src/ipc/Coordinator.h

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 54    Interprocess Communication */
  10
  11 #ifndef SQUID_IPC_COORDINATOR_H
  12 #define SQUID_IPC_COORDINATOR_H
  13
  14 #include "ipc/Messages.h"
  15 #include "ipc/Port.h"
  16 #include "ipc/SharedListen.h"
  17 #include "ipc/StrandCoords.h"
  18 #include "ipc/StrandSearch.h"
  19 #include "mgr/forward.h"
  20 #if SQUID_SNMP
  21 #include "snmp/forward.h"
  22 #endif
  23 #include <list>
  24 #include <map>
  25
  26 namespace Ipc
  27 {
  28
  29 ///  Coordinates shared activities of Strands (Squid processes or threads)
  30 class Coordinator: public Port
  31 {
  32     CBDATA_CLASS(Coordinator);
  33
  34 public:
  35     static Coordinator* Instance();
  36
  37 public:
  38     Coordinator();
  39
  40     void broadcastSignal(int sig) const; ///< send sig to registered strands
  41
  42     const StrandCoords &strands() const; ///< currently registered strands
  43
  44 protected:
  45     virtual void start(); // Port (AsyncJob) API
  46     virtual void receive(const TypedMsgHdr& message); // Port API
  47
  48     StrandCoord* findStrand(int kidId); ///< registered strand or NULL
  49     void registerStrand(const StrandCoord &); ///< adds or updates existing
  50     void handleRegistrationRequest(const HereIamMessage &); ///< register,ACK
  51
  52     /// answer the waiting search request
  53     void notifySearcher(const StrandSearchRequest &request, const StrandCoord&);
  54     /// answers or queues the request if the answer is not yet known
  55     void handleSearchRequest(const StrandSearchRequest &request);
  56
  57     /// returns cached socket or calls openListenSocket()
  58     void handleSharedListenRequest(const SharedListenRequest& request);
  59     void handleCacheMgrRequest(const Mgr::Request& request);
  60     void handleCacheMgrResponse(const Mgr::Response& response);
  61 #if SQUID_SNMP
  62     void handleSnmpRequest(const Snmp::Request& request);
  63     void handleSnmpResponse(const Snmp::Response& response);
  64 #endif
  65     /// calls comm_open_listener()
  66     Comm::ConnectionPointer openListenSocket(const SharedListenRequest& request, int &errNo);
  67
  68 private:
  69     StrandCoords strands_; ///< registered processes and threads
  70
  71     typedef std::list<StrandSearchRequest> Searchers; ///< search requests
  72     Searchers searchers; ///< yet unanswered search requests in arrival order
  73
  74     typedef std::map<OpenListenerParams, Comm::ConnectionPointer> Listeners; ///< params:connection map
  75     Listeners listeners; ///< cached comm_open_listener() results
  76
  77     static Coordinator* TheInstance; ///< the only class instance in existence
  78
  79 private:
  80     Coordinator(const Coordinator&); // not implemented
  81     Coordinator& operator =(const Coordinator&); // not implemented
  82 };
  83
  84 } // namespace Ipc
  85
  86 #endif /* SQUID_IPC_COORDINATOR_H */
  87