summaryrefslogtreecommitdiff
path: root/src/signaler.cpp
blob: aac3e7ce146b10f46566be84921bab1aabb7caa2 (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
/*
    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 "platform.hpp"

#if defined ZMQ_FORCE_SELECT
#define ZMQ_SIGNALER_WAIT_BASED_ON_SELECT
#elif defined ZMQ_FORCE_POLL
#define ZMQ_SIGNALER_WAIT_BASED_ON_POLL
#elif defined ZMQ_HAVE_LINUX || defined ZMQ_HAVE_FREEBSD ||\
    defined ZMQ_HAVE_OPENBSD || defined ZMQ_HAVE_SOLARIS ||\
    defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_QNXNTO ||\
    defined ZMQ_HAVE_HPUX || defined ZMQ_HAVE_AIX ||\
    defined ZMQ_HAVE_NETBSD
#define ZMQ_SIGNALER_WAIT_BASED_ON_POLL
#elif defined ZMQ_HAVE_WINDOWS || defined ZMQ_HAVE_OPENVMS ||\
	defined ZMQ_HAVE_CYGWIN
#define ZMQ_SIGNALER_WAIT_BASED_ON_SELECT
#endif

//  On AIX, poll.h has to be included before zmq.h to get consistent
//  definition of pollfd structure (AIX uses 'reqevents' and 'retnevents'
//  instead of 'events' and 'revents' and defines macros to map from POSIX-y
//  names to AIX-specific names).
#if defined ZMQ_SIGNALER_WAIT_BASED_ON_POLL
#include <poll.h>
#elif defined ZMQ_SIGNALER_WAIT_BASED_ON_SELECT
#if defined ZMQ_HAVE_WINDOWS
#include "windows.hpp"
#elif defined ZMQ_HAVE_HPUX
#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#elif defined ZMQ_HAVE_OPENVMS
#include <sys/types.h>
#include <sys/time.h>
#else
#include <sys/select.h>
#endif
#endif

#include "signaler.hpp"
#include "likely.hpp"
#include "stdint.hpp"
#include "err.hpp"
#include "fd.hpp"
#include "ip.hpp"

#if defined ZMQ_HAVE_EVENTFD
#include <sys/eventfd.h>
#endif

#if defined ZMQ_HAVE_WINDOWS
#include "windows.hpp"
#else
#include <unistd.h>
#include <netinet/tcp.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#endif

zmq::signaler_t::signaler_t ()
{
    //  Create the socketpair for signaling.
    int rc = make_fdpair (&r, &w);
    errno_assert (rc == 0);

    //  Set both fds to non-blocking mode.
    unblock_socket (w);
    unblock_socket (r);
}

zmq::signaler_t::~signaler_t ()
{
#if defined ZMQ_HAVE_EVENTFD
    int rc = close (r);
    errno_assert (rc == 0);
#elif defined ZMQ_HAVE_WINDOWS
    int rc = closesocket (w);
    wsa_assert (rc != SOCKET_ERROR);
    rc = closesocket (r);
    wsa_assert (rc != SOCKET_ERROR);
#else
    int rc = close (w);
    errno_assert (rc == 0);
    rc = close (r);
    errno_assert (rc == 0);
#endif
}

zmq::fd_t zmq::signaler_t::get_fd ()
{
    return r;
}

void zmq::signaler_t::send ()
{
#if defined ZMQ_HAVE_EVENTFD
    const uint64_t inc = 1;
    ssize_t sz = write (w, &inc, sizeof (inc));
    errno_assert (sz == sizeof (inc));
#elif defined ZMQ_HAVE_WINDOWS
    unsigned char dummy = 0;
    int nbytes = ::send (w, (char*) &dummy, sizeof (dummy), 0);
    wsa_assert (nbytes != SOCKET_ERROR);
    zmq_assert (nbytes == sizeof (dummy));
#else
    unsigned char dummy = 0;
    while (true) {
        ssize_t nbytes = ::send (w, &dummy, sizeof (dummy), 0);
        if (unlikely (nbytes == -1 && errno == EINTR))
            continue;
        zmq_assert (nbytes == sizeof (dummy));
        break;
    }
#endif
}

