src/ipc/Coordinator.cc

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 54    Interprocess Communication
   5  *
   6  */
   7
   8
   9 #include "config.h"
  10 #include "base/TextException.h"
  11 #include "CacheManager.h"
  12 #include "comm.h"
  13 #include "ipc/Coordinator.h"
  14 #include "ipc/FdNotes.h"
  15 #include "ipc/SharedListen.h"
  16 #include "mgr/Inquirer.h"
  17 #include "mgr/Request.h"
  18 #include "mgr/Response.h"
  19 #include "mgr/StoreToCommWriter.h"
  20
  21
  22 CBDATA_NAMESPACED_CLASS_INIT(Ipc, Coordinator);
  23 Ipc::Coordinator* Ipc::Coordinator::TheInstance = NULL;
  24
  25
  26 Ipc::Coordinator::Coordinator():
  27         Port(coordinatorAddr)
  28 {
  29 }
  30
  31 void Ipc::Coordinator::start()
  32 {
  33     Port::start();
  34 }
  35
  36 Ipc::StrandCoord* Ipc::Coordinator::findStrand(int kidId)
  37 {
  38     typedef StrandCoords::iterator SI;
  39     for (SI iter = strands_.begin(); iter != strands_.end(); ++iter) {
  40         if (iter->kidId == kidId)
  41             return &(*iter);
  42     }
  43     return NULL;
  44 }
  45
  46 void Ipc::Coordinator::registerStrand(const StrandCoord& strand)
  47 {
  48     debugs(54, 3, HERE << "registering kid" << strand.kidId <<
  49            ' ' << strand.tag);
  50     if (StrandCoord* found = findStrand(strand.kidId)) {
  51         const String oldTag = found->tag;
  52         *found = strand;
  53         if (oldTag.size() && !strand.tag.size())
  54             found->tag = oldTag; // keep more detailed info (XXX?)
  55     } else {
  56         strands_.push_back(strand);
  57     }
  58
  59     // notify searchers waiting for this new strand, if any
  60     typedef Searchers::iterator SRI;
  61     for (SRI i = searchers.begin(); i != searchers.end();) {
  62         if (i->tag == strand.tag) {
  63             notifySearcher(*i, strand);
  64             i = searchers.erase(i);
  65                 } else {
  66             ++i;
  67                 }
  68     }
  69 }
  70
  71 void Ipc::Coordinator::receive(const TypedMsgHdr& message)
  72 {
  73     switch (message.type()) {
  74     case mtRegistration:
  75         debugs(54, 6, HERE << "Registration request");
  76         handleRegistrationRequest(HereIamMessage(message));
  77         break;
  78
  79     case mtStrandSearchRequest: {
  80         const StrandSearchRequest sr(message);
  81         debugs(54, 6, HERE << "Strand search request: " << sr.requestorId <<
  82                " tag: " << sr.tag);
  83         handleSearchRequest(sr);
  84         break;
  85     }
  86
  87     case mtSharedListenRequest:
  88         debugs(54, 6, HERE << "Shared listen request");
  89         handleSharedListenRequest(SharedListenRequest(message));
  90         break;
  91
  92     case mtCacheMgrRequest:
  93         debugs(54, 6, HERE << "Cache manager request");
  94         handleCacheMgrRequest(Mgr::Request(message));
  95         break;
  96
  97     case mtCacheMgrResponse:
  98         debugs(54, 6, HERE << "Cache manager response");
  99         handleCacheMgrResponse(Mgr::Response(message));
 100         break;
 101
 102     default:
 103         debugs(54, 1, HERE << "Unhandled message type: " << message.type());
 104         break;
 105     }
 106 }
 107
 108 void Ipc::Coordinator::handleRegistrationRequest(const HereIamMessage& msg)
 109 {
 110     registerStrand(msg.strand);
 111
 112     // send back an acknowledgement; TODO: remove as not needed?
 113     TypedMsgHdr message;
 114     msg.pack(message);
 115     SendMessage(MakeAddr(strandAddrPfx, msg.strand.kidId), message);
 116 }
 117
 118 void
 119 Ipc::Coordinator::handleSharedListenRequest(const SharedListenRequest& request)
 120 {
 121     debugs(54, 4, HERE << "kid" << request.requestorId <<
 122            " needs shared listen FD for " << request.params.addr);
 123     Listeners::const_iterator i = listeners.find(request.params);
 124     int errNo = 0;
 125     const int sock = (i != listeners.end()) ?
