src/ceph/src/librbd/watcher/RewatchRequest.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #ifndef CEPH_LIBRBD_WATCHER_REWATCH_REQUEST_H
   5 #define CEPH_LIBRBD_WATCHER_REWATCH_REQUEST_H
   6
   7 #include "include/int_types.h"
   8 #include "include/rados/librados.hpp"
   9
  10 struct Context;
  11 struct RWLock;
  12
  13 namespace librbd {
  14
  15 namespace watcher {
  16
  17 class RewatchRequest {
  18 public:
  19
  20   static RewatchRequest *create(librados::IoCtx& ioctx, const std::string& oid,
  21                                 RWLock &watch_lock,
  22                                 librados::WatchCtx2 *watch_ctx,
  23                                 uint64_t *watch_handle, Context *on_finish) {
  24     return new RewatchRequest(ioctx, oid, watch_lock, watch_ctx, watch_handle,
  25                               on_finish);
  26   }
  27
  28   RewatchRequest(librados::IoCtx& ioctx, const std::string& oid,
  29                  RWLock &watch_lock, librados::WatchCtx2 *watch_ctx,
  30                  uint64_t *watch_handle, Context *on_finish);
  31
  32   void send();
  33
  34 private:
  35   /**
  36    * @verbatim
  37    *
  38    * <start>
  39    *    |
  40    *    v
  41    * UNWATCH
  42    *    |
  43    *    |  . . . .
  44    *    |  .     . (recoverable error)
  45    *    v  v     .
  46    * REWATCH . . .
  47    *    |
  48    *    v
  49    * <finish>
  50    *
  51    * @endverbatim
  52    */
  53
  54   librados::IoCtx& m_ioctx;
  55   std::string m_oid;
  56   RWLock &m_watch_lock;
  57   librados::WatchCtx2 *m_watch_ctx;
  58   uint64_t *m_watch_handle;
  59   Context *m_on_finish;
  60
  61   uint64_t m_rewatch_handle = 0;
  62
  63   void unwatch();
  64   void handle_unwatch(int r);
  65
  66   void rewatch();
  67   void handle_rewatch(int r);
  68
  69   void finish(int r);
  70 };
  71
  72 } // namespace watcher
  73 } // namespace librbd
  74
  75 #endif // CEPH_LIBRBD_WATCHER_REWATCH_REQUEST_H