1 files changed, 69 insertions, 0 deletions
diff --git a/src/librbd/cache/pwl/SyncPoint.h b/src/librbd/cache/pwl/SyncPoint.h
new file mode 100644
index 000000000..424e3730e
--- /dev/null
+++ b/src/librbd/cache/pwl/SyncPoint.h
@@ -0,0 +1,69 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_CACHE_RWL_SYNC_POINT_H
+#define CEPH_LIBRBD_CACHE_RWL_SYNC_POINT_H 
+
+#include "librbd/ImageCtx.h"
+#include "librbd/cache/pwl/LogEntry.h"
+#include "librbd/cache/pwl/Types.h"
+
+namespace librbd {
+namespace cache {
+namespace pwl {
+
+class SyncPoint: public std::enable_shared_from_this<SyncPoint> {
+public:
+  std::shared_ptr<SyncPointLogEntry> log_entry;
+  /* Use lock for earlier/later links */
+  std::shared_ptr<SyncPoint> earlier_sync_point; /* NULL if earlier has completed */
+  std::shared_ptr<SyncPoint> later_sync_point;
+  bool appending = false;
+  /* Signal these when this sync point is appending to the log, and its order
+   * of appearance is guaranteed. One of these is is a sub-operation of the
+   * next sync point's m_prior_log_entries_persisted Gather. */
+  std::vector<Context*> on_sync_point_appending;
+  /* Signal these when this sync point is appended and persisted. User
+   * aio_flush() calls are added to this. */
+  std::vector<Context*> on_sync_point_persisted;
+
+  SyncPoint(uint64_t sync_gen_num, CephContext *cct);
+  ~SyncPoint();
+  SyncPoint(const SyncPoint&) = delete;
+  SyncPoint &operator=(const SyncPoint&) = delete;
+  void persist_gather_activate();
+  Context* persist_gather_new_sub();
+  void persist_gather_set_finisher(Context *ctx);
+  void prior_persisted_gather_activate();
+  Context* prior_persisted_gather_new_sub();
+  void prior_persisted_gather_set_finisher();
+  void add_in_on_persisted_ctxs(Context* cxt);
+  void add_in_on_appending_ctxs(Context* cxt);
+  void setup_earlier_sync_point(std::shared_ptr<SyncPoint> sync_point,
+                                uint64_t last_op_sequence_num);
+private:
+  CephContext *m_cct;
+  bool m_append_scheduled = false;
+  uint64_t m_final_op_sequence_num = 0;
+  /* A sync point can't appear in the log until all the writes bearing
+   * it and all the prior sync points have been appended and
+   * persisted.
+   *
+   * Writes bearing this sync gen number and the prior sync point will be
+   * sub-ops of this Gather. This sync point will not be appended until all
+   * these complete to the point where their persist order is guaranteed. */
+  C_Gather *m_prior_log_entries_persisted;
+  /* The finisher for this will append the sync point to the log.  The finisher
+   * for m_prior_log_entries_persisted will be a sub-op of this. */
+  C_Gather *m_sync_point_persist;
+  int m_prior_log_entries_persisted_result = 0;
+  int m_prior_log_entries_persisted_complete = false;
+  friend std::ostream &operator<<(std::ostream &os,
+                                  const SyncPoint &p);
+};
+
+} // namespace pwl
+} // namespace cache
+} // namespace librbd
+
+#endif // CEPH_LIBRBD_CACHE_RWL_SYNC_POINT_H