~singpolyma/biboumi

ref: 7b3e0e0cf3eddd3537455a3605b04a48ee663f47 biboumi/src/network/poller.cpp -rw-r--r-- 6.9 KiB
7b3e0e0c — louiz’ Make botan’s policy configurable from a file 5 years ago
                                                                                
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
#include <network/poller.hpp>
#include <logger/logger.hpp>
#include <utils/timed_events.hpp>

#include <cassert>
#include <cerrno>
#include <stdio.h>
#include <signal.h>
#include <unistd.h>

#include <cstring>
#include <iostream>
#include <stdexcept>

Poller::Poller()
{
#if POLLER == POLL
  this->nfds = 0;
#elif POLLER == EPOLL
  this->epfd = ::epoll_create1(0);
  if (this->epfd == -1)
    {
      log_error("epoll failed: ", strerror(errno));
      throw std::runtime_error("Could not create epoll instance");
    }
#endif
}

Poller::~Poller()
{
#if POLLER == EPOLL
  if (this->epfd > 0)
    ::close(this->epfd);
#endif
}

void Poller::add_socket_handler(SocketHandler* socket_handler)
{
  // Don't do anything if the socket is already managed
  const auto it = this->socket_handlers.find(socket_handler->get_socket());
  if (it != this->socket_handlers.end())
    return ;

  this->socket_handlers.emplace(socket_handler->get_socket(), socket_handler);

  // We always watch all sockets for receive events
#if POLLER == POLL
  this->fds[this->nfds].fd = socket_handler->get_socket();
  this->fds[this->nfds].events = POLLIN;
  this->nfds++;
#endif
#if POLLER == EPOLL
  struct epoll_event event = {EPOLLIN, {socket_handler}};
  const int res = ::epoll_ctl(this->epfd, EPOLL_CTL_ADD, socket_handler->get_socket(), &event);
  if (res == -1)
    {
      log_error("epoll_ctl failed: ", strerror(errno));
      throw std::runtime_error("Could not add socket to epoll");
    }
#endif
}

void Poller::remove_socket_handler(const socket_t socket)
{
  const auto it = this->socket_handlers.find(socket);
  if (it == this->socket_handlers.end())
    throw std::runtime_error("Trying to remove a SocketHandler that is not managed");
  this->socket_handlers.erase(it);

#if POLLER == POLL
  for (size_t i = 0; i < this->nfds; i++)
    {
      if (this->fds[i].fd == socket)
        {
          // Move all subsequent pollfd by one on the left, erasing the
          // value of the one we remove
          for (size_t j = i; j < this->nfds - 1; ++j)
            {
              this->fds[j].fd = this->fds[j+1].fd;
              this->fds[j].events= this->fds[j+1].events;
            }
          this->nfds--;
        }
    }
#elif POLLER == EPOLL
  const int res = ::epoll_ctl(this->epfd, EPOLL_CTL_DEL, socket, nullptr);
  if (res == -1)
    {
      log_error("epoll_ctl failed: ", strerror(errno));
      throw std::runtime_error("Could not remove socket from epoll");
    }
#endif
}

void Poller::watch_send_events(SocketHandler* socket_handler)
{
#if POLLER == POLL
  for (size_t i = 0; i < this->nfds; ++i)
    {
      if (this->fds[i].fd == socket_handler->get_socket())
        {
          this->fds[i].events = POLLIN|POLLOUT;
          return;
        }
    }
  throw std::runtime_error("Cannot watch a non-registered socket for send events");
#elif POLLER == EPOLL
  struct epoll_event event = {EPOLLIN|EPOLLOUT, {socket_handler}};
  const int res = ::epoll_ctl(this->epfd, EPOLL_CTL_MOD, socket_handler->get_socket(), &event);
  if (res == -1)
    {
      log_error("epoll_ctl failed: ", strerror(errno));
      throw std::runtime_error("Could not modify socket flags in epoll");
    }
#endif
}

