automerge

include/hash.h

@@ -21,6 +21,40 @@
 extern "C" {
 #endif
 
+/*
+  There was a problem on MacOSX with a shared object ha_example.so.
+  It used hash_search(). During build of ha_example.so no libmysys
+  was specified. Since MacOSX had a hash_search() in the system
+  library, it built the shared object so that the dynamic linker
+  linked hash_search() to the system library, which caused a crash
+  when called. To come around this, we renamed hash_search() to
+  my_hash_search(), as we did long ago with hash_insert() and
+  hash_reset(). However, this time we made the move complete with
+  all names. To keep compatibility, we redefine the old names.
+  Since every C and C++ file, that uses HASH, needs to include
+  this file, the change is complete. Both names could be used
+  in the code, but the my_* versions are recommended now.
+*/
+#define hash_get_key    my_hash_get_key
+#define hash_free_key   my_hash_free_key
+#define hash_init       my_hash_init
+#define hash_init2      my_hash_init2
+#define _hash_init      _my_hash_init
+#define hash_free       my_hash_free
+#define hash_reset      my_hash_reset
+#define hash_element    my_hash_element
+#define hash_search     my_hash_search
+#define hash_first      my_hash_first
+#define hash_next       my_hash_next
+#define hash_insert     my_hash_insert
+#define hash_delete     my_hash_delete
+#define hash_update     my_hash_update
+#define hash_replace    my_hash_replace
+#define hash_check      my_hash_check
+#define hash_clear      my_hash_clear
+#define hash_inited     my_hash_inited
+#define hash_init_opt   my_hash_init_opt
+
 /*
   Overhead to store an element in hash
   Can be used to approximate memory consumption for a hash
@@ -30,8 +64,8 @@ extern "C" {
 /* flags for hash_init */
 #define HASH_UNIQUE     1       /* hash_insert fails on duplicate key */
 
-typedef uchar *(*hash_get_key)(const uchar *,size_t*,my_bool);
-typedef void (*hash_free_key)(void *);
+typedef uchar *(*my_hash_get_key)(const uchar *,size_t*,my_bool);
+typedef void (*my_hash_free_key)(void *);
 
 typedef struct st_hash {
   size_t key_offset,key_length;		/* Length of key if const length */
@@ -39,7 +73,7 @@ typedef struct st_hash {
   ulong records;
   uint flags;
   DYNAMIC_ARRAY array;				/* Place for hash_keys */
-  hash_get_key get_key;
+  my_hash_get_key get_key;
   void (*free)(void *);
   CHARSET_INFO *charset;
 } HASH;
@@ -47,30 +81,34 @@ typedef struct st_hash {
 /* A search iterator state */
 typedef uint HASH_SEARCH_STATE;
 
-#define hash_init(A,B,C,D,E,F,G,H) _hash_init(A,0,B,C,D,E,F,G,H CALLER_INFO)
-#define hash_init2(A,B,C,D,E,F,G,H,I) _hash_init(A,B,C,D,E,F,G,H,I CALLER_INFO)
-my_bool _hash_init(HASH *hash, uint growth_size,CHARSET_INFO *charset,
-		   ulong default_array_elements, size_t key_offset,
-		   size_t key_length, hash_get_key get_key,
-		   void (*free_element)(void*), uint flags CALLER_INFO_PROTO);
-void hash_free(HASH *tree);
+#define my_hash_init(A,B,C,D,E,F,G,H) \
+          _my_hash_init(A,0,B,C,D,E,F,G,H CALLER_INFO)
+#define my_hash_init2(A,B,C,D,E,F,G,H,I) \
+          _my_hash_init(A,B,C,D,E,F,G,H,I CALLER_INFO)
+my_bool _my_hash_init(HASH *hash, uint growth_size, CHARSET_INFO *charset,
+                      ulong default_array_elements, size_t key_offset,
+                      size_t key_length, my_hash_get_key get_key,
+                      void (*free_element)(void*),
+                      uint flags CALLER_INFO_PROTO);
+void my_hash_free(HASH *tree);
 void my_hash_reset(HASH *hash);
-uchar *hash_element(HASH *hash,ulong idx);
-uchar *hash_search(const HASH *info, const uchar *key, size_t length);
-uchar *hash_first(const HASH *info, const uchar *key, size_t length,
-                HASH_SEARCH_STATE *state);
-uchar *hash_next(const HASH *info, const uchar *key, size_t length,
-                 HASH_SEARCH_STATE *state);
-my_bool my_hash_insert(HASH *info,const uchar *data);
-my_bool hash_delete(HASH *hash,uchar *record);
-my_bool hash_update(HASH *hash,uchar *record,uchar *old_key,size_t old_key_length);
-void hash_replace(HASH *hash, HASH_SEARCH_STATE *state, uchar *new_row);
-my_bool hash_check(HASH *hash);			/* Only in debug library */
+uchar *my_hash_element(HASH *hash, ulong idx);
+uchar *my_hash_search(const HASH *info, const uchar *key, size_t length);
+uchar *my_hash_first(const HASH *info, const uchar *key, size_t length,
+                     HASH_SEARCH_STATE *state);
+uchar *my_hash_next(const HASH *info, const uchar *key, size_t length,
+                    HASH_SEARCH_STATE *state);
+my_bool my_hash_insert(HASH *info, const uchar *data);
+my_bool my_hash_delete(HASH *hash, uchar *record);
+my_bool my_hash_update(HASH *hash, uchar *record, uchar *old_key,
+                       size_t old_key_length);
+void my_hash_replace(HASH *hash, HASH_SEARCH_STATE *state, uchar *new_row);
+my_bool my_hash_check(HASH *hash); /* Only in debug library */
 
