Merge moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.0

into  moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.0-bug21051-2

include/mysql_com.h

@@ -209,7 +209,13 @@ typedef struct st_net {
   char last_error[MYSQL_ERRMSG_SIZE], sqlstate[SQLSTATE_LENGTH+1];
   unsigned int last_errno;
   unsigned char error;
+
+  /*
+    'query_cache_query' should be accessed only via query cache
+    functions and methods to maintain proper locking.
+  */
   gptr query_cache_query;
+
   my_bool report_error; /* We should report error (we have unreported error) */
   my_bool return_errno;
 } NET;

sql/net_serv.cc

@@ -96,8 +96,11 @@ extern uint test_flags;
 extern ulong bytes_sent, bytes_received, net_big_packet_count;
 extern pthread_mutex_t LOCK_bytes_sent , LOCK_bytes_received;
 #ifndef MYSQL_INSTANCE_MANAGER
-extern void query_cache_insert(NET *net, const char *packet, ulong length);
+#ifdef HAVE_QUERY_CACHE
 #define USE_QUERY_CACHE
+extern void query_cache_init_query(NET *net);
+extern void query_cache_insert(NET *net, const char *packet, ulong length);
+#endif // HAVE_QUERY_CACHE
 #define update_statistics(A) A
 #endif /* MYSQL_INSTANCE_MANGER */
 #endif /* defined(MYSQL_SERVER) && !defined(MYSQL_INSTANCE_MANAGER) */
@@ -133,7 +136,11 @@ my_bool my_net_init(NET *net, Vio* vio)
   net->compress=0; net->reading_or_writing=0;
   net->where_b = net->remain_in_buf=0;
   net->last_errno=0;
-  net->query_cache_query=0;
+#ifdef USE_QUERY_CACHE
+  query_cache_init_query(net);
+#else
+  net->query_cache_query= 0;
+#endif
   net->report_error= 0;
 
   if (vio != 0)					/* If real connection */
@@ -552,10 +559,8 @@ net_real_write(NET *net,const char *packet,ulong len)
   my_bool net_blocking = vio_is_blocking(net->vio);
   DBUG_ENTER("net_real_write");
 
-#if defined(MYSQL_SERVER) && defined(HAVE_QUERY_CACHE) \
-                          && !defined(MYSQL_INSTANCE_MANAGER)
-  if (net->query_cache_query != 0)
-    query_cache_insert(net, packet, len);
+#if defined(MYSQL_SERVER) && defined(USE_QUERY_CACHE)
+  query_cache_insert(net, packet, len);
 #endif
 
   if (net->error == 2)

sql/sql_cache.h

@@ -195,7 +195,6 @@ extern "C"
   byte *query_cache_table_get_key(const byte *record, uint *length,
 				  my_bool not_used);
 }
-void query_cache_insert(NET *thd, const char *packet, ulong length);
 extern "C" void query_cache_invalidate_by_MyISAM_filename(const char* filename);
 
 
@@ -241,6 +240,12 @@ class Query_cache
   ulong free_memory, queries_in_cache, hits, inserts, refused,
     free_memory_blocks, total_blocks, lowmem_prunes;
 
+private:
+  pthread_cond_t COND_flush_finished;
+  bool flush_in_progress;
+
+  void free_query_internal(Query_cache_block *point);
+
 protected:
   /*
     The following mutex is locked when searching or changing global
@@ -249,6 +254,12 @@ class Query_cache
     LOCK SEQUENCE (to prevent deadlocks):
       1. structure_guard_mutex
       2. query block (for operation inside query (query block/results))
+
+    Thread doing cache flush releases the mutex once it sets
+    flush_in_progress flag, so other threads may bypass the cache as
+    if it is disabled, not waiting for reset to finish.  The exception
+    is other threads that were going to do cache flush---they'll wait
+    till the end of a flush operation.
   */
   pthread_mutex_t structure_guard_mutex;
   byte *cache;					// cache memory
@@ -358,6 +369,7 @@ class Query_cache
     If query is cacheable return number tables in query
     (query without tables not cached)
   */
+  static
   TABLE_COUNTER_TYPE is_cacheable(THD *thd, uint32 query_len, char *query,
 				  LEX *lex, TABLE_LIST *tables_used,
 				  uint8 *tables_type);
@@ -410,6 +422,7 @@ class Query_cache
 
   void destroy();
 
+  friend void query_cache_init_query(NET *net);
   friend void query_cache_insert(NET *net, const char *packet, ulong length);
   friend void query_cache_end_of_result(THD *thd);
   friend void query_cache_abort(NET *net);
@@ -435,6 +448,8 @@ class Query_cache
 
 extern Query_cache query_cache;
 extern TYPELIB query_cache_type_typelib;
+void query_cache_init_query(NET *net);
+void query_cache_insert(NET *net, const char *packet, ulong length);
 void query_cache_end_of_result(THD *thd);
 void query_cache_abort(NET *net);
 

sql/sql_class.cc

@@ -224,7 +224,7 @@ THD::THD()
 #endif
   client_capabilities= 0;                       // minimalistic client
   net.last_error[0]=0;                          // If error on boot
-  net.query_cache_query=0;                      // If error on boot
+  query_cache_init_query(&net);                 // If error on boot
   ull=0;
   system_thread= cleanup_done= abort_on_warning= no_warnings_for_error= 0;
   peer_port= 0;					// For SHOW PROCESSLIST