known Subclasses:
AbstractProtocol.RecycledProcessors
public class SynchronizedStack<T> extends Object
This is intended as a (mostly) GC-free alternative to Stack when the requirement is to create a pool of re-usable objects with no requirement to shrink the pool. The aim is to provide the bare minimum of required functionality as quickly as possible with minimum garbage.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    DEFAULT_SIZE
    The default initial capacity for a new stack.

  • Constructor Summary

    Constructors
    Constructor
    Description
    SynchronizedStack()
    Constructs a new SynchronizedStack with default size and no limit.
    SynchronizedStack(int size, int limit)
    Constructs a new SynchronizedStack with the specified initial size and limit.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Clears all objects from the stack.
    T
    pop()
    Pops an object from the stack.
    boolean
    push(T obj)
    Pushes an object onto the stack.
    void
    setLimit(int limit)
    Sets the maximum number of elements that can be pushed onto this stack.

    Methods inherited from class Object

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

  • Field Details

    • DEFAULT_SIZE

      public static final int DEFAULT_SIZE
      The default initial capacity for a new stack.
      See Also:

  • Constructor Details

    • SynchronizedStack

      public SynchronizedStack()
      Constructs a new SynchronizedStack with default size and no limit.

    • SynchronizedStack

      public SynchronizedStack(int size, int limit)
      Constructs a new SynchronizedStack with the specified initial size and limit.
      Parameters:
      size - the initial capacity
      limit - the maximum capacity, or -1 for unlimited

  • Method Details

    • push

      public boolean push(T obj)
      Pushes an object onto the stack.
      Parameters:
      obj - The object to push
      Returns:
      true if the object was pushed, false if the stack is full

    • pop

      public T pop()
      Pops an object from the stack.
      Returns:
      the object at the top of the stack, or null if the stack is empty

    • clear

      public void clear()
      Clears all objects from the stack.

    • setLimit

      public void setLimit(int limit)
      Sets the maximum number of elements that can be pushed onto this stack. If the new limit is lower than the current capacity, the stack is shrunk. When the stack already holds more elements than the new limit, the most recently pushed elements are retained and the remaining elements are discarded.
      Parameters:
      limit - the maximum size, or -1 for unlimited