src/socketengine_select.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2007 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 "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         fds[fd] = fd;
  40
  41         if (ref[fd])
  42                 return false;
  43
  44         ref[fd] = eh;
  45
  46         CurrentSetSize++;
  47
  48         ServerInstance->Log(DEBUG,"New file descriptor: %d", fd);
  49         return true;
  50 }
  51
  52 void SelectEngine::WantWrite(EventHandler* eh)
  53 {
  54         writeable[eh->GetFd()] = true;
  55 }
  56
  57 bool SelectEngine::DelFd(EventHandler* eh, bool force)
  58 {
  59         int fd = eh->GetFd();
  60
  61         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  62                 return false;
  63
  64         std::map<int,int>::iterator t = fds.find(fd);
  65         if (t != fds.end())
  66                 fds.erase(t);
  67
  68         CurrentSetSize--;
  69         ref[fd] = NULL;
  70
  71         ServerInstance->Log(DEBUG,"Remove file descriptor: %d", fd);
  72         return true;
  73 }
  74
  75 int SelectEngine::GetMaxFds()
  76 {
  77         return FD_SETSIZE;
  78 }
  79
  80 int SelectEngine::GetRemainingFds()
  81 {
  82         return FD_SETSIZE - CurrentSetSize;
  83 }
  84
  85 int SelectEngine::DispatchEvents()
  86 {
  87         int result = 0;
  88         timeval tval;
  89         int sresult = 0;
  90         EventHandler* ev[MAX_DESCRIPTORS];
  91         socklen_t codesize;
  92         int errcode;
  93
  94         FD_ZERO(&wfdset);
  95         FD_ZERO(&rfdset);
  96         FD_ZERO(&errfdset);
  97
  98         for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
  99         {
 100                 if (ref[a->second]->Readable())
 101                         FD_SET (a->second, &rfdset);
 102                 else
 103                         FD_SET (a->second, &wfdset);
 104                 if (writeable[a->second])
 105                         FD_SET (a->second, &wfdset);
 106
 107                 FD_SET (a->second, &errfdset);
 108         }
 109         tval.tv_sec = 1;
 110         tval.tv_usec = 0;
 111         sresult = select(FD_SETSIZE, &rfdset, &wfdset, &errfdset, &tval);
 112         if (sresult > 0)
 113         {
 114                 for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 115                 {
 116                         if ((FD_ISSET (a->second, &rfdset)) || (FD_ISSET (a->second, &wfdset)) || FD_ISSET (a->second, &errfdset))
 117                         {
 118                                 ev[result++] = ref[a->second];
 119                         }
 120                 }
 121         }
 122
 123         /** An event handler may remove its own descriptor from the list, therefore it is not
 124          * safe to directly iterate over the list and dispatch events there with STL iterators.
 125          * Thats a shame because it makes this code slower and more resource intensive, but maybe
 126          * the user should stop using select(), as select() smells anyway.
 127          */
 128         for (int i = 0; i < result; i++)
 129         {
 130                 if (ev[i])
 131                 {
 132                         if (FD_ISSET (ev[i]->GetFd(), &errfdset))
 133                         {
 134                                 if (ev[i])
 135                                 {
 136                                         if (getsockopt(ev[i]->GetFd(), SOL_SOCKET, SO_ERROR, &errcode, &codesize) < 0)
 137                                                 errcode = errno;
 138
 139                                         ev[i]->HandleEvent(EVENT_ERROR, errcode);
 140                                 }
 141                                 continue;
 142                         }
 143                         if (ev[i])
 144                         {
 145                                 if (writeable[ev[i]->GetFd()])
 146                                 {
 147                                         if (ev[i])
 148                                                 ev[i]->HandleEvent(EVENT_WRITE);
 149                                         writeable[ev[i]->GetFd()] = false;
 150
 151                                 }
 152                                 else
 153                                 {
 154                                         if (ev[i])
 155                                                 ev[i]->HandleEvent(ev[i]->Readable() ? EVENT_READ : EVENT_WRITE);
 156                                 }
 157                         }
 158                 }
 159         }
 160
 161         return result;
 162 }
 163
 164 std::string SelectEngine::GetName()
 165 {
 166         return "select";
 167 }