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_config.h"
  18 #include "globals.h"
  19 #include "inspircd.h"
  20 #include <vector>
  21 #include <string>
  22 #include <sys/select.h>
  23 #include "socketengine_select.h"
  24
  25
  26 SelectEngine::SelectEngine(InspIRCd* Instance) : SocketEngine(Instance)
  27 {
  28         ServerInstance->Log(DEBUG,"SelectEngine::SelectEngine()");
  29         EngineHandle = 0;
  30         CurrentSetSize = 0;
  31 }
  32
  33 SelectEngine::~SelectEngine()
  34 {
  35         ServerInstance->Log(DEBUG,"SelectEngine::~SelectEngine()");
  36 }
  37
  38 bool SelectEngine::AddFd(EventHandler* eh)
  39 {
  40         int fd = eh->GetFd();
  41         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  42         {
  43                 ServerInstance->Log(DEFAULT,"ERROR: FD of %d added above max of %d",fd,MAX_DESCRIPTORS);
  44                 return false;
  45         }
  46         if (GetRemainingFds() <= 1)
  47         {
  48                 ServerInstance->Log(DEFAULT,"ERROR: System out of file descriptors!");
  49                 return false;
  50         }
  51
  52         fds[fd] = fd;
  53
  54         if (ref[fd])
  55                 return false;
  56
  57         ref[fd] = eh;
  58         ServerInstance->Log(DEBUG,"Add socket %d",fd);
  59
  60         CurrentSetSize++;
  61         return true;
  62 }
  63
  64 bool SelectEngine::DelFd(EventHandler* eh)
  65 {
  66         int fd = eh->GetFd();
  67
  68         ServerInstance->Log(DEBUG,"SelectEngine::DelFd(%d)",fd);
  69
  70         if ((fd < 0) || (fd > MAX_DESCRIPTORS))
  71                 return false;
  72
  73         std::map<int,int>::iterator t = fds.find(fd);
  74         if (t != fds.end())
  75         {
  76                 fds.erase(t);
  77                 ServerInstance->Log(DEBUG,"Deleted fd %d",fd);
  78         }
  79
  80         CurrentSetSize--;
  81         ref[fd] = NULL;
  82         return true;
  83 }
  84
  85 int SelectEngine::GetMaxFds()
  86 {
  87         return FD_SETSIZE;
  88 }
  89
  90 int SelectEngine::GetRemainingFds()
  91 {
  92         return FD_SETSIZE - CurrentSetSize;
  93 }
  94
  95 int SelectEngine::DispatchEvents()
  96 {
  97         int result = 0;
  98         timeval tval;
  99         int sresult = 0;
 100         EventHandler* ev[MAX_DESCRIPTOR];
 101
 102         FD_ZERO(&wfdset);
 103         FD_ZERO(&rfdset);
 104
 105         for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 106         {
 107                 if (ref[a->second]->Readable())
 108                 {
 109                         FD_SET (a->second, &rfdset);
 110                 }
 111                 else
 112                 {
 113                         FD_SET (a->second, &wfdset);
 114                 }
 115
 116         }
 117         tval.tv_sec = 0;
 118         tval.tv_usec = 50L;
 119         sresult = select(FD_SETSIZE, &rfdset, &wfdset, NULL, &tval);
 120         if (sresult > 0)
 121         {
 122                 for (std::map<int,int>::iterator a = fds.begin(); a != fds.end(); a++)
 123                 {
 124                         if ((FD_ISSET (a->second, &rfdset)) || (FD_ISSET (a->second, &wfdset)))
 125                         {
 126                                 ev[result++] = ref[a->second];
 127                         }
 128                 }
 129         }
 130
 131         /** An event handler may remove its own descriptor from the list, therefore it is not
 132          * safe to directly iterate over the list and dispatch events there with STL iterators.
 133          * Thats a shame because it makes this code slower and more resource intensive, but maybe
 134          * the user should stop using select(), as select() smells anyway.
 135          */
 136         for (int i = 0; i < result; i++)
 137         {
 138                 ServerInstance->Log(DEBUG,"Handle %s event on fd %d",ev[i]->Readable() ? "read" : "write", ev[i]->GetFd());
 139                 ev[i]->HandleEvent(ev[i]->Readable() ? EVENT_READ : EVENT_WRITE);
 140         }
 141
 142         return result;
 143 }
 144
 145 std::string SelectEngine::GetName()
 146 {
 147         return "select";
 148 }