int zmq::signaler_t::wait (int timeout_)
{
#ifdef ZMQ_SIGNALER_WAIT_BASED_ON_POLL

    struct pollfd pfd;
    pfd.fd = r;
    pfd.events = POLLIN;
    int rc = poll (&pfd, 1, timeout_);
    if (unlikely (rc < 0)) {
        zmq_assert (errno == EINTR);
        return -1;
    }
    else if (unlikely (rc == 0)) {
        errno = EAGAIN;
        return -1;
    }
    zmq_assert (rc == 1);
    zmq_assert (pfd.revents & POLLIN);
    return 0;

#elif defined ZMQ_SIGNALER_WAIT_BASED_ON_SELECT

    fd_set fds;
    FD_ZERO (&fds);
    FD_SET (r, &fds);
    struct timeval timeout;
    if (timeout_ >= 0) {
        timeout.tv_sec = timeout_ / 1000;
        timeout.tv_usec = timeout_ % 1000 * 1000;
    }
#ifdef ZMQ_HAVE_WINDOWS
    int rc = select (0, &fds, NULL, NULL,
        timeout_ >= 0 ? &timeout : NULL);
    wsa_assert (rc != SOCKET_ERROR);
#else
    int rc = select (r + 1, &fds, NULL, NULL,
        timeout_ >= 0 ? &timeout : NULL);
    if (unlikely (rc < 0)) {
        zmq_assert (errno == EINTR);
        return -1;
    }
#endif
    if (unlikely (rc == 0)) {
        errno = EAGAIN;
        return -1;
    }
    zmq_assert (rc == 1);
    return 0;

#else
#error
#endif
}

void zmq::signaler_t::recv ()
{
    //  Attempt to read a signal.
#if defined ZMQ_HAVE_EVENTFD
    uint64_t dummy;
    ssize_t sz = read (r, &dummy, sizeof (dummy));
    errno_assert (sz == sizeof (dummy));

    //  If we accidentally grabbed the next signal along with the current
    //  one, return it back to the eventfd object.
    if (unlikely (dummy == 2)) {
        const uint64_t inc = 1;
        ssize_t sz = write (w, &inc, sizeof (inc));
        errno_assert (sz == sizeof (inc));
        return;
    }

    zmq_assert (dummy == 1);
#else
    unsigned char dummy;
#if defined ZMQ_HAVE_WINDOWS
    int nbytes = ::recv (r, (char*) &dummy, sizeof (dummy), 0);
    wsa_assert (nbytes != SOCKET_ERROR);
#else
    ssize_t nbytes = ::recv (r, &dummy, sizeof (dummy), 0);
    errno_assert (nbytes >= 0);
#endif
    zmq_assert (nbytes == sizeof (dummy));
    zmq_assert (dummy == 0);
#endif
}

int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
{
#if defined ZMQ_HAVE_EVENTFD

    // Create eventfd object.
    fd_t fd = eventfd (0, 0);
    errno_assert (fd != -1);
    *w_ = fd;
    *r_ = fd;
    return 0;

#elif defined ZMQ_HAVE_WINDOWS

    //  Windows has no 'socketpair' function. CreatePipe is no good as pipe
    //  handles cannot be polled on. Here we create the socketpair by hand.
    *w_ = INVALID_SOCKET;
    *r_ = INVALID_SOCKET;

    //  Create listening socket.
    SOCKET listener;
    listener = open_socket (AF_INET, SOCK_STREAM, 0);
    wsa_assert (listener != INVALID_SOCKET);

    //  Set SO_REUSEADDR and TCP_NODELAY on listening socket.
    BOOL so_reuseaddr = 1;
    int rc = setsockopt (listener, SOL_SOCKET, SO_REUSEADDR,
        (char *)&so_reuseaddr, sizeof (so_reuseaddr));
    wsa_assert (rc != SOCKET_ERROR);
    BOOL tcp_nodelay = 1;
    rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELAY,
        (char *)&tcp_nodelay, sizeof (tcp_nodelay));
    wsa_assert (rc != SOCKET_ERROR);

