summaryrefslogtreecommitdiff
path: root/src/session.cpp
blob: b8577248ab0ca1e079cd28bbbdca3deef59316c3 (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
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
/*
    Copyright (c) 2007-2011 iMatix Corporation
    Copyright (c) 2007-2011 Other contributors as noted in the AUTHORS file

    This file is part of 0MQ.

    0MQ 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.

    0MQ 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 "session.hpp"
#include "socket_base.hpp"
#include "i_engine.hpp"
#include "err.hpp"
#include "pipe.hpp"
#include "likely.hpp"
#include "tcp_connecter.hpp"
#include "vtcp_connecter.hpp"
#include "pgm_sender.hpp"
#include "pgm_receiver.hpp"

zmq::session_t::session_t (class io_thread_t *io_thread_, bool connect_,
      class socket_base_t *socket_, const options_t &options_,
      const char *protocol_, const char *address_) :
    own_t (io_thread_, options_),
    io_object_t (io_thread_),
    connect (connect_),
    pipe (NULL),
    incomplete_in (false),
    pending (false),
    engine (NULL),
    socket (socket_),
    io_thread (io_thread_),
    has_linger_timer (false)
{
    if (protocol_)
        protocol = protocol_;
    if (address_)
        address = address_;
}

zmq::session_t::~session_t ()
{
    zmq_assert (!pipe);

    //  If there's still a pending linger timer, remove it.
    if (has_linger_timer) {
        cancel_timer (linger_timer_id);
        has_linger_timer = false;
    }

    //  Close the engine.
    if (engine)
        engine->terminate ();
}

void zmq::session_t::attach_pipe (pipe_t *pipe_)
{
    zmq_assert (!is_terminating ());
    zmq_assert (!pipe);
    zmq_assert (pipe_);
    pipe = pipe_;
    pipe->set_event_sink (this);
}

bool zmq::session_t::read (msg_t *msg_)
{
    if (!pipe)
        return false;

    if (!pipe->read (msg_))
        return false;

    incomplete_in =
        msg_->flags () & (msg_t::more | msg_t::label) ? true : false;
    return true;
}

bool zmq::session_t::write (msg_t *msg_)
{
    if (pipe && pipe->write (msg_)) {
        int rc = msg_->init ();
        errno_assert (rc == 0);
        return true;
    }

    return false;
}

void zmq::session_t::flush ()
{
    if (pipe)
        pipe->flush ();
}

void zmq::session_t::clean_pipes ()
{
    if (pipe) {

        //  Get rid of half-processed messages in the out pipe. Flush any
        //  unflushed messages upstream.
        pipe->rollback ();
        pipe->flush ();

        //  Remove any half-read message from the in pipe.
        while (incomplete_in) {
            msg_t msg;
            int rc = msg.init ();
            errno_assert (rc == 0);
            if (!read (&msg)) {
                zmq_assert (!incomplete_in);
                break;
            }
            rc = msg.close ();
            errno_assert (rc == 0);
        }
    }
}

void zmq::session_t::terminated (pipe_t *pipe_)
{
    //  Drop the reference to the deallocated pipe.
    zmq_assert (pipe == pipe_);
    pipe = NULL;

    //  If we are waiting for pending messages to be sent, at this point
    //  we are sure that there will be no more messages and we can proceed
    //  with termination safely.
    if (pending)
        proceed_with_term ();
}

void zmq::session_t::read_activated (pipe_t *pipe_)
{
    zmq_assert (pipe == pipe_);

    if (likely (engine != NULL))
        engine->activate_out ();
    else
        pipe->check_read ();
}

void zmq::session_t::write_activated (pipe_t *pipe_)
{
    zmq_assert (pipe == pipe_);

    if (engine)
        engine->activate_in ();
}

void zmq::session_t::hiccuped (pipe_t *pipe_)
{
    //  Hiccups are always sent from session to socket, not the other
    //  way round.
    zmq_assert (false);
}

void zmq::session_t::process_plug ()
{
    if (connect)
        start_connecting (false);
}

void zmq::session_t::process_attach (i_engine *engine_)
{
    //  If some other object (e.g. init) notifies us that the connection failed
    //  without creating an engine we need to start the reconnection process.
    if (!engine_) {
        zmq_assert (!engine);
        detached ();
        return;
    }

    //  Create the pipe if it does not exist yet.
    if (!pipe && !is_terminating ()) {
        object_t *parents [2] = {this, socket};
        pipe_t *pipes [2] = {NULL, NULL};
        int hwms [2] = {options.rcvhwm, options.sndhwm};
        bool delays [2] = {options.delay_on_close, options.delay_on_disconnect};
        int rc = pipepair (parents, pipes, hwms, delays);
        errno_assert (rc == 0);

        //  Plug the local end of the pipe.
        pipes [0]->set_event_sink (this);

        //  Remember the local end of the pipe.
        zmq_assert (!pipe);
        pipe = pipes [0];

