pdns/selectmplexer.cc

   1 #ifdef HAVE_CONFIG_H
   2 #include "config.h"
   3 #endif
   4 #include "mplexer.hh"
   5 #include "sstuff.hh"
   6 #include <iostream>
   7 #include "misc.hh"
   8
   9 #include "namespaces.hh"
  10
  11 static FDMultiplexer* make()
  12 {
  13   return new SelectFDMultiplexer();
  14 }
  15
  16 static struct RegisterOurselves
  17 {
  18   RegisterOurselves() {
  19     FDMultiplexer::getMultiplexerMap().insert(make_pair(1, &make));
  20   }
  21 } doIt;
  22
  23 void SelectFDMultiplexer::addFD(callbackmap_t& cbmap, int fd, callbackfunc_t toDo, const boost::any& parameter)
  24 {
  25   Callback cb;
  26   cb.d_callback=toDo;
  27   cb.d_parameter=parameter;
  28   memset(&cb.d_ttd, 0, sizeof(cb.d_ttd));
  29   if(cbmap.count(fd))
  30     throw FDMultiplexerException("Tried to add fd "+std::to_string(fd)+ " to multiplexer twice");
  31   cbmap[fd]=cb;
  32 }
  33
  34 void SelectFDMultiplexer::removeFD(callbackmap_t& cbmap, int fd)
  35 {
  36   if(d_inrun && d_iter->first==fd)  // trying to remove us!
  37     d_iter++;
  38
  39   if(!cbmap.erase(fd))
  40     throw FDMultiplexerException("Tried to remove unlisted fd "+std::to_string(fd)+ " from multiplexer");
  41 }
  42
  43 int SelectFDMultiplexer::run(struct timeval* now, int timeout)
  44 {
  45   if(d_inrun) {
  46     throw FDMultiplexerException("FDMultiplexer::run() is not reentrant!\n");
  47   }
  48   fd_set readfds, writefds;
  49   FD_ZERO(&readfds);
  50   FD_ZERO(&writefds);
  51
  52   int fdmax=0;
  53
  54   for(callbackmap_t::const_iterator i=d_readCallbacks.begin(); i != d_readCallbacks.end(); ++i) {
  55     FD_SET(i->first, &readfds);
  56     fdmax=max(i->first, fdmax);
  57   }
  58
  59   for(callbackmap_t::const_iterator i=d_writeCallbacks.begin(); i != d_writeCallbacks.end(); ++i) {
  60     FD_SET(i->first, &writefds);
  61     fdmax=max(i->first, fdmax);
  62   }
  63
  64   struct timeval tv={timeout / 1000 , (timeout % 1000) * 1000};
  65   int ret=select(fdmax + 1, &readfds, &writefds, 0, &tv);
  66   gettimeofday(now, 0); // MANDATORY!
  67
  68   if(ret < 0 && errno!=EINTR)
  69     throw FDMultiplexerException("select returned error: "+stringerror());
  70
  71   if(ret < 1) // nothing - thanks AB
  72     return 0;
  73
  74   d_iter=d_readCallbacks.end();
  75   d_inrun=true;
  76
  77   int got = 0;
  78   for(callbackmap_t::iterator i=d_readCallbacks.begin(); i != d_readCallbacks.end() && i->first <= fdmax; ) {
  79     d_iter=i++;
  80
  81     if(FD_ISSET(d_iter->first, &readfds)) {
  82       d_iter->second.d_callback(d_iter->first, d_iter->second.d_parameter);
  83       got++;
  84       continue;  // so we don't refind ourselves as writable
  85     }
  86   }
  87
  88   for(callbackmap_t::iterator i=d_writeCallbacks.begin(); i != d_writeCallbacks.end() && i->first <= fdmax; ) {
  89     d_iter=i++;
  90     if(FD_ISSET(d_iter->first, &writefds)) {
  91       d_iter->second.d_callback(d_iter->first, d_iter->second.d_parameter);
  92       got++;
  93     }
  94   }
  95
  96   d_inrun=false;
  97   return got;
  98 }
  99
 100 #if 0
 101
 102 void acceptData(int fd, boost::any& parameter)
 103 {
 104   cout<<"Have data on fd "<<fd<<endl;
 105   Socket* sock=boost::any_cast<Socket*>(parameter);
 106   string packet;
 107   IPEndpoint rem;
 108   sock->recvFrom(packet, rem);
 109   cout<<"Received "<<packet.size()<<" bytes!\n";
 110 }
 111
 112
 113 int main()
 114 {
 115   Socket s(AF_INET, SOCK_DGRAM);
 116
 117   IPEndpoint loc("0.0.0.0", 2000);
 118   s.bind(loc);
 119
 120   SelectFDMultiplexer sfm;
 121
 122   sfm.addReadFD(s.getHandle(), &acceptData, &s);
 123
 124   for(int n=0; n < 100 ; ++n) {
 125     sfm.run();
 126   }
 127   sfm.removeReadFD(s.getHandle());
 128   sfm.removeReadFD(s.getHandle());
 129 }
 130 #endif
 131