    //  Bind listening socket to any free local port.
    struct sockaddr_in addr;
    memset (&addr, 0, sizeof (addr));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
    addr.sin_port = 0;
    rc = bind (listener, (const struct sockaddr*) &addr, sizeof (addr));
    wsa_assert (rc != SOCKET_ERROR);

    //  Retrieve local port listener is bound to (into addr).
    int addrlen = sizeof (addr);
    rc = getsockname (listener, (struct sockaddr*) &addr, &addrlen);
    wsa_assert (rc != SOCKET_ERROR);

    //  Listen for incomming connections.
    rc = listen (listener, 1);
    wsa_assert (rc != SOCKET_ERROR);

    //  Create the writer socket.
    *w_ = WSASocket (AF_INET, SOCK_STREAM, 0, NULL, 0,  0);
    wsa_assert (*w_ != INVALID_SOCKET);

    //  Set TCP_NODELAY on writer socket.
    rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY,
        (char *)&tcp_nodelay, sizeof (tcp_nodelay));
    wsa_assert (rc != SOCKET_ERROR);

    //  Connect writer to the listener.
    rc = connect (*w_, (sockaddr *) &addr, sizeof (addr));
    wsa_assert (rc != SOCKET_ERROR);

    //  Accept connection from writer.
    *r_ = accept (listener, NULL, NULL);
    wsa_assert (*r_ != INVALID_SOCKET);

    //  We don't need the listening socket anymore. Close it.
    rc = closesocket (listener);
    wsa_assert (rc != SOCKET_ERROR);

    return 0;

#elif defined ZMQ_HAVE_OPENVMS

    //  Whilst OpenVMS supports socketpair - it maps to AF_INET only.  Further,
    //  it does not set the socket options TCP_NODELAY and TCP_NODELACK which
    //  can lead to performance problems.
    //
    //  The bug will be fixed in V5.6 ECO4 and beyond.  In the meantime, we'll
    //  create the socket pair manually.
    sockaddr_in lcladdr;
    memset (&lcladdr, 0, sizeof (lcladdr));
    lcladdr.sin_family = AF_INET;
    lcladdr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
    lcladdr.sin_port = 0;

    int listener = open_socket (AF_INET, SOCK_STREAM, 0);
    errno_assert (listener != -1);

    int on = 1;
    int rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on));
    errno_assert (rc != -1);

    rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELACK, &on, sizeof (on));
    errno_assert (rc != -1);

    rc = bind(listener, (struct sockaddr*) &lcladdr, sizeof (lcladdr));
    errno_assert (rc != -1);

    socklen_t lcladdr_len = sizeof (lcladdr);

    rc = getsockname (listener, (struct sockaddr*) &lcladdr, &lcladdr_len);
    errno_assert (rc != -1);

    rc = listen (listener, 1);
    errno_assert (rc != -1);

    *w_ = open_socket (AF_INET, SOCK_STREAM, 0);
    errno_assert (*w_ != -1);

    rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on));
    errno_assert (rc != -1);

    rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELACK, &on, sizeof (on));
    errno_assert (rc != -1);

    rc = connect (*w_, (struct sockaddr*) &lcladdr, sizeof (lcladdr));
    errno_assert (rc != -1);

    *r_ = accept (listener, NULL, NULL);
    errno_assert (*r_ != -1);

    close (listener);

    return 0;

#else // All other implementations support socketpair()

    int sv [2];
    int rc = socketpair (AF_UNIX, SOCK_STREAM, 0, sv);
    errno_assert (rc == 0);
    *w_ = sv [0];
    *r_ = sv [1];
    return 0;

#endif
}

#if defined ZMQ_SIGNALER_WAIT_BASED_ON_SELECT
#undef ZMQ_SIGNALER_WAIT_BASED_ON_SELECT
#endif
#if defined ZMQ_SIGNALER_WAIT_BASED_ON_POLL
#undef ZMQ_SIGNALER_WAIT_BASED_ON_POLL
#endif