Package org.apache.tomcat.util.collections

Class SynchronizedStack<T>

  • Type Parameters:
    T - The type of object managed by this stack
    Direct Known Subclasses:
    AbstractProtocol.RecycledProcessors
    public class SynchronizedStack<T>
extends java.lang.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 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

      All Methods Instance Methods Concrete Methods 
      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 java.lang.Object

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

    • Field Detail

      • DEFAULT_SIZE

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

    • Constructor Detail

      • 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 Detail

      • 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.
        Parameters:
        limit - the maximum size, or -1 for unlimited