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Diffstat (limited to 'TAO/tao/Leader_Follower.h')
| -rw-r--r-- | TAO/tao/Leader_Follower.h | 299 |
1 files changed, 0 insertions, 299 deletions
diff --git a/TAO/tao/Leader_Follower.h b/TAO/tao/Leader_Follower.h deleted file mode 100644 index 46fa3c312a7..00000000000 --- a/TAO/tao/Leader_Follower.h +++ /dev/null @@ -1,299 +0,0 @@ -// -*- C++ -*- - -//============================================================================= -/** - * @file Leader_Follower.h - * - * $Id$ - * - * @author Carlos O'Ryan (coryan@cs.wustl.edu) - */ -//============================================================================= - - -#ifndef TAO_LEADER_FOLLOWER_H -#define TAO_LEADER_FOLLOWER_H - -#include /**/ "ace/pre.h" -#include "ace/os_include/os_errno.h" - -#if !defined (ACE_LACKS_PRAGMA_ONCE) -# pragma once -#endif /* ACE_LACKS_PRAGMA_ONCE */ - -#include "tao/New_Leader_Generator.h" -#include "tao/LF_Follower.h" -#include "ace/Reverse_Lock_T.h" -#include "ace/Intrusive_List.h" -#include "ace/Intrusive_List_Node.h" -#include "ace/OS_NS_Thread.h" - -ACE_BEGIN_VERSIONED_NAMESPACE_DECL -class ACE_Reactor; -ACE_END_VERSIONED_NAMESPACE_DECL - -TAO_BEGIN_VERSIONED_NAMESPACE_DECL - -class TAO_LF_Event; -class TAO_Transport; -class TAO_ORB_Core; -class TAO_ORB_Core_TSS_Resources; - -/** - * @class TAO_Leader_Follower - * - * @brief TAO_Leader_Follower - * - * TAO_Leader_Follower - */ -class TAO_Export TAO_Leader_Follower -{ -public: - /// Constructor - TAO_Leader_Follower (TAO_ORB_Core *orb_core, - TAO_New_Leader_Generator *new_leader_generator = 0); - - /// Destructor - ~TAO_Leader_Follower (void); - - /// The current thread has become a server thread (i.e. called - /// ORB::run), update any flags and counters. - int set_event_loop_thread (ACE_Time_Value *max_wait_time); - - /// The current thread is not a server thread anymore, reset any - /// flags and counters. - void reset_event_loop_thread (void); - - /// This thread is going to perform an upcall, it will no longer be - /// an event loop thread. - void set_upcall_thread (void); - - /// Is there any thread running as a leader? - int leader_available (void) const; - - /// A server thread is making a request. - void set_client_thread (void); - - /// A server thread has finished is making a request. - void reset_client_thread (void); - - /// Wait on the Leader/Followers loop until one event happens. - /** - * @param event The event we wait for, the loop iterates until the - * event is sucessful, or it fails due to timeout, and error or a - * connection closed. - * @param transport The transport attached to the event - * @param max_wait_time Limit the time spent on the loop - * @param return Returns -1 on error, 0 or non-zero value - * otherwise. - * - * @todo Document this better, split the Follower code to the - * TAO_LF_Follower class, we probably don't need the transport - * object. - */ - int wait_for_event (TAO_LF_Event *event, - TAO_Transport *transport, - ACE_Time_Value *max_wait_time); - - /// The current thread has become the leader thread in the - /// client side leader-follower set. - void set_client_leader_thread (void) ; - - /// The current thread is no longer the leader thread in the client - /// side leader-follower set. - void reset_client_leader_thread (void) ; - - /// sets the thread ID of the leader thread in the leader-follower - /// model - void set_client_leader_thread (ACE_thread_t thread_ID); - - /// checks if we are a leader thread - int is_client_leader_thread (void) const; - - /** - * A leader thread is relinquishing its role, unless there are more - * leader threads running pick up a follower (if there is any) to - * play the leader role. - */ - int elect_new_leader (void); - - /** @name Follower creation/destructions - * - * The Leader/Followers set acts as a factory for the Follower - * objects. Followers are used to represent a thread blocked - * waiting in the Follower set. - * - * The Leader/Followers abstraction keeps a list of the waiting - * followers, so it can wake up one when the leader thread stops - * handling events. - * - * For performance reasons the Leader/Followers set uses a pool (or - * free-list) to keep Follower objects unattached to any thread. It - * could be tempting to use TSS to keep such followers, after all a - * thread can only need one such Follower object, however, that does - * not work with multiple Leader/Followers sets, consult