void Poller::stop_watching_send_events(SocketHandler* socket_handler)
{
#if POLLER == POLL
  for (size_t i = 0; i <= this->nfds; ++i)
    {
      if (this->fds[i].fd == socket_handler->get_socket())
        {
          this->fds[i].events = POLLIN;
          return;
        }
    }
  throw std::runtime_error("Cannot watch a non-registered socket for send events");
#elif POLLER == EPOLL
  struct epoll_event event = {EPOLLIN, {socket_handler}};
  const int res = ::epoll_ctl(this->epfd, EPOLL_CTL_MOD, socket_handler->get_socket(), &event);
  if (res == -1)
    {
      log_error("epoll_ctl failed: ", strerror(errno));
      throw std::runtime_error("Could not modify socket flags in epoll");
    }
#endif
}

int Poller::poll(const std::chrono::milliseconds& timeout)
{
  if (this->socket_handlers.empty() && timeout == utils::no_timeout)
    return -1;
#if POLLER == POLL
  // Convert our nice timeout into this ugly struct
  struct timespec timeout_ts;
  struct timespec* timeout_tsp;
  if (timeout > 0s)
    {
      auto seconds = std::chrono::duration_cast<std::chrono::seconds>(timeout);
      timeout_ts.tv_sec = seconds.count();
      timeout_ts.tv_nsec = std::chrono::duration_cast<std::chrono::nanoseconds>(timeout - seconds).count();
      timeout_tsp = &timeout_ts;
    }
  else
    timeout_tsp = nullptr;

  // Unblock all signals, only during the ppoll call
  sigset_t empty_signal_set;
  sigemptyset(&empty_signal_set);
  int nb_events = ::ppoll(this->fds, this->nfds, timeout_tsp,
                          &empty_signal_set);
  if (nb_events < 0)
    {
      if (errno == EINTR)
        return true;
      log_error("poll failed: ", strerror(errno));
      throw std::runtime_error("Poll failed");
    }
  // We cannot possibly have more ready events than the number of fds we are
  // watching
  assert(static_cast<unsigned int>(nb_events) <= this->nfds);
  for (size_t i = 0; i < this->nfds && nb_events != 0; ++i)
    {
      auto socket_handler = this->socket_handlers.at(this->fds[i].fd);
      if (this->fds[i].revents == 0)
        continue;
      else if (this->fds[i].revents & POLLIN && socket_handler->is_connected())
        {
          socket_handler->on_recv();
          nb_events--;
        }
      else if (this->fds[i].revents & POLLOUT && socket_handler->is_connected())
        {
            socket_handler->on_send();
            nb_events--;
        }
      else if (this->fds[i].revents & POLLOUT ||
               this->fds[i].revents & POLLIN)
        {
          socket_handler->connect();
          nb_events--;
        }
    }
  return 1;
#elif POLLER == EPOLL
  static const size_t max_events = 12;
  struct epoll_event revents[max_events];
  // Unblock all signals, only during the epoll_pwait call
  sigset_t empty_signal_set{};
  sigemptyset(&empty_signal_set);
  const int nb_events = ::epoll_pwait(this->epfd, revents, max_events, timeout.count(),
                                      &empty_signal_set);
  if (nb_events == -1)
    {
      if (errno == EINTR)
        return 0;
      log_error("epoll wait: ", strerror(errno));
      throw std::runtime_error("Epoll_wait failed");
    }
  for (int i = 0; i < nb_events; ++i)
    {
      auto socket_handler = static_cast<SocketHandler*>(revents[i].data.ptr);
      if (revents[i].events & EPOLLIN && socket_handler->is_connected())
        socket_handler->on_recv();
      else if (revents[i].events & EPOLLOUT && socket_handler->is_connected())
        socket_handler->on_send();
      else if (revents[i].events & EPOLLOUT)
        socket_handler->connect();
    }
  return nb_events;
#endif
}

size_t Poller::size() const
{
  return this->socket_handlers.size();
}

bool Poller::is_managing_socket(const socket_t socket) const
{
  return (this->socket_handlers.find(socket) != this->socket_handlers.end());
}