TAO/tao/CSD_ThreadPool/CSD_TP_Queue.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    CSD_TP_Queue.h
   6  *
   7  *  @author  Tim Bradley <bradley_t@ociweb.com>
   8  */
   9 //=============================================================================
  10
  11 #ifndef TAO_CSD_TP_QUEUE_H
  12 #define TAO_CSD_TP_QUEUE_H
  13
  14 #include /**/ "ace/pre.h"
  15
  16 #include "tao/CSD_ThreadPool/CSD_TP_Export.h"
  17
  18 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  19 # pragma once
  20 #endif /* ACE_LACKS_PRAGMA_ONCE */
  21
  22 #include "tao/Versioned_Namespace.h"
  23 #include "tao/orbconf.h"
  24
  25 TAO_BEGIN_VERSIONED_NAMESPACE_DECL
  26
  27 namespace TAO
  28 {
  29   namespace CSD
  30   {
  31     class TP_Request;
  32     class TP_Queue_Visitor;
  33
  34     /**
  35      * @class TP_Queue
  36      *
  37      * @brief Queue of servant requests that need to be dispatched.
  38      *
  39      * This is the queue of pending servant requests that is "owned"
  40      * by a TP_Strategy object.  When an ORB thread dispatches
  41      * a servant request to the strategy object, it will create the
  42      * appropriate (subclass of) TP_Request object to "wrap"
  43      * the servant request in a "queue-friendly" wrapper.  The ORB thread
  44      * will then place the TP_Request object on to the queue.  Note that
  45      * this scenario pertains to what are being called "remote requests".
  46      * There are other scenarios in which other types of requests can
  47      * get added to this queue.
  48      *
  49      * The strategy object will employ a set of worker threads that are
  50      * responsible for "servicing" the servant requests in the queue.
  51      *
  52      * Note: In the future, support will be added to allow the client
  53      *       application inject "custom" TP_Request objects into
  54      *       a TP_Strategy object, causing them to be placed in
  55      *       the queue.
  56      */
  57     class TAO_CSD_TP_Export TP_Queue
  58     {
  59     public:
  60       /// Default Constructor.
  61       TP_Queue();
  62
  63       /// Destructor.
  64       ~TP_Queue();
  65
  66       /// Place a request at the end of the queue.
  67       void put(TP_Request* request);
  68
  69       /// Returns true if the queue is empty.  Returns false otherwise.
  70       bool is_empty() const;
  71
  72       /// Visitors will visit each request in the queue, from front to back,
  73       /// and have the ability to stop visiting at any time (ie, before
  74       /// visiting every request).
  75       void accept_visitor(TP_Queue_Visitor& visitor);
  76
  77     private:
  78       /// The request at the front of the queue.
  79       TP_Request* head_;
  80
  81       /// The request at the end of the queue.
  82       TP_Request* tail_;
  83     };
  84   }
  85 }
  86
  87 TAO_END_VERSIONED_NAMESPACE_DECL
  88
  89 #if defined (__ACE_INLINE__)
  90 # include "tao/CSD_ThreadPool/CSD_TP_Queue.inl"
  91 #endif /* __ACE_INLINE__ */
  92
  93 #include /**/ "ace/post.h"
  94
  95 #endif /* TAO_CSD_TP_QUEUE_H */