Class: Concurrent::Edge::LockFreeStack

Inherits:
Synchronization::Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/concurrent/edge/lock_free_stack.rb

Defined Under Namespace

Classes: Empty, Node

Constant Summary collapse

EMPTY = 
Empty[nil, nil]

Instance Method Summary collapse

Constructor Details

#initialize ⇒ LockFreeStack

Returns a new instance of LockFreeStack.



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 28

def initialize
  super()
  self.head = EMPTY
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 79

def clear
  while true
    current_head = head
    return false if current_head == EMPTY
    return true if compare_and_set_head current_head, EMPTY
  end
end

#clear_each(&block) ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 87

def clear_each(&block)
  while true
    current_head = head
    return self if current_head == EMPTY
    if compare_and_set_head current_head, EMPTY
      each current_head, &block
      return self
    end
  end
end

#compare_and_clear(head) ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 63

def compare_and_clear(head)
  compare_and_set_head head, EMPTY
end

#compare_and_pop(head) ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 52

def compare_and_pop(head)
  compare_and_set_head head, head.next_node
end

#compare_and_push(head, value) ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 37

def compare_and_push(head, value)
  compare_and_set_head head, Node[value, head]
end

#each(head = nil) ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 69

def each(head = nil)
  return to_enum(:each, head) unless block_given?
  it = head || peek
  until it.equal?(EMPTY)
    yield it.value
    it = it.next_node
  end
  self
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/concurrent/edge/lock_free_stack.rb', line 33

def empty?
  head.equal? EMPTY
end

#peek ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 48

def peek
  head
end

#pop ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 56

def pop
  while true
    current_head = head
    return current_head.value if compare_and_set_head current_head, current_head.next_node
  end
end

#push(value) ⇒ Object 



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# File 'lib/concurrent/edge/lock_free_stack.rb', line 41

def push(value)
  while true
    current_head = head
    return self if compare_and_set_head current_head, Node[value, current_head]
  end
end