src/socketengines/socketengine_select.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2014 Adam <Adam@anope.org>
   5  *   Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
   6  *   Copyright (C) 2007-2008 Craig Edwards <craigedwards@brainbox.cc>
   7  *
   8  * This file is part of InspIRCd.  InspIRCd is free software: you can
   9  * redistribute it and/or modify it under the terms of the GNU General Public
  10  * License as published by the Free Software Foundation, version 2.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  14  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  15  * details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21
  22 #include "inspircd.h"
  23 #include "socketengine.h"
  24
  25 #ifndef _WIN32
  26 #include <sys/select.h>
  27 #endif // _WIN32
  28
  29 /** A specialisation of the SocketEngine class, designed to use traditional select().
  30  */
  31 class SelectEngine : public SocketEngine
  32 {
  33         fd_set ReadSet, WriteSet, ErrSet;
  34         int MaxFD;
  35
  36 public:
  37         /** Create a new SelectEngine
  38          */
  39         SelectEngine();
  40         virtual bool AddFd(EventHandler* eh, int event_mask);
  41         virtual void DelFd(EventHandler* eh);
  42         void OnSetEvent(EventHandler* eh, int, int);
  43         virtual int DispatchEvents();
  44         virtual std::string GetName();
  45 };
  46
  47 SelectEngine::SelectEngine()
  48 {
  49         MAX_DESCRIPTORS = FD_SETSIZE;
  50         CurrentSetSize = 0;
  51
  52         FD_ZERO(&ReadSet);
  53         FD_ZERO(&WriteSet);
  54         FD_ZERO(&ErrSet);
  55         MaxFD = 0;
  56 }
  57
  58 bool SelectEngine::AddFd(EventHandler* eh, int event_mask)
  59 {
  60         int fd = eh->GetFd();
  61         if ((fd < 0) || (fd > GetMaxFds() - 1))
  62                 return false;
  63
  64         if (!SocketEngine::AddFd(eh))
  65                 return false;
  66
  67         SocketEngine::SetEventMask(eh, event_mask);
  68         OnSetEvent(eh, 0, event_mask);
  69         FD_SET(fd, &ErrSet);
  70         if (fd > MaxFD)
  71                 MaxFD = fd;
  72
  73         CurrentSetSize++;
  74
  75         ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "New file descriptor: %d", fd);
  76         return true;
  77 }
  78
  79 void SelectEngine::DelFd(EventHandler* eh)
  80 {
  81         int fd = eh->GetFd();
  82
  83         if ((fd < 0) || (fd > GetMaxFds() - 1))
  84                 return;
  85
  86         CurrentSetSize--;
  87         SocketEngine::DelFd(eh);
  88
  89         FD_CLR(fd, &ReadSet);
  90         FD_CLR(fd, &WriteSet);
  91         FD_CLR(fd, &ErrSet);
  92         if (fd == MaxFD)
  93                 --MaxFD;
  94
  95         ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "Remove file descriptor: %d", fd);
  96 }
  97
  98 void SelectEngine::OnSetEvent(EventHandler* eh, int old_mask, int new_mask)
  99 {
 100         int fd = eh->GetFd();
 101         int diff = old_mask ^ new_mask;
 102
 103         if (diff & (FD_WANT_POLL_READ | FD_WANT_FAST_READ))
 104         {
 105                 if (new_mask & (FD_WANT_POLL_READ | FD_WANT_FAST_READ))
 106                         FD_SET(fd, &ReadSet);
 107                 else
 108                         FD_CLR(fd, &ReadSet);
 109         }
 110         if (diff & (FD_WANT_POLL_WRITE | FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE))
 111         {
 112                 if (new_mask & (FD_WANT_POLL_WRITE | FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE))
 113                         FD_SET(fd, &WriteSet);
 114                 else
 115                         FD_CLR(fd, &WriteSet);
 116         }
 117 }
 118
 119 int SelectEngine::DispatchEvents()
 120 {
 121         static timeval tval = { 1, 0 };
 122
 123         fd_set rfdset = ReadSet, wfdset = WriteSet, errfdset = ErrSet;
 124
 125         int sresult = select(MaxFD + 1, &rfdset, &wfdset, &errfdset, &tval);
 126         ServerInstance->UpdateTime();
 127
 128         for (int i = 0, j = sresult; i <= MaxFD && j > 0; i++)
 129         {
 130                 int has_read = FD_ISSET(i, &rfdset), has_write = FD_ISSET(i, &wfdset), has_error = FD_ISSET(i, &errfdset);
 131
 132                 if (!(has_read || has_write || has_error))
 133                         continue;
 134
 135                 --j;
 136
 137                 EventHandler* ev = GetRef(i);
 138                 if (!ev)
 139                         continue;
 140
 141                 if (has_error)
 142                 {
 143                         ErrorEvents++;
 144
 145                         socklen_t codesize = sizeof(int);
 146                         int errcode = 0;
 147                         if (getsockopt(i, SOL_SOCKET, SO_ERROR, (char*)&errcode, &codesize) < 0)
 148                                 errcode = errno;
 149
 150                         ev->HandleEvent(EVENT_ERROR, errcode);
 151                         continue;
 152                 }
 153
 154                 if (has_read)
 155                 {
 156                         ReadEvents++;
 157                         SetEventMask(ev, ev->GetEventMask() & ~FD_READ_WILL_BLOCK);
 158                         ev->HandleEvent(EVENT_READ);
 159                         if (ev != GetRef(i))
 160                                 continue;
 161                 }
 162
 163                 if (has_write)
 164                 {
 165                         WriteEvents++;
 166                         int newmask = (ev->GetEventMask() & ~(FD_WRITE_WILL_BLOCK | FD_WANT_SINGLE_WRITE));
 167                         this->OnSetEvent(ev, ev->GetEventMask(), newmask);
 168                         SetEventMask(ev, newmask);
 169                         ev->HandleEvent(EVENT_WRITE);
 170                 }
 171         }
 172
 173         return sresult;
 174 }
 175
 176 std::string SelectEngine::GetName()
 177 {
 178         return "select";
 179 }
 180
 181 SocketEngine* CreateSocketEngine()
 182 {
 183         return new SelectEngine;
 184 }