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 };
  45
  46 SelectEngine::SelectEngine()
  47 {
  48         MAX_DESCRIPTORS = FD_SETSIZE;
  49         CurrentSetSize = 0;
  50
  51         FD_ZERO(&ReadSet);
  52         FD_ZERO(&WriteSet);
  53         FD_ZERO(&ErrSet);
  54         MaxFD = 0;
  55 }
  56
  57 bool SelectEngine::AddFd(EventHandler* eh, int event_mask)
  58 {
  59         int fd = eh->GetFd();
  60         if ((fd < 0) || (fd > GetMaxFds() - 1))
  61                 return false;
  62
  63         if (!SocketEngine::AddFd(eh))
  64                 return false;
  65
  66         SocketEngine::SetEventMask(eh, event_mask);
  67         OnSetEvent(eh, 0, event_mask);
  68         FD_SET(fd, &ErrSet);
  69         if (fd > MaxFD)
  70                 MaxFD = fd;
  71
  72         CurrentSetSize++;
  73
  74         ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "New file descriptor: %d", fd);
  75         return true;
  76 }
  77
  78 void SelectEngine::DelFd(EventHandler* eh)
  79 {
  80         int fd = eh->GetFd();
  81
  82         if ((fd < 0) || (fd > GetMaxFds() - 1))
  83                 return;
  84
  85         CurrentSetSize--;
  86         SocketEngine::DelFd(eh);
  87
  88         FD_CLR(fd, &ReadSet);
  89         FD_CLR(fd, &WriteSet);
  90         FD_CLR(fd, &ErrSet);
  91         if (fd == MaxFD)
  92                 --MaxFD;
  93
  94         ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "Remove file descriptor: %d", fd);
  95 }
  96
  97 void SelectEngine::OnSetEvent(EventHandler* eh, int old_mask, int new_mask)
  98 {
  99         int fd = eh->GetFd();
 100         int diff = old_mask ^ new_mask;
 101
 102         if (diff & (FD_WANT_POLL_READ | FD_WANT_FAST_READ))
 103         {
 104                 if (new_mask & (FD_WANT_POLL_READ | FD_WANT_FAST_READ))
 105                         FD_SET(fd, &ReadSet);
 106                 else
 107                         FD_CLR(fd, &ReadSet);
 108         }
 109         if (diff & (FD_WANT_POLL_WRITE | FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE))
 110         {
 111                 if (new_mask & (FD_WANT_POLL_WRITE | FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE))
 112                         FD_SET(fd, &WriteSet);
 113                 else
 114                         FD_CLR(fd, &WriteSet);
 115         }
 116 }
 117
 118 int SelectEngine::DispatchEvents()
 119 {
 120         static timeval tval = { 1, 0 };
 121
 122         fd_set rfdset = ReadSet, wfdset = WriteSet, errfdset = ErrSet;
 123
 124         int sresult = select(MaxFD + 1, &rfdset, &wfdset, &errfdset, &tval);
 125         ServerInstance->UpdateTime();
 126
 127         for (int i = 0, j = sresult; i <= MaxFD && j > 0; i++)
 128         {
 129                 int has_read = FD_ISSET(i, &rfdset), has_write = FD_ISSET(i, &wfdset), has_error = FD_ISSET(i, &errfdset);
 130
 131                 if (!(has_read || has_write || has_error))
 132                         continue;
 133
 134                 --j;
 135
 136                 EventHandler* ev = GetRef(i);
 137                 if (!ev)
 138                         continue;
 139
 140                 if (has_error)
 141                 {
 142                         ErrorEvents++;
 143
 144                         socklen_t codesize = sizeof(int);
 145                         int errcode = 0;
 146                         if (getsockopt(i, SOL_SOCKET, SO_ERROR, (char*)&errcode, &codesize) < 0)
 147                                 errcode = errno;
 148
 149                         ev->HandleEvent(EVENT_ERROR, errcode);
 150                         continue;
 151                 }
 152
 153                 if (has_read)
 154                 {
 155                         ReadEvents++;
 156                         SetEventMask(ev, ev->GetEventMask() & ~FD_READ_WILL_BLOCK);
 157                         ev->HandleEvent(EVENT_READ);
 158                         if (ev != GetRef(i))
 159                                 continue;
 160                 }
 161
 162                 if (has_write)
 163                 {
 164                         WriteEvents++;
 165                         int newmask = (ev->GetEventMask() & ~(FD_WRITE_WILL_BLOCK | FD_WANT_SINGLE_WRITE));
 166                         this->OnSetEvent(ev, ev->GetEventMask(), newmask);
 167                         SetEventMask(ev, newmask);
 168                         ev->HandleEvent(EVENT_WRITE);
 169                 }
 170         }
 171
 172         return sresult;
 173 }
 174
 175 SocketEngine* CreateSocketEngine()
 176 {
 177         return new SelectEngine;
 178 }