Repo restructuring

1 files changed, 157 insertions, 0 deletions

diff --git a/TAO/tao/LF_Event.h b/TAO/tao/LF_Event.h
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+// -*- C++ -*-
+
+//=============================================================================
+/**
+ *  @file LF_Event.h
+ *
+ *  $Id$
+ *
+ *  @author Carlos O'Ryan <coryan@uci.edu>
+ */
+//=============================================================================
+
+#ifndef TAO_LF_EVENT_H
+#define TAO_LF_EVENT_H
+
+#include /**/ "ace/pre.h"
+
+#include "tao/TAO_Export.h"
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+# pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+#include "tao/Versioned_Namespace.h"
+
+TAO_BEGIN_VERSIONED_NAMESPACE_DECL
+
+class TAO_LF_Follower;
+class TAO_Leader_Follower;
+
+/**
+ * @class TAO_LF_Event
+ *
+ * @brief Use the Leader/Follower loop to wait for one specific event.
+ *
+ * The Leader/Follower event loop is used to wait for incoming
+ * responses, as well as to wait for all the data to be flushed.
+ * This class encapsulates this event loop. It uses Template Method to
+ * parametrize the 'waited for' predicate (i.e. reply received or
+ * message sent or connection establishment etc.)
+ *
+ * @todo Implementing the Leader/Followers loop in this class, as
+ * well as the callbacks to communicate that an event has completed
+ * leads to excessive coupling.  A better design would use a separate
+ * class to signal the events, that would allow us to remove the
+ * Leader/Followers logic from the ORB.  However, that requires other
+ * major changes and it somewhat complicates the design.
+ *
+ */
+class TAO_Export TAO_LF_Event
+{
+public:
+
+  friend class TAO_Leader_Follower;
+
+  /// Constructor
+  TAO_LF_Event (void);
+
+  /// Destructor
+  virtual ~TAO_LF_Event (void);
+
+  /// Bind a follower
+  /**
+   * An event can be waited on by at most one follower thread, this
+   * method is used to bind the waiting thread to the event, in order
+   * to let the event signal any important state changes.
+   *
+   * This is virtual to allow the LF_Multi_Event derived type share
+   * the follower with all the subordinate LF_CH_Events.
+   *
+   * @return -1 if the LF_Event is already bound, 0 otherwise
+   */
+  virtual int bind (TAO_LF_Follower *follower);
+
+  /// Unbind the follower
+  virtual int unbind (void);
+
+  //@{
+  /** @name State management
+   *
+   * A Leader/Followers event goes through several states during its
+   * lifetime. We use an enum to represent those states and state
+   * changes are validated according to the rules defined in the
+   * concrete classes. We treat the states as finite states in a
+   * FSM. The possible sequence of states through which the FSM
+   * migrates is defined in the concrete classes.
+   */
+  enum {
+    /// The event is created, and is in initial state
+    LFS_IDLE = 0,
+    /// The event is active
+    LFS_ACTIVE,
+    /// The event is waiting for connection completion.
+    LFS_CONNECTION_WAIT,
+    /// The event has completed successfully
+    LFS_SUCCESS,
+    /// A failure has been detected while the event was active
+    LFS_FAILURE,
+    /// The event has timed out
+    LFS_TIMEOUT,
+    /// The connection was closed.
+    LFS_CONNECTION_CLOSED
+  };
+
+  /**
+   * Virtual methods for this class hierarchy..
+   */
+  /// Accessor to change the state. The state isnt changed unless
+  /// certain conditions are satisfied.
+  void state_changed (int new_state,
+                      TAO_Leader_Follower &lf);
+
+  /// Return 1 if the condition was satisfied successfully, 0 if it
+  /// has not
+  virtual int successful (void) const = 0 ;
+
+  /// Return 1 if an error was detected while waiting for the
+  /// event
+  virtual int error_detected (void) const = 0;
+
+  /// Check if we should keep waiting.
+  int keep_waiting (void);
+  //@}
+
+  /// Reset the state, irrespective of the previous states
+  void reset_state (int new_state);
+
+protected:
+
+  /// Validate the state change
+  virtual void state_changed_i (int new_state) = 0;
+
+  /// Check whether we have reached the final state..
+  virtual int is_state_final (void) = 0;
+
+private:
+
+  /// Set the state irrespective of anything.
+  virtual void set_state (int new_state);
+
+protected:
+  /// The current state
+  int state_;
+
+  /// The bounded follower
+  TAO_LF_Follower *follower_;
+};
+
+TAO_END_VERSIONED_NAMESPACE_DECL
+
+#if defined (__ACE_INLINE__)
+# include "tao/LF_Event.inl"
+#endif /* __ACE_INLINE__ */
+
+#include /**/ "ace/post.h"
+
+#endif  /* TAO_LF_EVENT_H */