this bug - * report for more details: - * - * http://ace.cs.wustl.edu/bugzilla/show_bug.cgi?id=296 - * - */ - //@{ - /// Allocate a new follower to the caller. - TAO_LF_Follower *allocate_follower (void); - - /// The caller has finished using a follower. - void release_follower (TAO_LF_Follower *); - //@} - - /** @name Follower Set Operations - * - */ - //@{ - /// Add a new follower to the set - void add_follower (TAO_LF_Follower *follower); - - /// Removes a follower from the leader-follower set - void remove_follower (TAO_LF_Follower *follower); - - /// Checks if there are any followers available - /** - * @return 1 if there follower set is not empty - */ - int follower_available (void) const; - - //@} - - /// Get a reference to the underlying mutex - TAO_SYNCH_MUTEX &lock (void); - - /// Provide a pre-initialized reverse lock for the Leader/Followers - /// set. - /** - * The Leader/Followers set mutex must be release during some long - * running operations. This helper class simplifies the process of - * releasing and reacquiring said mutex. - */ - ACE_Reverse_Lock<TAO_SYNCH_MUTEX> &reverse_lock (void); - - /// Check if there are any client threads running - int has_clients (void) const; - - /// Accesor to the reactor - ACE_Reactor *reactor (void); - - /// Called when we are out of leaders. - void no_leaders_available (void); - -private: - /// Shortcut to obtain the TSS resources of the orb core. - TAO_ORB_Core_TSS_Resources *get_tss_resources (void) const; - - /// Wait for the client leader to complete. - int wait_for_client_leader_to_complete (ACE_Time_Value *max_wait_time); - - /** - * Implement the reset_event_loop_thread() method, once the TSS - * resources have been acquired. - * Also used in the set_upcall_thread. - */ - void reset_event_loop_thread_i (TAO_ORB_Core_TSS_Resources *tss); - - /** @name Follower Set Operations - * - */ - //@{ - /// Remote a follower from the Followers set and promote it to the - /// leader role. - /** - * This is a helper routine for elect_new_leader(), after verifying - * that all the pre-conditions are satisfied the Follower set is - * changed and the promoted Follower is signaled. - */ - int elect_new_leader_i (void); - - //@} - -private: - /// The orb core - TAO_ORB_Core *orb_core_; - - /// To synchronize access to the members. - TAO_SYNCH_MUTEX lock_; - - /// do protect the access to the following three members - ACE_Reverse_Lock<TAO_SYNCH_MUTEX> reverse_lock_; - - /// Implement the Leader/Followers set using an intrusive list - typedef ACE_Intrusive_List<TAO_LF_Follower> Follower_Set; - Follower_Set follower_set_; - - /// Use a free list to allocate and release Follower objects - Follower_Set follower_free_list_; - - /** - * Count the number of active leaders. - * There could be many leaders in the thread pool (i.e. calling - * ORB::run), and the same leader could show up multiple times as it - * receives nested upcalls and sends more requests. - */ - int leaders_; - - /// Count the number of active clients, this is useful to know when - /// to deactivate the reactor - int clients_; - - /// The reactor - ACE_Reactor *reactor_; - - /// Is a client thread the current leader? - int client_thread_is_leader_; - - /// Are server threads waiting for the client leader to complete? - int event_loop_threads_waiting_; - - /// Condition variable for server threads waiting for the client - /// leader to complete. - TAO_SYNCH_CONDITION event_loop_threads_condition_; - - /// Leader/Follower class uses this method to notify the system that - /// we are out of leaders. - TAO_New_Leader_Generator *new_leader_generator_; -}; - -class TAO_Export TAO_LF_Client_Thread_Helper -{ -public: - /// Constructor - TAO_LF_Client_Thread_Helper (TAO_Leader_Follower &leader_follower); - - /// Destructor - ~TAO_LF_Client_Thread_Helper (void); - -private: - /// Reference to leader/followers object. - TAO_Leader_Follower &leader_follower_; -}; - -class TAO_Export TAO_LF_Client_Leader_Thread_Helper -{ -public: - /// Constructor - TAO_LF_Client_Leader_Thread_Helper (TAO_Leader_Follower &leader_follower); - - /// Destructor - ~TAO_LF_Client_Leader_Thread_Helper (void); - -private: - /// Reference to leader/followers object. - TAO_Leader_Follower &leader_follower_; -}; - -TAO_END_VERSIONED_NAMESPACE_DECL - -#if defined (__ACE_INLINE__) -# include "tao/Leader_Follower.i" -#endif /* __ACE_INLINE__ */ - -#include /**/ "ace/post.h" - -#endif /* TAO_LEADER_FOLLOWER_H */ |