GNU Radio C++ API
msg_queue.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2009 Free Software Foundation, Inc.
4  *
5  * This file is part of GNU Radio
6  *
7  * GNU Radio is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 3, or (at your option)
10  * any later version.
11  *
12  * GNU Radio is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with GNU Radio; see the file COPYING. If not, write to
19  * the Free Software Foundation, Inc., 51 Franklin Street,
20  * Boston, MA 02110-1301, USA.
21  */
22 #ifndef INCLUDED_MSG_QUEUE_H
23 #define INCLUDED_MSG_QUEUE_H
24 
25 #include <gruel/api.h>
26 #include <gruel/thread.h>
27 #include <gruel/pmt.h>
28 #include <deque>
29 
30 namespace gruel {
31 
32  class msg_queue;
33  typedef boost::shared_ptr<msg_queue> msg_queue_sptr;
34 
35  msg_queue_sptr make_msg_queue(unsigned int limit=0);
36 
37  /*!
38  * \brief thread-safe message queue
39  */
41 
42  gruel::mutex d_mutex;
43  gruel::condition_variable d_not_empty;
44  gruel::condition_variable d_not_full;
45  unsigned int d_limit; // max # of messages in queue. 0 -> unbounded
46 
47  std::deque<pmt::pmt_t> d_msgs;
48 
49  public:
50  msg_queue(unsigned int limit);
51  ~msg_queue();
52 
53  /*!
54  * \brief Insert message at tail of queue.
55  * \param msg message
56  *
57  * Block if queue if full.
58  */
59  void insert_tail(pmt::pmt_t msg);
60 
61  /*!
62  * \brief Delete message from head of queue and return it.
63  * Block if no message is available.
64  */
65  pmt::pmt_t delete_head();
66 
67  /*!
68  * \brief If there's a message in the q, delete it and return it.
69  * If no message is available, return pmt_t().
70  */
71  pmt::pmt_t delete_head_nowait();
72 
73  //! Delete all messages from the queue
74  void flush();
75 
76  //! is the queue empty?
77  bool empty_p() const { return d_msgs.empty(); }
78 
79  //! is the queue full?
80  bool full_p() const { return d_limit != 0 && count() >= d_limit; }
81 
82  //! return number of messages in queue
83  unsigned int count() const { return d_msgs.size(); }
84 
85  //! return limit on number of message in queue. 0 -> unbounded
86  unsigned int limit() const { return d_limit; }
87  };
88 
89 } /* namespace gruel */
90 
91 #endif /* INCLUDED_MSG_QUEUE_H */