Annotated Ada Reference Manual — Legal Information

A.18.29 The Generic Package Containers.Bounded_Synchronized_Queues

Static Semantics

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{AI05-0159-1} The language-defined generic package Containers.Bounded_Synchronized_Queues provides type Queue, which implements the interface type Containers.Synchronized_Queue_Interfaces.Queue.

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with System;
with Ada.Containers.Synchronized_Queue_Interfaces;
generic
   with package Queue_Interfaces is new Ada.Containers.Synchronized_Queue_Interfaces (<>);
   Default_Capacity : Count_Type;
   Default_Ceiling  : System.Any_Priority := System.Priority'Last;
package Ada.Containers.Bounded_Synchronized_Queues is
   pragma Preelaborate(Bounded_Synchronized_Queues);

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   package Implementation is
      ... -- not specified by the language
   end Implementation;

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   protected type Queue
        (Capacity : Count_Type := Default_Capacity;
         Ceiling: System.Any_Priority := Default_Ceiling)
           with Priority => Ceiling is
        new Queue_Interfaces.Queue with

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      overriding
      entry Enqueue (New_Item : in Queue_Interfaces.Element_Type);
      overriding
      entry Dequeue (Element : out Queue_Interfaces.Element_Type);

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      overriding
      function Current_Use return Count_Type;
      overriding
      function Peak_Use return Count_Type;

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   private
      ... -- not specified by the language
   end Queue;

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private

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... -- not specified by the language

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end Ada.Containers.Bounded_Synchronized_Queues;

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{AI05-0159-1} The semantics are the same as for Unbounded_Synchronized_Queues, except:

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The capacity for instances of type Queue is bounded and specified by the discriminant Capacity.

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Ramification: Since this type has a bounded capacity, Enqueue might block if the queue is full.

Implementation Advice

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{AI05-0159-1} Bounded queue objects should be implemented without implicit pointers or dynamic allocation.

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Implementation Advice: Bounded queue objects should be implemented without implicit pointers or dynamic allocation.

Extensions to Ada 2005

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{AI05-0159-1} The generic package Containers.Bounded_Synchronized_Queues is new.

Ada 2005 and 2012 Editions sponsored in part by Ada-Europe