src/ipc/Inquirer.h

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 54    Interprocess Communication
   5  *
   6  */
   7
   8 #ifndef SQUID_IPC_INQUIRER_H
   9 #define SQUID_IPC_INQUIRER_H
  10
  11 #include "base/AsyncJobCalls.h"
  12 #include "base/AsyncJob.h"
  13 #include "ipc/forward.h"
  14 #include "ipc/Request.h"
  15 #include "ipc/Response.h"
  16 #include "ipc/StrandCoords.h"
  17 #include <map>
  18
  19 namespace Ipc
  20 {
  21
  22 /// Coordinator's job that sends a cache manage request to each strand,
  23 /// aggregating individual strand responses and dumping the result if needed
  24 class Inquirer: public AsyncJob
  25 {
  26 public:
  27     Inquirer(Request::Pointer aRequest, const Ipc::StrandCoords& coords, double aTimeout);
  28     virtual ~Inquirer();
  29
  30     /// finds and calls the right Inquirer upon strand's response
  31     static void HandleRemoteAck(const Response& response);
  32
  33     /* has-to-be-public AsyncJob API */
  34     virtual void callException(const std::exception& e);
  35
  36 protected:
  37     /* AsyncJob API */
  38     virtual void start();
  39     virtual void swanSong();
  40     virtual bool doneAll() const;
  41     virtual const char *status() const;
  42
  43     /// inquire the next strand
  44     virtual void inquire();
  45     /// perform cleanup actions on completion of job
  46     virtual void cleanup();
  47     /// do specific exception handling
  48     virtual void handleException(const std::exception& e);
  49     /// send response to client
  50     virtual void sendResponse() = 0;
  51     /// perform aggregating of responses and returns true if need to continue
  52     virtual bool aggregate(Response::Pointer aResponse) = 0;
  53
  54 private:
  55     typedef UnaryMemFunT<Inquirer, Response::Pointer, Response::Pointer> HandleAckDialer;
  56
  57     void handleRemoteAck(Response::Pointer response);
  58
  59     static AsyncCall::Pointer DequeueRequest(unsigned int requestId);
  60
  61     static void RequestTimedOut(void* param);
  62     void requestTimedOut();
  63     void removeTimeoutEvent();
  64
  65 protected:
  66     Request::Pointer request; ///< cache manager request received from client
  67
  68     Ipc::StrandCoords strands; ///< all strands we want to query, in order
  69     Ipc::StrandCoords::const_iterator pos; ///< strand we should query now
  70
  71     const double timeout; ///< number of seconds to wait for strand response
  72
  73     /// maps request->id to Inquirer::handleRemoteAck callback
  74     typedef std::map<unsigned int, AsyncCall::Pointer> RequestsMap;
  75     static RequestsMap TheRequestsMap; ///< pending strand requests
  76
  77     static unsigned int LastRequestId; ///< last requestId used
  78
  79     CBDATA_CLASS2(Inquirer);
  80 };
  81
  82 } // namespace Ipc
  83
  84 #endif /* SQUID_IPC_INQUIRER_H */