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 }
  28
  29 SelectEngine::~SelectEngine()
  30 {
  31         ServerInstance->Log(DEBUG,"SelectEngine::~SelectEngine()");
  32 }
  33
  34 bool SelectEngine::AddFd(EventHandler* eh)
  35 {
  36         int fd = eh->GetFd();
  37         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  38         {
  39                 ServerInstance->Log(DEFAULT,"ERROR: FD of %d added above max of %d",fd,MAX_DESCRIPTORS);
  40                 return false;
  41         }
  42         if (GetRemainingFds() <= 1)
  43         {
  44                 ServerInstance->Log(DEFAULT,"ERROR: System out of file descriptors!");
  45                 return false;
  46         }
  47
  48         fds[fd] = fd;
  49
  50         if (ref[fd])
  51                 return false;
  52
  53         ref[fd] = eh;
  54         ServerInstance->Log(DEBUG,"Add socket %d",fd);
  55
  56         CurrentSetSize++;
  57         return true;
  58 }
  59
  60 bool SelectEngine::DelFd(EventHandler* eh)
  61 {
  62         int fd = eh->GetFd();
  63
  64         ServerInstance->Log(DEBUG,"SelectEngine::DelFd(%d)",fd);
  65
  66         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  67                 return false;
  68
  69         std::map<int,int>::iterator t = fds.find(fd);
  70         if (t != fds.end())
  71         {
  72                 fds.erase(t);
  73                 ServerInstance->Log(DEBUG,"Deleted fd %d",fd);
  74         }
  75
  76         CurrentSetSize--;
  77         ref[fd] = NULL;
  78         return true;
  79 }
  80
  81 int SelectEngine::GetMaxFds()
  82 {
  83         return FD_SETSIZE;
  84 }
  85
  86 int SelectEngine::GetRemainingFds()
  87 {
  88         return FD_SETSIZE - CurrentSetSize;
  89 }
  90
  91 int SelectEngine::DispatchEvents()
  92 {
  93         int result = 0;
  94         timeval tval;
  95         int sresult = 0;
  96         EventHandler* ev[MAX_DESCRIPTORS];
  97
  98         FD_ZERO(&wfdset);
  99         FD_ZERO(&rfdset);
 100
 101         for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 102         {
 103                 if (ref[a->second]->Readable())
 104                 {
 105                         FD_SET (a->second, &rfdset);
 106                 }
 107                 else
 108                 {
 109                         FD_SET (a->second, &wfdset);
 110                 }
 111
 112         }
 113         tval.tv_sec = 0;
 114         tval.tv_usec = 50L;
 115         sresult = select(FD_SETSIZE, &rfdset, &wfdset, NULL, &tval);
 116         if (sresult > 0)
 117         {
 118                 for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 119                 {
 120                         if ((FD_ISSET (a->second, &rfdset)) || (FD_ISSET (a->second, &wfdset)))
 121                         {
 122                                 ev[result++] = ref[a->second];
 123                         }
 124                 }
 125         }
 126
 127         /** An event handler may remove its own descriptor from the list, therefore it is not
 128          * safe to directly iterate over the list and dispatch events there with STL iterators.
 129          * Thats a shame because it makes this code slower and more resource intensive, but maybe
 130          * the user should stop using select(), as select() smells anyway.
 131          */
 132         for (int i = 0; i < result; i++)
 133         {
 134                 ServerInstance->Log(DEBUG,"Handle %s event on fd %d",ev[i]->Readable() ? "read" : "write", ev[i]->GetFd());
 135                 ev[i]->HandleEvent(ev[i]->Readable() ? EVENT_READ : EVENT_WRITE);
 136         }
 137
 138         return result;
 139 }
 140
 141 std::string SelectEngine::GetName()
 142 {
 143         return "select";
 144 }