src/socketengine_select.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
   6  *                       E-mail:
   7  *                <brain@chatspike.net>
   8  *                <Craig@chatspike.net>
   9  *
  10  * Written by Craig Edwards, Craig McLure, and others.
  11  * This program is free but copyrighted software; see
  12  *            the file COPYING for details.
  13  *
  14  * ---------------------------------------------------
  15  */
  16
  17 #include "inspircd.h"
  18 #include <sys/select.h>
  19 #include "socketengine_select.h"
  20
  21
  22 SelectEngine::SelectEngine(InspIRCd* Instance) : SocketEngine(Instance)
  23 {
  24         ServerInstance->Log(DEBUG,"SelectEngine::SelectEngine()");
  25         EngineHandle = 0;
  26         CurrentSetSize = 0;
  27         memset(writeable, 0, sizeof(writeable));
  28 }
  29
  30 SelectEngine::~SelectEngine()
  31 {
  32         ServerInstance->Log(DEBUG,"SelectEngine::~SelectEngine()");
  33 }
  34
  35 bool SelectEngine::AddFd(EventHandler* eh)
  36 {
  37         int fd = eh->GetFd();
  38         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  39         {
  40                 ServerInstance->Log(DEFAULT,"ERROR: FD of %d added above max of %d",fd,MAX_DESCRIPTORS);
  41                 return false;
  42         }
  43         if (GetRemainingFds() <= 1)
  44         {
  45                 ServerInstance->Log(DEFAULT,"ERROR: System out of file descriptors!");
  46                 return false;
  47         }
  48
  49         fds[fd] = fd;
  50
  51         if (ref[fd])
  52                 return false;
  53
  54         ref[fd] = eh;
  55         ServerInstance->Log(DEBUG,"Add socket %d",fd);
  56
  57         CurrentSetSize++;
  58         return true;
  59 }
  60
  61 void SelectEngine::WantWrite(EventHandler* eh)
  62 {
  63         writeable[eh->GetFd()] = true;
  64 }
  65
  66 bool SelectEngine::DelFd(EventHandler* eh)
  67 {
  68         int fd = eh->GetFd();
  69
  70         ServerInstance->Log(DEBUG,"SelectEngine::DelFd(%d)",fd);
  71
  72         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  73                 return false;
  74
  75         std::map<int,int>::iterator t = fds.find(fd);
  76         if (t != fds.end())
  77         {
  78                 fds.erase(t);
  79                 ServerInstance->Log(DEBUG,"Deleted fd %d",fd);
  80         }
  81
  82         CurrentSetSize--;
  83         ref[fd] = NULL;
  84         return true;
  85 }
  86
  87 int SelectEngine::GetMaxFds()
  88 {
  89         return FD_SETSIZE;
  90 }
  91
  92 int SelectEngine::GetRemainingFds()
  93 {
  94         return FD_SETSIZE - CurrentSetSize;
  95 }
  96
  97 int SelectEngine::DispatchEvents()
  98 {
  99         int result = 0;
 100         timeval tval;
 101         int sresult = 0;
 102         EventHandler* ev[MAX_DESCRIPTORS];
 103
 104         FD_ZERO(&wfdset);
 105         FD_ZERO(&rfdset);
 106         FD_ZERO(&errfdset);
 107
 108         for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 109         {
 110                 if (ref[a->second]->Readable())
 111                         FD_SET (a->second, &rfdset);
 112                 else
 113                         FD_SET (a->second, &wfdset);
 114                 if (writeable[a->second])
 115                         FD_SET (a->second, &wfdset);
 116
 117                 FD_SET (a->second, &errfdset);
 118         }
 119         tval.tv_sec = 0;
 120         tval.tv_usec = 50L;
 121         sresult = select(FD_SETSIZE, &rfdset, &wfdset, &errfdset, &tval);
 122         if (sresult > 0)
 123         {
 124                 for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 125                 {
 126                         if ((FD_ISSET (a->second, &rfdset)) || (FD_ISSET (a->second, &wfdset)) || FD_ISSET (a->second, &errfdset))
 127                         {
 128                                 ev[result++] = ref[a->second];
 129                         }
 130                 }
 131         }
 132
 133         /** An event handler may remove its own descriptor from the list, therefore it is not
 134          * safe to directly iterate over the list and dispatch events there with STL iterators.
 135          * Thats a shame because it makes this code slower and more resource intensive, but maybe
 136          * the user should stop using select(), as select() smells anyway.
 137          */
 138         for (int i = 0; i < result; i++)
 139         {
 140                 if (ev[i])
 141                 {
 142                         if (FD_ISSET (a->second, &errfdset))
 143                         {
 144                                 if (ev[i])
 145                                         ev[i]->HandleEvent(EVENT_ERROR, 0);
 146                                 continue;
 147                         }
 148                         ServerInstance->Log(DEBUG,"Handle %s event on fd %d",writeable[ev[i]->GetFd()] || !ev[i]->Readable() ? "write" : "read", ev[i]->GetFd());
 149                         if (writeable[ev[i]->GetFd()])
 150                         {
 151                                 if (ev[i])
 152                                         ev[i]->HandleEvent(EVENT_WRITE);
 153                                 writeable[ev[i]->GetFd()] = false;
 154
 155                         }
 156                         else
 157                         {
 158                                 if (ev[i])
 159                                         ev[i]->HandleEvent(ev[i]->Readable() ? EVENT_READ : EVENT_WRITE);
 160                         }
 161                 }
 162         }
 163
 164         return result;
 165 }
 166
 167 std::string SelectEngine::GetName()
 168 {
 169         return "select";
 170 }