ceph/src/librbd/cache/rwl/SyncPoint.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_CACHE_RWL_SYNC_POINT_H
   5 #define CEPH_LIBRBD_CACHE_RWL_SYNC_POINT_H
   6
   7 #include "librbd/ImageCtx.h"
   8 #include "librbd/cache/rwl/LogEntry.h"
   9 #include "librbd/cache/rwl/Types.h"
  10
  11 namespace librbd {
  12 namespace cache {
  13 namespace rwl {
  14
  15 class SyncPoint {
  16 public:
  17   std::shared_ptr<SyncPointLogEntry> log_entry;
  18   /* Use lock for earlier/later links */
  19   std::shared_ptr<SyncPoint> earlier_sync_point; /* NULL if earlier has completed */
  20   std::shared_ptr<SyncPoint> later_sync_point;
  21   uint64_t final_op_sequence_num = 0;
  22   /* A sync point can't appear in the log until all the writes bearing
  23    * it and all the prior sync points have been appended and
  24    * persisted.
  25    *
  26    * Writes bearing this sync gen number and the prior sync point will be
  27    * sub-ops of this Gather. This sync point will not be appended until all
  28    * these complete to the point where their persist order is guaranteed. */
  29   C_Gather *prior_log_entries_persisted;
  30   int prior_log_entries_persisted_result = 0;
  31   int prior_log_entries_persisted_complete = false;
  32   /* The finisher for this will append the sync point to the log.  The finisher
  33    * for m_prior_log_entries_persisted will be a sub-op of this. */
  34   C_Gather *sync_point_persist;
  35   bool append_scheduled = false;
  36   bool appending = false;
  37   /* Signal these when this sync point is appending to the log, and its order
  38    * of appearance is guaranteed. One of these is is a sub-operation of the
  39    * next sync point's m_prior_log_entries_persisted Gather. */
  40   std::vector<Context*> on_sync_point_appending;
  41   /* Signal these when this sync point is appended and persisted. User
  42    * aio_flush() calls are added to this. */
  43   std::vector<Context*> on_sync_point_persisted;
  44
  45   SyncPoint(uint64_t sync_gen_num, CephContext *cct);
  46   ~SyncPoint();
  47   SyncPoint(const SyncPoint&) = delete;
  48   SyncPoint &operator=(const SyncPoint&) = delete;
  49
  50 private:
  51   CephContext *m_cct;
  52   friend std::ostream &operator<<(std::ostream &os,
  53                                   const SyncPoint &p);
  54 };
  55
  56 } // namespace rwl
  57 } // namespace cache
  58 } // namespace librbd
  59
  60 #endif // CEPH_LIBRBD_CACHE_RWL_SYNC_POINT_H