pdns/communicator.cc

   1 /*
   2     PowerDNS Versatile Database Driven Nameserver
   3     Copyright (C) 2002-2009  PowerDNS.COM BV
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License version 2 as
   7     published by the Free Software Foundation;
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18 #include "packetcache.hh"
  19 #include "utility.hh"
  20 #include <errno.h>
  21 #include "communicator.hh"
  22 #include <set>
  23 #include <boost/utility.hpp>
  24 #include "dnsbackend.hh"
  25 #include "ueberbackend.hh"
  26 #include "packethandler.hh"
  27 #include "resolver.hh"
  28 #include "logger.hh"
  29 #include "dns.hh"
  30 #include "arguments.hh"
  31 #include "session.hh"
  32 #include "packetcache.hh"
  33 #include <boost/lexical_cast.hpp>
  34
  35 #include "namespaces.hh"
  36
  37
  38 void CommunicatorClass::mainloop(void)
  39 {
  40   try {
  41 #ifndef WIN32
  42     signal(SIGPIPE,SIG_IGN);
  43 #endif // WIN32
  44     L<<Logger::Error<<"Master/slave communicator launching"<<endl;
  45     PacketHandler P;
  46     d_tickinterval=::arg().asNum("slave-cycle-interval");
  47     makeNotifySocket();
  48
  49     int rc;
  50     time_t next;
  51
  52     time_t tick;
  53
  54     for(;;) {
  55       slaveRefresh(&P);
  56       masterUpdateCheck(&P);
  57       tick=doNotifications();
  58
  59       tick = min (tick, d_tickinterval);
  60
  61       //      L<<Logger::Error<<"tick = "<<tick<<", d_tickinterval = "<<d_tickinterval<<endl;
  62       next=time(0)+tick;
  63
  64       while(time(0) < next) {
  65         rc=d_any_sem.tryWait();
  66
  67         if(rc)
  68           Utility::sleep(1);
  69         else {
  70           if(!d_suck_sem.tryWait()) {
  71             SuckRequest sr;
  72             {
  73               Lock l(&d_lock);
  74               sr=d_suckdomains.front();
  75               d_suckdomains.pop_front();
  76             }
  77             suck(sr.domain,sr.master);
  78           }
  79         }
  80         // this gets executed at least once every second
  81         doNotifications();
  82       }
  83     }
  84   }
  85   catch(AhuException &ae) {
  86     L<<Logger::Error<<"Communicator thread died because of error: "<<ae.reason<<endl;
  87     Utility::sleep(1);
  88     exit(0);
  89   }
  90   catch(std::exception &e) {
  91     L<<Logger::Error<<"Communicator thread died because of STL error: "<<e.what()<<endl;
  92     exit(0);
  93   }
  94   catch( ... )
  95   {
  96     L << Logger::Error << "Communicator caught unknown exception." << endl;
  97     exit( 0 );
  98   }
  99 }
 100