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#if defined ZMQ_IOTHREAD_POLLER_USE_EPOLL
32#include "epoll.hpp"
33
34#if !defined ZMQ_HAVE_WINDOWS
35#include <unistd.h>
36#endif
37
38#include <stdlib.h>
39#include <string.h>
40#include <signal.h>
41#include <algorithm>
42#include <new>
43
44#include "macros.hpp"
45#include "err.hpp"
46#include "config.hpp"
47#include "i_poll_events.hpp"
48
49#ifdef ZMQ_HAVE_WINDOWS
50const zmq::epoll_t::epoll_fd_t zmq::epoll_t::epoll_retired_fd =
51 INVALID_HANDLE_VALUE;
52#endif
53
54zmq::epoll_t::epoll_t (const zmq::thread_ctx_t &ctx_) :
55 worker_poller_base_t (ctx_)
56{
57#ifdef ZMQ_IOTHREAD_POLLER_USE_EPOLL_CLOEXEC
58 // Setting this option result in sane behaviour when exec() functions
59 // are used. Old sockets are closed and don't block TCP ports, avoid
60 // leaks, etc.
61 _epoll_fd = epoll_create1 (EPOLL_CLOEXEC);
62#else
63 _epoll_fd = epoll_create (1);
64#endif
65 errno_assert (_epoll_fd != epoll_retired_fd);
66}
67
68zmq::epoll_t::~epoll_t ()
69{
70 // Wait till the worker thread exits.
71 stop_worker ();
72
73#ifdef ZMQ_HAVE_WINDOWS
74 epoll_close (_epoll_fd);
75#else
76 close (_epoll_fd);
77#endif
78 for (retired_t::iterator it = _retired.begin (), end = _retired.end ();
79 it != end; ++it) {
80 LIBZMQ_DELETE (*it);
81 }
82}
83
84zmq::epoll_t::handle_t zmq::epoll_t::add_fd (fd_t fd_, i_poll_events *events_)
85{
86 check_thread ();
87 poll_entry_t *pe = new (std::nothrow) poll_entry_t;
88 alloc_assert (pe);
89
90 // The memset is not actually needed. It's here to prevent debugging
91 // tools to complain about using uninitialised memory.
92 memset (pe, 0, sizeof (poll_entry_t));
93
94 pe->fd = fd_;
95 pe->ev.events = 0;
96 pe->ev.data.ptr = pe;
97 pe->events = events_;
98
99 int rc = epoll_ctl (_epoll_fd, EPOLL_CTL_ADD, fd_, &pe->ev);
100 errno_assert (rc != -1);
101
102 // Increase the load metric of the thread.
103 adjust_load (1);
104
105 return pe;
106}
107
108void zmq::epoll_t::rm_fd (handle_t handle_)
109{
110 check_thread ();
111 poll_entry_t *pe = static_cast<poll_entry_t *> (handle_);
112 int rc = epoll_ctl (_epoll_fd, EPOLL_CTL_DEL, pe->fd, &pe->ev);
113 errno_assert (rc != -1);
114 pe->fd = retired_fd;
115 _retired.push_back (pe);
116
117 // Decrease the load metric of the thread.
118 adjust_load (-1);
119}
120
121void zmq::epoll_t::set_pollin (handle_t handle_)
122{
123 check_thread ();
124 poll_entry_t *pe = static_cast<poll_entry_t *> (handle_);
125 pe->ev.events |= EPOLLIN;
126 int rc = epoll_ctl (_epoll_fd, EPOLL_CTL_MOD, pe->fd, &pe->ev);
127 errno_assert (rc != -1);
128}
129
130void zmq::epoll_t::reset_pollin (handle_t handle_)
131{
132 check_thread ();
133 poll_entry_t *pe = static_cast<poll_entry_t *> (handle_);
134 pe->ev.events &= ~(static_cast<short> (EPOLLIN));
135 int rc = epoll_ctl (_epoll_fd, EPOLL_CTL_MOD, pe->fd, &pe->ev);
136 errno_assert (rc != -1);
137}
138
139void zmq::epoll_t::set_pollout (handle_t handle_)
140{
141 check_thread ();
142 poll_entry_t *pe = static_cast<poll_entry_t *> (handle_);
143 pe->ev.events |= EPOLLOUT;
144 int rc = epoll_ctl (_epoll_fd, EPOLL_CTL_MOD, pe->fd, &pe->ev);
145 errno_assert (rc != -1);
146}
147
148void zmq::epoll_t::reset_pollout (handle_t handle_)
149{
150 check_thread ();
151 poll_entry_t *pe = static_cast<poll_entry_t *> (handle_);
152 pe->ev.events &= ~(static_cast<short> (EPOLLOUT));
153 int rc = epoll_ctl (_epoll_fd, EPOLL_CTL_MOD, pe->fd, &pe->ev);
154 errno_assert (rc != -1);
155}
156
157void zmq::epoll_t::stop ()
158{
159 check_thread ();
160}
161
162int zmq::epoll_t::max_fds ()
163{
164 return -1;
165}
166
167void zmq::epoll_t::loop ()
168{
169 epoll_event ev_buf[max_io_events];
170
171 while (true) {
172 // Execute any due timers.
173 int timeout = static_cast<int> (execute_timers ());
174
175 if (get_load () == 0) {
176 if (timeout == 0)
177 break;
178
179 // TODO sleep for timeout
180 continue;
181 }
182
183 // Wait for events.
184 int n = epoll_wait (_epoll_fd, &ev_buf[0], max_io_events,
185 timeout ? timeout : -1);
186 if (n == -1) {
187 errno_assert (errno == EINTR);
188 continue;
189 }
190
191 for (int i = 0; i < n; i++) {
192 poll_entry_t *pe =
193 (static_cast<poll_entry_t *> (ev_buf[i].data.ptr));
194
195 if (pe->fd == retired_fd)
196 continue;
197 if (ev_buf[i].events & (EPOLLERR | EPOLLHUP))
198 pe->events->in_event ();
199 if (pe->fd == retired_fd)
200 continue;
201 if (ev_buf[i].events & EPOLLOUT)
202 pe->events->out_event ();
203 if (pe->fd == retired_fd)
204 continue;
205 if (ev_buf[i].events & EPOLLIN)
206 pe->events->in_event ();
207 }
208
209 // Destroy retired event sources.
210 for (retired_t::iterator it = _retired.begin (), end = _retired.end ();
211 it != end; ++it) {
212 LIBZMQ_DELETE (*it);
213 }
214 _retired.clear ();
215 }
216}
217
218#endif
219