summaryrefslogtreecommitdiff
path: root/src/own.cpp
blob: 45f1cbfb680316f52459a68f03bd974f8f49136f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
/*
    Copyright (c) 2010-2012 250bpm s.r.o.
    Copyright (c) 2010-2011 Other contributors as noted in the AUTHORS file

    This file is part of Crossroads I/O project.

    Crossroads I/O is free software; you can redistribute it and/or modify it
    under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    Crossroads is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "own.hpp"
#include "err.hpp"
#include "io_thread.hpp"

xs::own_t::own_t (class ctx_t *parent_, uint32_t tid_) :
    object_t (parent_, tid_),
    terminating (false),
    sent_seqnum (0),
    processed_seqnum (0),
    owner (NULL),
    term_acks (0)
{
}

xs::own_t::own_t (io_thread_t *io_thread_, const options_t &options_) :
    object_t (io_thread_),
    options (options_),
    terminating (false),
    sent_seqnum (0),
    processed_seqnum (0),
    owner (NULL),
    term_acks (0)
{
}

xs::own_t::~own_t ()
{
}

void xs::own_t::set_owner (own_t *owner_)
{
    xs_assert (!owner);
    owner = owner_;
}

void xs::own_t::inc_seqnum ()
{
    //  This function may be called from a different thread!
    sent_seqnum.add (1);
}

void xs::own_t::process_seqnum ()
{
    //  Catch up with counter of processed commands.
    processed_seqnum++;

    //  We may have catched up and still have pending terms acks.
    check_term_acks ();
}

void xs::own_t::launch_child (own_t *object_)
{
    //  Specify the owner of the object.
    object_->set_owner (this);

    //  Plug the object into the I/O thread.
    send_plug (object_);

    //  If the object is already being shut down, new owned objects are
    //  immediately asked to terminate. Note that linger is set to zero.
    if (terminating) {
        register_term_acks (1);
        send_term (object_, 0);
        return;
    }

    //  Store the reference to the owned object.
    owned.insert (object_);
}

void xs::own_t::process_term_req (own_t *object_)
{
    //  When shutting down we can ignore termination requests from owned
    //  objects. The termination request was already sent to the object.
    if (terminating)
        return;

    //  If I/O object is well and alive let's ask it to terminate.
    owned_t::iterator it = std::find (owned.begin (), owned.end (), object_);

    //  If not found, we assume that termination request was already sent to
    //  the object so we can safely ignore the request.
    if (it == owned.end ())
        return;

    owned.erase (it);
    register_term_acks (1);

    //  Note that this object is the root of the (partial shutdown) thus, its
    //  value of linger is used, rather than the value stored by the children.
    send_term (object_, options.linger);
}

void xs::own_t::terminate ()
{
    //  If termination is already underway, there's no point
    //  in starting it anew.
    if (terminating)
        return;

    //  As for the root of the ownership tree, there's noone to terminate it,
    //  so it has to terminate itself.
    if (!owner) {
        process_term (options.linger);
        return;
    }

    //  If I am an owned object, I'll ask my owner to terminate me.
    send_term_req (owner, this);
}

bool xs::own_t::is_terminating ()
{
    return terminating;
}

void xs::own_t::process_term (int linger_)
{
    //  Double termination should never happen.
    xs_assert (!terminating);

    //  Send termination request to all owned objects.
    for (owned_t::iterator it = owned.begin (); it != owned.end (); ++it)
        send_term (*it, linger_);
    register_term_acks ((int) owned.size ());
    owned.clear ();

    //  Start termination process and check whether by chance we cannot
    //  terminate immediately.
    terminating = true;
    check_term_acks ();
}

void xs::own_t::register_term_acks (int count_)
{
    term_acks += count_;
}

void xs::own_t::unregister_term_ack ()
{
    xs_assert (term_acks > 0);
    term_acks--;

    //  This may be a last ack we are waiting for before termination...
    check_term_acks (); 
}

void xs::own_t::process_term_ack ()
{
    unregister_term_ack ();
}

void xs::own_t::check_term_acks ()
{
    if (terminating && processed_seqnum == sent_seqnum.get () &&
          term_acks == 0) {

        //  Sanity check. There should be no active children at this point.
        xs_assert (owned.empty ());

        //  The root object has nobody to confirm the termination to.
        //  Other nodes will confirm the termination to the owner.
        if (owner)
            send_term_ack (owner);

        //  Deallocate the resources.
        process_destroy ();
    }
}

void xs::own_t::process_destroy ()
{
    delete this;
}