src/ipc/Forwarder.h

   1 /*
   2  * Copyright (C) 1996-2020 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_FORWARDER_H
  12 #define SQUID_IPC_FORWARDER_H
  13
  14 #include "base/AsyncJob.h"
  15 #include "cbdata.h"
  16 #include "ipc/Request.h"
  17 #include "mgr/ActionParams.h"
  18
  19 #include <map>
  20
  21 namespace Ipc
  22 {
  23
  24 /** Forwards a worker request to coordinator.
  25  * Waits for an ACK from Coordinator
  26  * Send the data unit with an error response if forwarding fails.
  27  */
  28 class Forwarder: public AsyncJob
  29 {
  30     CBDATA_CLASS(Forwarder);
  31
  32 public:
  33     Forwarder(Request::Pointer aRequest, double aTimeout);
  34     virtual ~Forwarder();
  35
  36     /// finds and calls the right Forwarder upon Coordinator's response
  37     static void HandleRemoteAck(unsigned int requestId);
  38
  39     /* has-to-be-public AsyncJob API */
  40     virtual void callException(const std::exception& e);
  41
  42 protected:
  43     /* AsyncJob API */
  44     virtual void start();
  45     virtual void swanSong();
  46     virtual bool doneAll() const;
  47
  48     virtual void handleError();
  49     virtual void handleTimeout();
  50     virtual void handleException(const std::exception& e);
  51
  52 private:
  53     static void RequestTimedOut(void* param);
  54     void requestTimedOut();
  55     void removeTimeoutEvent();
  56
  57     void handleRemoteAck();
  58
  59     static AsyncCall::Pointer DequeueRequest(unsigned int requestId);
  60
  61 protected:
  62     Request::Pointer request;
  63     const double timeout; ///< response wait timeout in seconds
  64
  65     /// maps request->id to Forwarder::handleRemoteAck callback
  66     typedef std::map<unsigned int, AsyncCall::Pointer> RequestsMap;
  67     static RequestsMap TheRequestsMap; ///< pending Coordinator requests
  68
  69     static unsigned int LastRequestId; ///< last requestId used
  70 };
  71
  72 } // namespace Ipc
  73
  74 #endif /* SQUID_IPC_FORWARDER_H */
  75