initial code repo

[stor4nfv.git] / src / ceph / src / librbd / Watcher.h

diff --git a/src/ceph/src/librbd/Watcher.h b/src/ceph/src/librbd/Watcher.h
new file mode 100644 (file)
index 0000000..3900902
--- /dev/null
+++ b/src/ceph/src/librbd/Watcher.h
@@ -0,0 +1,169 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_WATCHER_H
+#define CEPH_LIBRBD_WATCHER_H
+
+#include "common/AsyncOpTracker.h"
+#include "common/Mutex.h"
+#include "common/RWLock.h"
+#include "include/rados/librados.hpp"
+#include "librbd/watcher/Notifier.h"
+#include "librbd/watcher/Types.h"
+#include <string>
+#include <utility>
+
+class ContextWQ;
+
+namespace librbd {
+
+namespace watcher { struct NotifyResponse; }
+
+class Watcher {
+public:
+  struct C_NotifyAck : public Context {
+    Watcher *watcher;
+    CephContext *cct;
+    uint64_t notify_id;
+    uint64_t handle;
+    bufferlist out;
+
+    C_NotifyAck(Watcher *watcher, uint64_t notify_id, uint64_t handle);
+    void finish(int r) override;
+  };
+
+  Watcher(librados::IoCtx& ioctx, ContextWQ *work_queue,
+          const std::string& oid);
+  virtual ~Watcher();
+
+  void register_watch(Context *on_finish);
+  virtual void unregister_watch(Context *on_finish);
+  void flush(Context *on_finish);
+
+  bool notifications_blocked() const;
+  virtual void block_notifies(Context *on_finish);
+  void unblock_notifies();
+
+  std::string get_oid() const;
+  void set_oid(const string& oid);
+
+  uint64_t get_watch_handle() const {
+    RWLock::RLocker watch_locker(m_watch_lock);
+    return m_watch_handle;
+  }
+
+  bool is_registered() const {
+    RWLock::RLocker locker(m_watch_lock);
+    return m_watch_state == WATCH_STATE_REGISTERED;
+  }
+  bool is_unregistered() const {
+    RWLock::RLocker locker(m_watch_lock);
+    return m_watch_state == WATCH_STATE_UNREGISTERED;
+  }
+
+protected:
+  enum WatchState {
+    WATCH_STATE_UNREGISTERED,
+    WATCH_STATE_REGISTERING,
+    WATCH_STATE_REGISTERED,
+    WATCH_STATE_ERROR,
+    WATCH_STATE_REWATCHING
+  };
+
+  librados::IoCtx& m_ioctx;
+  ContextWQ *m_work_queue;
+  std::string m_oid;
+  CephContext *m_cct;
+  mutable RWLock m_watch_lock;
+  uint64_t m_watch_handle;
+  watcher::Notifier m_notifier;
+  WatchState m_watch_state;
+  AsyncOpTracker m_async_op_tracker;
+
+  void send_notify(bufferlist &payload,
+                   watcher::NotifyResponse *response = nullptr,
+                   Context *on_finish = nullptr);
+
+  virtual void handle_notify(uint64_t notify_id, uint64_t handle,
+                             uint64_t notifier_id, bufferlist &bl) = 0;
+
+  virtual void handle_error(uint64_t cookie, int err);
+
+  void acknowledge_notify(uint64_t notify_id, uint64_t handle,
+                          bufferlist &out);
+
+  virtual void handle_rewatch_complete(int r) { }
+
+private:
+  /**
+   * @verbatim
+   *
+   * <start>
+   *    |
+   *    v
+   * UNREGISTERED
+   *    |
+   *    | (register_watch)
+   *    |
+   * REGISTERING
+   *    |
+   *    v      (watch error)
+   * REGISTERED * * * * * * * > ERROR
+   *    |   ^                     |
+   *    |   |                     | (rewatch)
+   *    |   |                     v
+   *    |   |                   REWATCHING
+   *    |   |                     |
+   *    |   |                     |
+   *    |   \---------------------/
+   *    |
+   *    | (unregister_watch)
+   *    |
+   *    v
+   * UNREGISTERED
+   *    |
+   *    v
+   * <finish>
+   *
+   * @endverbatim
+   */
+
+  struct WatchCtx : public librados::WatchCtx2 {
+    Watcher &watcher;
+
+    WatchCtx(Watcher &parent) : watcher(parent) {}
+
+    void handle_notify(uint64_t notify_id,
+                       uint64_t handle,
+                       uint64_t notifier_id,
+                       bufferlist& bl) override;
+    void handle_error(uint64_t handle, int err) override;
+  };
+
+  struct C_RegisterWatch : public Context {
+    Watcher *watcher;
+    Context *on_finish;
+
+    C_RegisterWatch(Watcher *watcher, Context *on_finish)
+       : watcher(watcher), on_finish(on_finish) {
+    }
+    void finish(int r) override {
+      watcher->handle_register_watch(r, on_finish);
+    }
+  };
+
+  WatchCtx m_watch_ctx;
+  Context *m_unregister_watch_ctx = nullptr;
+
+  uint32_t m_blocked_count = 0;
+
+  void handle_register_watch(int r, Context *on_finish);
+
+  void rewatch();
+  void handle_rewatch(int r);
+
+};
+
+} // namespace librbd
+
+#endif // CEPH_LIBRBD_WATCHER_H