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 #ifndef WINDOWS
  16 #include <sys/select.h>
  17 #endif // WINDOWS
  18 #include "socketengines/socketengine_select.h"
  19
  20
  21 SelectEngine::SelectEngine(InspIRCd* Instance) : SocketEngine(Instance)
  22 {
  23         EngineHandle = 0;
  24         CurrentSetSize = 0;
  25         memset(writeable, 0, sizeof(writeable));
  26 }
  27
  28 SelectEngine::~SelectEngine()
  29 {
  30 }
  31
  32 bool SelectEngine::AddFd(EventHandler* eh)
  33 {
  34         int fd = eh->GetFd();
  35         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  36                 return false;
  37
  38         if (GetRemainingFds() <= 1)
  39                 return false;
  40
  41         if (ref[fd])
  42                 return false;
  43
  44         fds[fd] = fd;
  45         ref[fd] = eh;
  46         CurrentSetSize++;
  47
  48         ServerInstance->Logs->Log("SOCKET",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         fds[fd] = 0;
  71
  72         ServerInstance->Logs->Log("SOCKET",DEBUG,"Remove file descriptor: %d", fd);
  73         return true;
  74 }
  75
  76 int SelectEngine::GetMaxFds()
  77 {
  78         return FD_SETSIZE;
  79 }
  80
  81 int SelectEngine::GetRemainingFds()
  82 {
  83         return FD_SETSIZE - CurrentSetSize;
  84 }
  85
  86 int SelectEngine::DispatchEvents()
  87 {
  88         int result = 0;
  89         timeval tval;
  90         int sresult = 0;
  91         EventHandler* ev[MAX_DESCRIPTORS];
  92         socklen_t codesize;
  93         int errcode;
  94
  95         FD_ZERO(&wfdset);
  96         FD_ZERO(&rfdset);
  97         FD_ZERO(&errfdset);
  98
  99         for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 100         {
 101                 if (ref[a->second]->Readable())
 102                         FD_SET (a->second, &rfdset);
 103                 else
 104                         FD_SET (a->second, &wfdset);
 105                 if (writeable[a->second])
 106                         FD_SET (a->second, &wfdset);
 107
 108                 FD_SET (a->second, &errfdset);
 109         }
 110         tval.tv_sec = 1;
 111         tval.tv_usec = 0;
 112         sresult = select(FD_SETSIZE, &rfdset, &wfdset, &errfdset, &tval);
 113         if (sresult > 0)
 114         {
 115                 for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 116                 {
 117                         if ((FD_ISSET (a->second, &rfdset)) || (FD_ISSET (a->second, &wfdset)) || FD_ISSET (a->second, &errfdset))
 118                         {
 119                                 ev[result++] = ref[a->second];
 120                         }
 121                 }
 122         }
 123
 124         /** An event handler may remove its own descriptor from the list, therefore it is not
 125          * safe to directly iterate over the list and dispatch events there with STL iterators.
 126          * Thats a shame because it makes this code slower and more resource intensive, but maybe
 127          * the user should stop using select(), as select() smells anyway.
 128          */
 129         for (int i = 0; i < result; i++)
 130         {
 131                 if (ev[i])
 132                 {
 133                         if (FD_ISSET (ev[i]->GetFd(), &errfdset))
 134                         {
 135                                 ErrorEvents++;
 136
 137                                 if (getsockopt(ev[i]->GetFd(), SOL_SOCKET, SO_ERROR, (char*)&errcode, &codesize) < 0)
 138                                         errcode = errno;
 139
 140                                 ev[i]->HandleEvent(EVENT_ERROR, errcode);
 141
 142                                 continue;
 143                         }
 144                         else
 145                         {
 146                                 if (writeable[ev[i]->GetFd()])
 147                                 {
 148                                         WriteEvents++;
 149                                         writeable[ev[i]->GetFd()] = false;
 150                                         ev[i]->HandleEvent(EVENT_WRITE);
 151                                 }
 152                                 else
 153                                 {
 154                                         if (ev[i]->Readable())
 155                                         {
 156                                                 ReadEvents++;
 157                                                 ev[i]->HandleEvent(EVENT_READ);
 158                                         }
 159                                         else
 160                                         {
 161                                                 WriteEvents++;
 162                                                 ev[i]->HandleEvent(EVENT_WRITE);
 163                                         }
 164                                 }
 165                         }
 166                 }
 167         }
 168
 169         return result;
 170 }
 171
 172 std::string SelectEngine::GetName()
 173 {
 174         return "select";
 175 }