src/socketengines/socketengine_select.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2008 InspIRCd Development Team
   6  * See: http://www.inspircd.org/wiki/index.php/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include <sys/select.h>
  16 #include "socketengines/socketengine_select.h"
  17
  18
  19 SelectEngine::SelectEngine(InspIRCd* Instance) : SocketEngine(Instance)
  20 {
  21         EngineHandle = 0;
  22         CurrentSetSize = 0;
  23         memset(writeable, 0, sizeof(writeable));
  24 }
  25
  26 SelectEngine::~SelectEngine()
  27 {
  28 }
  29
  30 bool SelectEngine::AddFd(EventHandler* eh)
  31 {
  32         int fd = eh->GetFd();
  33         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  34                 return false;
  35
  36         if (GetRemainingFds() <= 1)
  37                 return false;
  38
  39         if (ref[fd])
  40                 return false;
  41
  42         fds[fd] = fd;
  43         ref[fd] = eh;
  44         CurrentSetSize++;
  45
  46         ServerInstance->Log(DEBUG,"New file descriptor: %d", fd);
  47         return true;
  48 }
  49
  50 void SelectEngine::WantWrite(EventHandler* eh)
  51 {
  52         writeable[eh->GetFd()] = true;
  53 }
  54
  55 bool SelectEngine::DelFd(EventHandler* eh, bool force)
  56 {
  57         int fd = eh->GetFd();
  58
  59         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  60                 return false;
  61
  62         std::map<int,int>::iterator t = fds.find(fd);
  63         if (t != fds.end())
  64                 fds.erase(t);
  65
  66         CurrentSetSize--;
  67         ref[fd] = NULL;
  68         fds[fd] = 0;
  69
  70         ServerInstance->Log(DEBUG,"Remove file descriptor: %d", fd);
  71         return true;
  72 }
  73
  74 int SelectEngine::GetMaxFds()
  75 {
  76         return FD_SETSIZE;
  77 }
  78
  79 int SelectEngine::GetRemainingFds()
  80 {
  81         return FD_SETSIZE - CurrentSetSize;
  82 }
  83
  84 int SelectEngine::DispatchEvents()
  85 {
  86         int result = 0;
  87         timeval tval;
  88         int sresult = 0;
  89         EventHandler* ev[MAX_DESCRIPTORS];
  90         socklen_t codesize;
  91         int errcode;
  92
  93         FD_ZERO(&wfdset);
  94         FD_ZERO(&rfdset);
  95         FD_ZERO(&errfdset);
  96
  97         for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
  98         {
  99                 if (ref[a->second]->Readable())
 100                         FD_SET (a->second, &rfdset);
 101                 else
 102                         FD_SET (a->second, &wfdset);
 103                 if (writeable[a->second])
 104                         FD_SET (a->second, &wfdset);
 105
 106                 FD_SET (a->second, &errfdset);
 107         }
 108         tval.tv_sec = 1;
 109         tval.tv_usec = 0;
 110         sresult = select(FD_SETSIZE, &rfdset, &wfdset, &errfdset, &tval);
 111         if (sresult > 0)
 112         {
 113                 for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 114                 {
 115                         if ((FD_ISSET (a->second, &rfdset)) || (FD_ISSET (a->second, &wfdset)) || FD_ISSET (a->second, &errfdset))
 116                         {
 117                                 ev[result++] = ref[a->second];
 118                         }
 119                 }
 120         }
 121
 122         /** An event handler may remove its own descriptor from the list, therefore it is not
 123          * safe to directly iterate over the list and dispatch events there with STL iterators.
 124          * Thats a shame because it makes this code slower and more resource intensive, but maybe
 125          * the user should stop using select(), as select() smells anyway.
 126          */
 127         for (int i = 0; i < result; i++)
 128         {
 129                 if (ev[i])
 130                 {
 131                         if (FD_ISSET (ev[i]->GetFd(), &errfdset))
 132                         {
 133                                 if (ev[i])
 134                                 {
 135                                         if (getsockopt(ev[i]->GetFd(), SOL_SOCKET, SO_ERROR, &errcode, &codesize) < 0)
 136                                                 errcode = errno;
 137
 138                                         ev[i]->HandleEvent(EVENT_ERROR, errcode);
 139                                 }
 140                                 continue;
 141                         }
 142                         if (ev[i])
 143                         {
 144                                 if (writeable[ev[i]->GetFd()])
 145                                 {
 146                                         writeable[ev[i]->GetFd()] = false;
 147                                         if (ev[i])
 148                                                 ev[i]->HandleEvent(EVENT_WRITE);
 149                                 }
 150                                 else
 151                                 {
 152                                         if (ev[i])
 153                                                 ev[i]->HandleEvent(ev[i]->Readable() ? EVENT_READ : EVENT_WRITE);
 154                                 }
 155                         }
 156                 }
 157         }
 158
 159         return result;
 160 }
 161
 162 std::string SelectEngine::GetName()
 163 {
 164         return "select";
 165 }