Byzantine Generals Coding Sample: /home/serif/byzantine_generals/src/orderqueue.h Source File

00001 /**
00002  * @file orderqueue.h
00003  * @author Reshen Amin <reshen@zensrc.com>
00004  *
00005  * @brief Contains the class definition for @ref OrderQueue
00006  *
00007  * @license Byzantine Generals Problem Coding Sample.<br>
00008  * Copyright (C) 2010  Reshen Amin.<br>
00009  * See @ref license_sec for details.<br>
00010  */
00011 
00012 #ifndef SRC_ORDERQUEUE_H_
00013 #define SRC_ORDERQUEUE_H_
00014 
00015 #include <boost/interprocess/sync/interprocess_mutex.hpp>
00016 #include <boost/interprocess/sync/interprocess_semaphore.hpp>
00017 
00018 #include "order.h"
00019 
00020 /**
00021  * @brief  A FIFO Data Structure (Queue) which we specialize to store
00022  * Orders.
00023  */
00024 class OrderQueue {
00025     public:
00026         /**
00027          * @brief  Constructor
00028          *
00029          * @param order_alloc Shared Memory Allocator from which Orders are
00030          * allocated
00031          */
00032         explicit OrderQueue(const OrderAllocator &order_alloc);
00033 
00034         /**
00035          * @brief  Destructor
00036          */
00037         ~OrderQueue();
00038 
00039         /**
00040          * @brief  Insert the provided order at the end of the queue.  This
00041          * operation is thread safe and will block until it can be completed.
00042          *
00043          * @param ord Order to insert
00044          */
00045         void PushBack(const Order& ord);
00046 
00047         /**
00048          * @brief  Remove and return the front @ref Order of the queue.  This
00049          * operation is thread safe and will block until it can be completed
00050          * (if there are no orders in the queue, this operation will pend
00051          * until one becomes available).
00052          *
00053          * @return  The front @ref Order in the queue
00054          */
00055         Order PopFront();
00056 
00057         /**
00058          * @brief  Check if the queue is empty.
00059          *
00060          * @return  TRUE if the Queue is empty (size 0), FALSE otherwise.
00061          */
00062         bool Empty();
00063 
00064     private:
00065         /**
00066          * @brief  Underlying non-thread-safe container used to store the Orders
00067          */
00068         OrderList order_list_;
00069 
00070         /**
00071          * @brief  Mutex used to allow thread-safe access to the underlying
00072          * @ref order_list_
00073          */
00074         boost::interprocess::interprocess_mutex mutex_;
00075 
00076         /**
00077          * @brief  Semaphore used to track the size of the queue.  The
00078          * semaphore is incremented on calls to @ref PushBack and decremented
00079          * on calls to @ref PopFront
00080          */
00081         boost::interprocess::interprocess_semaphore sem_fill_;
00082 };
00083 
00084 #endif  // SRC_ORDERQUEUE_H_