src/dataqueue.h

   1 ///
   2 /// \file       dataqueue.h
   3 ///             FIFO queue of Data objects
   4 ///
   5
   6 /*
   7     Copyright (C) 2007-2013, Net Direct Inc. (http://www.netdirect.ca/)
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17
  18     See the GNU General Public License in the COPYING file at the
  19     root directory of this project for more details.
  20 */
  21
  22 #ifndef __BARRY_DATAQUEUE_H__
  23 #define __BARRY_DATAQUEUE_H__
  24
  25 #include "dll.h"
  26 #include <list>
  27 #include <pthread.h>
  28 #include <iosfwd>
  29
  30 namespace Barry {
  31
  32 class Data;
  33
  34 //
  35 // DataQueue class
  36 //
  37 /// This class provides a thread aware fifo queue for Data objects,
  38 /// providing memory management for all Data object pointers it contains.
  39 ///
  40 /// It uses similar member names as std::queue<>, for consistency.
  41 ///
  42 class BXEXPORT DataQueue
  43 {
  44         // always use the raw_push() and raw_pop() functions
  45         typedef std::list<Data*>                        queue_type;
  46
  47         pthread_mutex_t m_waitMutex;
  48         pthread_cond_t m_waitCond;
  49
  50         mutable pthread_mutex_t m_accessMutex;  // locked for each access of m_queue
  51
  52         queue_type m_queue;
  53
  54 protected:
  55         void raw_push(Data *data);
  56         Data* raw_pop();
  57
  58 public:
  59         DataQueue();
  60         ~DataQueue();           // frees all data in the queue
  61
  62         // Pushes data into the end of the queue.
  63         // The queue owns this pointer as soon as the function is
  64         // called.  In the case of an exception, it will be freed.
  65         // Performs a thread broadcast once new data has been added.
  66         void push(Data *data);
  67
  68         // Pops the next element off the front of the queue.
  69         // Returns 0 if empty.
  70         // The queue no longer owns this pointer upon return.
  71         Data* pop();
  72
  73         // Pops the next element off the front of the queue, and
  74         // waits until one exists if empty.  If still no data
  75         // on timeout, returns null.
  76         // Timeout specified in milliseconds.  Default is wait forever.
  77         Data* wait_pop(int timeout = -1);
  78
  79         // Pops all data from other and appends it to this.
  80         // After calling this function, other will be empty, and
  81         // this will contain all its data.
  82         // In the case of an exception, any uncopied data will
  83         // remain in other.
  84         void append_from(DataQueue &other);
  85
  86         bool empty() const;     // return true if empty
  87         size_t size() const;
  88
  89         void DumpAll(std::ostream &os) const;
  90 };
  91
  92 inline std::ostream& operator<< (std::ostream &os, const DataQueue &dq)
  93 {
  94         dq.DumpAll(os);
  95         return os;
  96 }
  97
  98 } // namespace Barry
  99
 100 #endif
 101