1 files changed, 51 insertions, 74 deletions

diff --git a/server-tools/instance-manager/guardian.h b/server-tools/instance-manager/guardian.h
index 42d4f5e2ba4..d78058a6fc5 100644
--- a/server-tools/instance-manager/guardian.h
+++ b/server-tools/instance-manager/guardian.h
@@ -16,10 +16,12 @@
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
 
-#include "thread_registry.h"
+#include <my_global.h>
 #include <my_sys.h>
 #include <my_list.h>
 
+#include "thread_registry.h"
+
 #if defined(__GNUC__) && defined(USE_PRAGMA_INTERFACE)
 #pragma interface
 #endif
@@ -27,7 +29,6 @@
 class Instance;
 class Instance_map;
 class Thread_registry;
-struct GUARD_NODE;
 
 /**
   The guardian thread is responsible for monitoring and restarting of guarded
@@ -37,97 +38,73 @@ struct GUARD_NODE;
 class Guardian: public Thread
 {
 public:
-  /* states of an instance */
-  enum enum_instance_state { NOT_STARTED= 1, STARTING, STARTED, JUST_CRASHED,
-                             CRASHED, CRASHED_AND_ABANDONED, STOPPING };
-
-  /*
-    The Guardian list node structure. Guardian utilizes it to store
-    guarded instances plus some additional info.
-  */
+  Guardian(Thread_registry *thread_registry_arg,
+           Instance_map *instance_map_arg);
+  ~Guardian();
 
-  struct GUARD_NODE
-  {
-    Instance *instance;
-    /* state of an instance (i.e. STARTED, CRASHED, etc.) */
-    enum_instance_state state;
-    /* the amount of attemts to restart instance (cleaned up at success) */
-    int restart_counter;
-    /* triggered at a crash */
-    time_t crash_moment;
-    /* General time field. Used to provide timeouts (at shutdown and restart) */
-    time_t last_checked;
-  };
-
-  /* Return client state name. */
-  static const char *get_instance_state_name(enum_instance_state state);
+  void init();
 
-  Guardian(Thread_registry *thread_registry_arg,
-           Instance_map *instance_map_arg,
-           uint monitoring_interval_arg);
-  virtual ~Guardian();
-  /* Initialize or refresh the list of guarded instances */
-  int init();
-  /* Request guardian shutdown. Stop instances if needed */
+public:
   void request_shutdown();
-  /* Start instance protection */
-  int guard(Instance *instance, bool nolock= FALSE);
-  /* Stop instance protection */
-  int stop_guard(Instance *instance);
-  /* Returns TRUE if guardian thread is stopped */
-  int is_stopped();
+
+  bool is_stopped();
+
   void lock();
   void unlock();
 
-  /*
-    Return an internal list node for the given instance if the instance is
-    managed by Guardian. Otherwise, return NULL.
+  void ping();
 
-    MT-NOTE: must be called under acquired lock.
-  */
-  LIST *find_instance_node(Instance *instance);
+protected:
+  virtual void run();
+
+private:
+  void stop_instances();
 
-  /* The operation is used to check if the instance is active or not. */
-  bool is_active(Instance *instance);
+  void process_instance(Instance *instance);
 
+private:
   /*
-    Return state of the given instance list node. The pointer must specify
-    a valid list node.
+    LOCK_guardian protectes the members in this section:
+      - shutdown_requested;
+      - stopped;
+
+    Also, it is used for COND_guardian.
   */
-  inline enum_instance_state get_instance_state(LIST *instance_node);
-protected:
-  /* Main funtion of the thread */
-  virtual void run();
+  pthread_mutex_t LOCK_guardian;
 
-public:
+  /*
+    Guardian's main loop waits on this condition. So, it should be signalled
+    each time, when instance state has been changed and we want Guardian to
+    wake up.
+
+    TODO: Change this to having data-scoped conditions, i.e. conditions,
+    which indicate that some data has been changed.
+  */
   pthread_cond_t COND_guardian;
 
-private:
-  /* Prepares Guardian shutdown. Stops instances is needed */
-  int stop_instances();
-  /* check instance state and act accordingly */
-  void process_instance(Instance *instance, GUARD_NODE *current_node,
-                        LIST **guarded_instances, LIST *elem);
+  /*
+    This variable is set to TRUE, when Manager thread is shutting down.
+    The flag is used by Guardian thread to understand that it's time to
+    finish.
+  */
+  bool shutdown_requested;
+
+  /*
+    This flag is set to TRUE on shutdown by Guardian thread, when all guarded
+    mysqlds are stopped.
 
-  int stopped;
+    The flag is used in the Manager thread to wait for Guardian to stop all
+    mysqlds.
+  */
+  bool stopped;
 
-private:
-  pthread_mutex_t LOCK_guardian;
   Thread_info thread_info;
-  int monitoring_interval;
   Thread_registry *thread_registry;
   Instance_map *instance_map;
-  LIST *guarded_instances;
-  MEM_ROOT alloc;
-  /* this variable is set to TRUE when we want to stop Guardian thread */
-  bool shutdown_requested;
-};
-
 
-inline Guardian::enum_instance_state
-Guardian::get_instance_state(LIST *instance_node)
-{
-  return ((GUARD_NODE *) instance_node->data)->state;
-}
+private:
+  Guardian(const Guardian &);
+  Guardian&operator =(const Guardian &);
+};
 
 #endif /* INCLUDES_MYSQL_INSTANCE_MANAGER_GUARDIAN_H */