        //  Ask socket to plug into the remote end of the pipe.
        send_bind (socket, pipes [1]);
    }

    //  Plug in the engine.
    zmq_assert (!engine);
    engine = engine_;
    engine->plug (io_thread, this);
}

void zmq::session_t::detach ()
{
    //  Engine is dead. Let's forget about it.
    engine = NULL;

    //  Remove any half-done messages from the pipes.
    clean_pipes ();

    //  Send the event to the derived class.
    detached ();

    //  Just in case there's only a delimiter in the pipe.
    if (pipe)
        pipe->check_read ();
}

void zmq::session_t::process_term (int linger_)
{
    zmq_assert (!pending);

    //  If the termination of the pipe happens before the term command is
    //  delivered there's nothing much to do. We can proceed with the
    //  stadard termination immediately.
    if (!pipe) {
        proceed_with_term ();
        return;
    }

    pending = true;

    //  If there's finite linger value, delay the termination.
    //  If linger is infinite (negative) we don't even have to set
    //  the timer.
    if (linger_ > 0) {
        zmq_assert (!has_linger_timer);
        add_timer (linger_, linger_timer_id);
        has_linger_timer = true;
    }

    //  Start pipe termination process. Delay the termination till all messages
    //  are processed in case the linger time is non-zero.
    pipe->terminate (linger_ != 0);

    //  TODO: Should this go into pipe_t::terminate ?
    //  In case there's no engine and there's only delimiter in the
    //  pipe it wouldn't be ever read. Thus we check for it explicitly.
    pipe->check_read ();
}

void zmq::session_t::proceed_with_term ()
{
    //  The pending phase have just ended.
    pending = false;

    //  Continue with standard termination.
    own_t::process_term (0);
}

void zmq::session_t::timer_event (int id_)
{
    //  Linger period expired. We can proceed with termination even though
    //  there are still pending messages to be sent.
    zmq_assert (id_ == linger_timer_id);
    has_linger_timer = false;

    //  Ask pipe to terminate even though there may be pending messages in it.
    zmq_assert (pipe);
    pipe->terminate (false);
}

void zmq::session_t::detached ()
{
    //  Transient session self-destructs after peer disconnects.
    if (!connect) {
        terminate ();
        return;
    }

    //  Reconnect.
    start_connecting (true);

    //  For subscriber sockets we hiccup the inbound pipe, which will cause
    //  the socket object to resend all the subscriptions.
    if (pipe && (options.type == ZMQ_SUB || options.type == ZMQ_XSUB))
        pipe->hiccup ();  
}

void zmq::session_t::start_connecting (bool wait_)
{
    zmq_assert (connect);

    //  Choose I/O thread to run connecter in. Given that we are already
    //  running in an I/O thread, there must be at least one available.
    io_thread_t *io_thread = choose_io_thread (options.affinity);
    zmq_assert (io_thread);

    //  Create the connecter object.

    //  Both TCP and IPC transports are using the same infrastructure.
    if (protocol == "tcp" || protocol == "ipc") {

        tcp_connecter_t *connecter = new (std::nothrow) tcp_connecter_t (
            io_thread, this, options, protocol.c_str (), address.c_str (),
            wait_);
        alloc_assert (connecter);
        launch_child (connecter);
        return;
    }

#if defined ZMQ_HAVE_VTCP
    if (protocol == "vtcp") {

        vtcp_connecter_t *connecter = new (std::nothrow) vtcp_connecter_t (
            io_thread, this, options, address.c_str (),
            wait_);
        alloc_assert (connecter);
        launch_child (connecter);
        return;
    }
#endif

#if defined ZMQ_HAVE_OPENPGM

    //  Both PGM and EPGM transports are using the same infrastructure.
    if (protocol == "pgm" || protocol == "epgm") {

        //  For EPGM transport with UDP encapsulation of PGM is used.
        bool udp_encapsulation = (protocol == "epgm");

        //  At this point we'll create message pipes to the session straight
        //  away. There's no point in delaying it as no concept of 'connect'
        //  exists with PGM anyway.
        if (options.type == ZMQ_PUB || options.type == ZMQ_XPUB) {

            //  PGM sender.
            pgm_sender_t *pgm_sender =  new (std::nothrow) pgm_sender_t (
                io_thread, options);
            alloc_assert (pgm_sender);

            int rc = pgm_sender->init (udp_encapsulation, address.c_str ());
            zmq_assert (rc == 0);

            send_attach (this, pgm_sender);
        }
        else if (options.type == ZMQ_SUB || options.type == ZMQ_XSUB) {

            //  PGM receiver.
            pgm_receiver_t *pgm_receiver =  new (std::nothrow) pgm_receiver_t (
                io_thread, options);
            alloc_assert (pgm_receiver);

            int rc = pgm_receiver->init (udp_encapsulation, address.c_str ());
            zmq_assert (rc == 0);

            send_attach (this, pgm_receiver);
        }
        else
            zmq_assert (false);

        return;
    }
#endif

    zmq_assert (false);
}