-#define hash_clear(H) bzero((char*) (H),sizeof(*(H)))
-#define hash_inited(H) ((H)->array.buffer != 0)
-#define hash_init_opt(A,B,C,D,E,F,G,H) \
-          (!hash_inited(A) && _hash_init(A,0,B,C,D,E,F,G, H CALLER_INFO))
+#define my_hash_clear(H) bzero((char*) (H), sizeof(*(H)))
+#define my_hash_inited(H) ((H)->array.buffer != 0)
+#define my_hash_init_opt(A,B,C,D,E,F,G,H) \
+          (!my_hash_inited(A) && _my_hash_init(A,0,B,C,D,E,F,G, H CALLER_INFO))
 
 #ifdef	__cplusplus
 }

sql/handler.cc

@@ -373,6 +373,10 @@ int ha_finalize_handlerton(st_plugin_int *plugin)
   handlerton *hton= (handlerton *)plugin->data;
   DBUG_ENTER("ha_finalize_handlerton");
 
+  /* hton can be NULL here, if ha_initialize_handlerton() failed. */
+  if (!hton)
+    goto end;
+
   switch (hton->state)
   {
   case SHOW_OPTION_NO:
@@ -401,8 +405,16 @@ int ha_finalize_handlerton(st_plugin_int *plugin)
     }
   }
 
+  /*
+    In case a plugin is uninstalled and re-installed later, it should
+    reuse an array slot. Otherwise the number of uninstall/install
+    cycles would be limited.
+  */
+  hton2plugin[hton->slot]= NULL;
+
   my_free((uchar*)hton, MYF(0));
 
+ end:
   DBUG_RETURN(0);
 }
 
@@ -437,6 +449,7 @@ int ha_initialize_handlerton(st_plugin_int *plugin)
   case SHOW_OPTION_YES:
     {
       uint tmp;
+      ulong fslot;
       /* now check the db_type for conflict */
       if (hton->db_type <= DB_TYPE_UNKNOWN ||
           hton->db_type >= DB_TYPE_DEFAULT ||
@@ -461,7 +474,31 @@ int ha_initialize_handlerton(st_plugin_int *plugin)
       tmp= hton->savepoint_offset;
       hton->savepoint_offset= savepoint_alloc_size;
       savepoint_alloc_size+= tmp;
-      hton->slot= total_ha++;
+
+      /*
+        In case a plugin is uninstalled and re-installed later, it should
+        reuse an array slot. Otherwise the number of uninstall/install
+        cycles would be limited. So look for a free slot.
+      */
+      DBUG_PRINT("plugin", ("total_ha: %lu", total_ha));
+      for (fslot= 0; fslot < total_ha; fslot++)
+      {
+        if (!hton2plugin[fslot])
+          break;
+      }
+      if (fslot < total_ha)
+        hton->slot= fslot;
+      else
+      {
+        if (total_ha >= MAX_HA)
+        {
+          sql_print_error("Too many plugins loaded. Limit is %lu. "
+                          "Failed on '%s'", (ulong) MAX_HA, plugin->name.str);
+          goto err;
+        }
+        hton->slot= total_ha++;
+      }
+
       hton2plugin[hton->slot]=plugin;
       if (hton->prepare)
         total_ha_2pc++;