1/*
2 Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
3
4 This file is part of libzmq, the ZeroMQ core engine in C++.
5
6 libzmq is free software; you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 As a special exception, the Contributors give you permission to link
12 this library with independent modules to produce an executable,
13 regardless of the license terms of these independent modules, and to
14 copy and distribute the resulting executable under terms of your choice,
15 provided that you also meet, for each linked independent module, the
16 terms and conditions of the license of that module. An independent
17 module is a module which is not derived from or based on this library.
18 If you modify this library, you must extend this exception to your
19 version of the library.
20
21 libzmq is distributed in the hope that it will be useful, but WITHOUT
22 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
23 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
24 License for more details.
25
26 You should have received a copy of the GNU Lesser General Public License
27 along with this program. If not, see <http://www.gnu.org/licenses/>.
28*/
29
30#ifndef __ZMQ_MAILBOX_HPP_INCLUDED__
31#define __ZMQ_MAILBOX_HPP_INCLUDED__
32
33#include <stddef.h>
34
35#include "signaler.hpp"
36#include "fd.hpp"
37#include "config.hpp"
38#include "command.hpp"
39#include "ypipe.hpp"
40#include "mutex.hpp"
41#include "i_mailbox.hpp"
42
43namespace zmq
44{
45class mailbox_t : public i_mailbox
46{
47 public:
48 mailbox_t ();
49 ~mailbox_t ();
50
51 fd_t get_fd () const;
52 void send (const command_t &cmd_);
53 int recv (command_t *cmd_, int timeout_);
54
55 bool valid () const;
56
57#ifdef HAVE_FORK
58 // close the file descriptors in the signaller. This is used in a forked
59 // child process to close the file descriptors so that they do not interfere
60 // with the context in the parent process.
61 void forked () { _signaler.forked (); }
62#endif
63
64 private:
65 // The pipe to store actual commands.
66 typedef ypipe_t<command_t, command_pipe_granularity> cpipe_t;
67 cpipe_t _cpipe;
68
69 // Signaler to pass signals from writer thread to reader thread.
70 signaler_t _signaler;
71
72 // There's only one thread receiving from the mailbox, but there
73 // is arbitrary number of threads sending. Given that ypipe requires
74 // synchronised access on both of its endpoints, we have to synchronise
75 // the sending side.
76 mutex_t _sync;
77
78 // True if the underlying pipe is active, ie. when we are allowed to
79 // read commands from it.
80 bool _active;
81
82 ZMQ_NON_COPYABLE_NOR_MOVABLE (mailbox_t)
83};
84}
85
86#endif
87