From fa98e9c71808b704dedc360c7412a647c8444097 Mon Sep 17 00:00:00 2001
From: "serg@janus.mylan" <>
Date: Wed, 6 Sep 2006 10:22:59 +0200
Subject: [PATCH] converting plugin states to bitmask to simplify testing.
 state_mask argument to plugin_foreach()

---
 sql/sql_plugin.cc | 16 +++++++++-------
 sql/sql_plugin.h  | 25 +++++++++++++++----------
 sql/sql_show.cc   |  5 +++--
 3 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index 8ed16d8af58..b66d2d20925 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -372,7 +372,7 @@ struct st_plugin_int *plugin_lock(const LEX_STRING *name, int type)
   rw_wrlock(&THR_LOCK_plugin);
   if ((rc= plugin_find_internal(name, type)))
   {
-    if (rc->state == PLUGIN_IS_READY || rc->state == PLUGIN_IS_UNINITIALIZED)
+    if (rc->state & (PLUGIN_IS_READY | PLUGIN_IS_UNINITIALIZED))
       rc->ref_count++;
     else
       rc= 0;
@@ -943,13 +943,15 @@ err:
   DBUG_RETURN(TRUE);
 }
 
-my_bool plugin_foreach(THD *thd, plugin_foreach_func *func,
-                       int type, void *arg)
+my_bool plugin_foreach_with_mask(THD *thd, plugin_foreach_func *func,
+                       int type, uint state_mask, void *arg)
 {
   uint idx, total;
   struct st_plugin_int *plugin, **plugins;
   int version=plugin_array_version;
-  DBUG_ENTER("plugin_foreach");
+  DBUG_ENTER("plugin_foreach_with_mask");
+
+  state_mask= ~state_mask; // do it only once
 
   rw_rdlock(&THR_LOCK_plugin);
   if (type == MYSQL_ANY_PLUGIN)
@@ -959,7 +961,7 @@ my_bool plugin_foreach(THD *thd, plugin_foreach_func *func,
     for (idx= 0; idx < total; idx++)
     {
       plugin= dynamic_element(&plugin_array, idx, struct st_plugin_int *);
-      if (plugin->state == PLUGIN_IS_FREED)
+      if (plugin->state & state_mask)
         continue;
       plugins[idx]= plugin;
     }
@@ -972,7 +974,7 @@ my_bool plugin_foreach(THD *thd, plugin_foreach_func *func,
     for (idx= 0; idx < total; idx++)
     {
       plugin= (struct st_plugin_int *) hash_element(hash, idx);
-      if (plugin->state == PLUGIN_IS_FREED)
+      if (plugin->state & state_mask)
         continue;
       plugins[idx]= plugin;
     }
@@ -986,7 +988,7 @@ my_bool plugin_foreach(THD *thd, plugin_foreach_func *func,
     {
       rw_rdlock(&THR_LOCK_plugin);
       for (uint i=idx; i < total; i++)
-        if (plugins[i]->state == PLUGIN_IS_FREED)
+        if (plugins[i]->state & state_mask)
           plugins[i]=0;
       rw_unlock(&THR_LOCK_plugin);
     }
diff --git a/sql/sql_plugin.h b/sql/sql_plugin.h
index ed7ba36ac84..fa3440f7f68 100644
--- a/sql/sql_plugin.h
+++ b/sql/sql_plugin.h
@@ -31,13 +31,17 @@ typedef struct st_mysql_show_var SHOW_VAR;
 
 #define MYSQL_ANY_PLUGIN         -1
 
-enum enum_plugin_state
-{
-  PLUGIN_IS_FREED= 0,
-  PLUGIN_IS_DELETED,
-  PLUGIN_IS_UNINITIALIZED,
-  PLUGIN_IS_READY
-};
+/*
+  different values of st_plugin_int::state
+  though they look like a bitmap, plugin may only
+  be in one of those eigenstates, not in a superposition of them :)
+  It's a bitmap, because it makes it easier to test
+  "whether the state is one of those..."
+*/
+#define PLUGIN_IS_FREED         1
+#define PLUGIN_IS_DELETED       2
+#define PLUGIN_IS_UNINITIALIZED 4
+#define PLUGIN_IS_READY         8
 
 /* A handle for the dynamic library containing a plugin or plugins. */
 
@@ -57,7 +61,7 @@ struct st_plugin_int
   LEX_STRING name;
   struct st_mysql_plugin *plugin;
   struct st_plugin_dl *plugin_dl;
-  enum enum_plugin_state state;
+  uint state;
   uint ref_count;               /* number of threads using the plugin */
   void *data;                   /* plugin type specific, e.g. handlerton */
 };
@@ -78,6 +82,7 @@ extern my_bool mysql_uninstall_plugin(THD *thd, const LEX_STRING *name);
 typedef my_bool (plugin_foreach_func)(THD *thd,
                                       st_plugin_int *plugin,
                                       void *arg);
-extern my_bool plugin_foreach(THD *thd, plugin_foreach_func *func,
-                              int type, void *arg);
+#define plugin_foreach(A,B,C,D) plugin_foreach_with_mask(A,B,C,PLUGIN_IS_READY,D)
+extern my_bool plugin_foreach_with_mask(THD *thd, plugin_foreach_func *func,
+                                        int type, uint state_mask, void *arg);
 #endif
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index a8bf2695ac4..3acc025b84f 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -220,9 +220,10 @@ int fill_plugins(THD *thd, TABLE_LIST *tables, COND *cond)
   DBUG_ENTER("fill_plugins");
   TABLE *table= tables->table;
 
-  if (plugin_foreach(thd, show_plugins, MYSQL_ANY_PLUGIN, table))
+  if (plugin_foreach_with_mask(thd, show_plugins, MYSQL_ANY_PLUGIN,
+                               ~PLUGIN_IS_FREED, table))
     DBUG_RETURN(1);
-    
+
   DBUG_RETURN(0);
 }