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#include "precompiled.hpp"
31#include "poll.hpp"
32#if defined ZMQ_IOTHREAD_POLLER_USE_POLL
33
34#include <sys/types.h>
35#include <sys/time.h>
36#include <poll.h>
37#include <algorithm>
38
39#include "poll.hpp"
40#include "err.hpp"
41#include "config.hpp"
42#include "i_poll_events.hpp"
43
44zmq::poll_t::poll_t (const zmq::thread_ctx_t &ctx_) :
45 worker_poller_base_t (ctx_),
46 retired (false)
47{
48}
49
50zmq::poll_t::~poll_t ()
51{
52 stop_worker ();
53}
54
55zmq::poll_t::handle_t zmq::poll_t::add_fd (fd_t fd_, i_poll_events *events_)
56{
57 check_thread ();
58 zmq_assert (fd_ != retired_fd);
59
60 // If the file descriptor table is too small expand it.
61 fd_table_t::size_type sz = fd_table.size ();
62 if (sz <= (fd_table_t::size_type) fd_) {
63 fd_table.resize (fd_ + 1);
64 while (sz != (fd_table_t::size_type) (fd_ + 1)) {
65 fd_table[sz].index = retired_fd;
66 ++sz;
67 }
68 }
69
70 pollfd pfd = {fd_, 0, 0};
71 pollset.push_back (pfd);
72 zmq_assert (fd_table[fd_].index == retired_fd);
73
74 fd_table[fd_].index = pollset.size () - 1;
75 fd_table[fd_].events = events_;
76
77 // Increase the load metric of the thread.
78 adjust_load (1);
79
80 return fd_;
81}
82
83void zmq::poll_t::rm_fd (handle_t handle_)
84{
85 check_thread ();
86 fd_t index = fd_table[handle_].index;
87 zmq_assert (index != retired_fd);
88
89 // Mark the fd as unused.
90 pollset[index].fd = retired_fd;
91 fd_table[handle_].index = retired_fd;
92 retired = true;
93
94 // Decrease the load metric of the thread.
95 adjust_load (-1);
96}
97
98void zmq::poll_t::set_pollin (handle_t handle_)
99{
100 check_thread ();
101 fd_t index = fd_table[handle_].index;
102 pollset[index].events |= POLLIN;
103}
104
105void zmq::poll_t::reset_pollin (handle_t handle_)
106{
107 check_thread ();
108 fd_t index = fd_table[handle_].index;
109 pollset[index].events &= ~((short) POLLIN);
110}
111
112void zmq::poll_t::set_pollout (handle_t handle_)
113{
114 check_thread ();
115 fd_t index = fd_table[handle_].index;
116 pollset[index].events |= POLLOUT;
117}
118
119void zmq::poll_t::reset_pollout (handle_t handle_)
120{
121 check_thread ();
122 fd_t index = fd_table[handle_].index;
123 pollset[index].events &= ~((short) POLLOUT);
124}
125
126void zmq::poll_t::stop ()
127{
128 check_thread ();
129 // no-op... thread is stopped when no more fds or timers are registered
130}
131
132int zmq::poll_t::max_fds ()
133{
134 return -1;
135}
136
137void zmq::poll_t::loop ()
138{
139 while (true) {
140 // Execute any due timers.
141 int timeout = (int) execute_timers ();
142
143 cleanup_retired ();
144
145 if (pollset.empty ()) {
146 zmq_assert (get_load () == 0);
147
148 if (timeout == 0)
149 break;
150
151 // TODO sleep for timeout
152 continue;
153 }
154
155 // Wait for events.
156 int rc = poll (&pollset[0], static_cast<nfds_t> (pollset.size ()),
157 timeout ? timeout : -1);
158 if (rc == -1) {
159 errno_assert (errno == EINTR);
160 continue;
161 }
162
163 // If there are no events (i.e. it's a timeout) there's no point
164 // in checking the pollset.
165 if (rc == 0)
166 continue;
167
168 for (pollset_t::size_type i = 0; i != pollset.size (); i++) {
169 zmq_assert (!(pollset[i].revents & POLLNVAL));
170 if (pollset[i].fd == retired_fd)
171 continue;
172 if (pollset[i].revents & (POLLERR | POLLHUP))
173 fd_table[pollset[i].fd].events->in_event ();
174 if (pollset[i].fd == retired_fd)
175 continue;
176 if (pollset[i].revents & POLLOUT)
177 fd_table[pollset[i].fd].events->out_event ();
178 if (pollset[i].fd == retired_fd)
179 continue;
180 if (pollset[i].revents & POLLIN)
181 fd_table[pollset[i].fd].events->in_event ();
182 }
183 }
184}
185
186void zmq::poll_t::cleanup_retired ()
187{
188 // Clean up the pollset and update the fd_table accordingly.
189 if (retired) {
190 pollset_t::size_type i = 0;
191 while (i < pollset.size ()) {
192 if (pollset[i].fd == retired_fd)
193 pollset.erase (pollset.begin () + i);
194 else {
195 fd_table[pollset[i].fd].index = i;
196 i++;
197 }
198 }
199 retired = false;
200 }
201}
202
203
204#endif
205