Commit 779f9fed authored by unknown's avatar unknown
Browse files

Fix of debbuging mode of query cache (proposed by Monty reviewed by me). 


sql/sql_cache.cc:
  Call of BLOCK_UNLOCK_WR() moved before query_cache.check_integrity() call which privent lock of query cache during debugging.
  Comments added.
parent a4823607

sql/sql_cache.cc

+24 −18
Original line number Diff line number Diff line
@@ -702,6 +702,7 @@ void query_cache_abort(NET *net) 


void query_cache_end_of_result(THD *thd)

{

  Query_cache_block *query_block;

  DBUG_ENTER("query_cache_end_of_result");



  /* See the comment on double-check locking usage above. */
@@ -717,13 +718,9 @@ void query_cache_end_of_result(THD *thd) 


  if (unlikely(query_cache.query_cache_size == 0 ||

               query_cache.flush_in_progress))

  {

    STRUCT_UNLOCK(&query_cache.structure_guard_mutex);

    DBUG_VOID_RETURN;

  }

    goto end;



  Query_cache_block *query_block= ((Query_cache_block*)

                                   thd->net.query_cache_query);

  query_block= ((Query_cache_block*) thd->net.query_cache_query);

  if (query_block)

  {

    DUMP(&query_cache);
@@ -742,27 +739,25 @@ void query_cache_end_of_result(THD *thd) 
                           header->query()));

      query_cache.wreck(__LINE__, "");



      STRUCT_UNLOCK(&query_cache.structure_guard_mutex);



      DBUG_VOID_RETURN;

      /*

        We do not need call of BLOCK_UNLOCK_WR(query_block); here because

        query_cache.wreck() switched query cache off but left content

        untouched for investigation (it is debugging method).

      */

      goto end;

    }

#endif

    header->found_rows(current_thd->limit_found_rows);

    header->result()->type= Query_cache_block::RESULT;

    header->writer(0);

    thd->net.query_cache_query= 0;

    BLOCK_UNLOCK_WR(query_block);

    DBUG_EXECUTE("check_querycache",query_cache.check_integrity(1););



    STRUCT_UNLOCK(&query_cache.structure_guard_mutex);



    BLOCK_UNLOCK_WR(query_block);

  }

  else

  {

    // Cache was flushed or resized and query was deleted => do nothing

    STRUCT_UNLOCK(&query_cache.structure_guard_mutex);

  }



end:

  STRUCT_UNLOCK(&query_cache.structure_guard_mutex);

  DBUG_VOID_RETURN;

}
@@ -3529,7 +3524,7 @@ uint Query_cache::filename_2_table_key (char *key, const char *path, 


#if defined(DBUG_OFF) && !defined(USE_QUERY_CACHE_INTEGRITY_CHECK)



void wreck(uint line, const char *message) {}

void wreck(uint line, const char *message) { query_cache_size = 0; }

void bins_dump() {}

void cache_dump() {}

void queries_dump() {}
@@ -3541,6 +3536,17 @@ my_bool in_blocks(Query_cache_block * point) { return 0; } 


#else





/*

  Debug method which switch query cache off but left content for

  investigation.



  SYNOPSIS

    Query_cache::wreck()

    line                 line of the wreck() call

    message              message for logging

*/



void Query_cache::wreck(uint line, const char *message)

{

  THD *thd=current_thd;