 126                      i->second : openListenSocket(request, errNo);
 127
 128     debugs(54, 3, HERE << "sending shared listen FD " << sock << " for " <<
 129            request.params.addr << " to kid" << request.requestorId <<
 130            " mapId=" << request.mapId);
 131
 132     SharedListenResponse response(sock, errNo, request.mapId);
 133     TypedMsgHdr message;
 134     response.pack(message);
 135     SendMessage(MakeAddr(strandAddrPfx, request.requestorId), message);
 136 }
 137
 138 void
 139 Ipc::Coordinator::handleCacheMgrRequest(const Mgr::Request& request)
 140 {
 141     debugs(54, 4, HERE);
 142
 143     // Let the strand know that we are now responsible for handling the request
 144     Mgr::Response response(request.requestId);
 145     TypedMsgHdr message;
 146     response.pack(message);
 147     SendMessage(MakeAddr(strandAddrPfx, request.requestorId), message);
 148
 149     Mgr::Action::Pointer action =
 150         CacheManager::GetInstance()->createRequestedAction(request.params);
 151     AsyncJob::Start(new Mgr::Inquirer(action,
 152                                       Mgr::ImportHttpFdIntoComm(request.fd), request, strands_));
 153 }
 154
 155 void
 156 Ipc::Coordinator::handleCacheMgrResponse(const Mgr::Response& response)
 157 {
 158     Mgr::Inquirer::HandleRemoteAck(response);
 159 }
 160
 161 void
 162 Ipc::Coordinator::handleSearchRequest(const Ipc::StrandSearchRequest &request)
 163 {
 164     // do we know of a strand with the given search tag?
 165     const StrandCoord *strand = NULL;
 166     typedef StrandCoords::const_iterator SCCI;
 167     for (SCCI i = strands_.begin(); !strand && i != strands_.end(); ++i) {
 168         if (i->tag == request.tag)
 169             strand = &(*i);
 170     }
 171
 172     if (strand) {
 173         notifySearcher(request, *strand);
 174         return;
 175         }
 176
 177     searchers.push_back(request);
 178     debugs(54, 3, HERE << "cannot yet tell kid" << request.requestorId <<
 179         " who " << request.tag << " is");
 180 }
 181
 182 void
 183 Ipc::Coordinator::notifySearcher(const Ipc::StrandSearchRequest &request,
 184                                  const StrandCoord& strand)
 185 {
 186     debugs(54, 3, HERE << "tell kid" << request.requestorId << " that " <<
 187         request.tag << " is kid" << strand.kidId);
 188     const StrandSearchResponse response(strand);
 189     TypedMsgHdr message;
 190     response.pack(message);
 191     SendMessage(MakeAddr(strandAddrPfx, request.requestorId), message);
 192 }
 193
 194
 195 int
 196 Ipc::Coordinator::openListenSocket(const SharedListenRequest& request,
 197                                    int &errNo)
 198 {
 199     const OpenListenerParams &p = request.params;
 200
 201     debugs(54, 6, HERE << "opening listen FD at " << p.addr << " for kid" <<
 202            request.requestorId);
 203
 204     Ip::Address addr = p.addr; // comm_open_listener may modify it
 205
 206     enter_suid();
 207     const int sock = comm_open_listener(p.sock_type, p.proto, addr, p.flags,
 208                                         FdNote(p.fdNote));
 209     errNo = (sock >= 0) ? 0 : errno;
 210     leave_suid();
 211
 212     // cache positive results
 213     if (sock >= 0)
 214         listeners[request.params] = sock;
 215
 216     return sock;
 217 }
 218
 219 void Ipc::Coordinator::broadcastSignal(int sig) const
 220 {
 221     typedef StrandCoords::const_iterator SCI;
 222     for (SCI iter = strands_.begin(); iter != strands_.end(); ++iter) {
 223         debugs(54, 5, HERE << "signal " << sig << " to kid" << iter->kidId <<
 224                ", PID=" << iter->pid);
 225         kill(iter->pid, sig);
 226     }
 227 }
 228
 229 Ipc::Coordinator* Ipc::Coordinator::Instance()
 230 {
 231     if (!TheInstance)
 232         TheInstance = new Coordinator;
 233     // XXX: if the Coordinator job quits, this pointer will become invalid
 234     // we could make Coordinator death fatal, except during exit, but since
 235     // Strands do not re-register, even process death would be pointless.
 236     return TheInstance;
 237 }
 238
 239 const Ipc::StrandCoords&
 240 Ipc::Coordinator::strands() const
 241 {
 242     return strands_;
 243 }