Fixed problem with INSERT DELAYED

Make killing threads safer

Docs/manual.texi

@@ -7252,7 +7252,7 @@ MySQL. How well a certain platform is suited for a high-load
 mission critical MySQL server is determined by the following
 factors:
 
-@itemize
+@itemize @bullet
 @item
 General stability of the thread library. A platform may have excellent
 reputation otherwise, but if the thread library is unstable in the code
@@ -7384,7 +7384,7 @@ If you want to configure @code{mysqld} with some extra features that are
 NOT in the standard binary distributions.  Here is a list of the most 
 common extra options that you may want to use:
 
-@itemize
+@itemize @bullet
 @item @code{--with-berkeley-db}
 @item @code{--with-innodb}
 @item @code{--with-raid}
@@ -23950,7 +23950,7 @@ to it clean up.
  You should start by creating a wrapper library
 /module with the following functions:
 
-@itemize
+@itemize @bullet
 @item
 @code{safe_writer_connect()}
 @item
@@ -26902,7 +26902,7 @@ flag again, the @code{SQL_MAX_JOIN_SIZE} variable will be ignored.
 You can set a default value for this variable by starting @code{mysqld} with
 @code{-O max_join_size=#}.
 
-@item SQL_SAFE_MODE = 0 | 1
+@item SQL_SAFE_UPDATES = 0 | 1
 If set to @code{1}, MySQL will abort if an @code{UPDATE} or
 @code{DELETE} is attempted that doesn't use a key or @code{LIMIT} in the
 @code{WHERE} clause. This makes it possible to catch wrong updates
@@ -34893,7 +34893,7 @@ effectiveness.  Modifying the default behavior will, in most cases,
 only make the search results worse.  Do not alter the MySQL sources
 unless you know what you are doing!
 
-@itemize
+@itemize @bullet
 
 @item
 Minimal length of word to be indexed is defined in
@@ -42849,7 +42849,7 @@ Unfortunately, we have not yet written full documentation for it - we plan to
 do this shortly.  You can, however, look at our current test cases and use 
 them as an example.  The following points should help you get started:
 
-@itemize
+@itemize @bullet
 @item
 The tests are located in @code{mysql-test/t/*.test}
 
@@ -46712,6 +46712,9 @@ not yet 100% confident in this code.
 @appendixsubsec Changes in release 3.23.42
 @itemize @bullet
 @item
+Fixed problem with @code{INSERT DELAYED} where delay thread could be
+hanging on @code{upgrading locks} without any apparent reasons.
+@item
 Fixed problem with @code{myisampack} and @code{BLOB}.
 @item
 Fixes problem when one edited @code{.MRG} tables by hand.

mysys/thr_lock.c

@@ -115,7 +115,7 @@ my_bool init_thr_lock()
 static uint found_errors=0;
 
 static int check_lock(struct st_lock_list *list, const char* lock_type,
-		      const char *where, my_bool same_thread)
+		      const char *where, my_bool same_thread, bool no_cond)
 {
   THR_LOCK_DATA *data,**prev;
   uint count=0;
@@ -148,6 +148,13 @@ static int check_lock(struct st_lock_list *list, const char* lock_type,
 		lock_type,where);
 	return 1;
       }
+      if (no_cond && data->cond)
+      {
+	fprintf(stderr,
+		"Warning: Found active lock with not reset cond %s: %s\n",
+		lock_type,where);
+	return 1;
+      }
       prev= &data->next;
     }
     if (data)
@@ -172,10 +179,10 @@ static void check_locks(THR_LOCK *lock, const char *where,
   uint old_found_errors=found_errors;
   if (found_errors < MAX_FOUND_ERRORS)
   {
-    if (check_lock(&lock->write,"write",where,1) |
-	check_lock(&lock->write_wait,"write_wait",where,0) |
-	check_lock(&lock->read,"read",where,0) |
-	check_lock(&lock->read_wait,"read_wait",where,0))
+    if (check_lock(&lock->write,"write",where,1,1) |
+	check_lock(&lock->write_wait,"write_wait",where,0,0) |
+	check_lock(&lock->read,"read",where,0,1) |
+	check_lock(&lock->read_wait,"read_wait",where,0,0))
       found_errors++;
 
     if (found_errors < MAX_FOUND_ERRORS)
@@ -326,6 +333,7 @@ void thr_lock_data_init(THR_LOCK *lock,THR_LOCK_DATA *data, void *param)
   data->thread=pthread_self();
   data->thread_id=my_thread_id();		/* for debugging */
   data->status_param=param;
+  data->cond=0;
 }
 
 
@@ -416,6 +424,7 @@ int thr_lock(THR_LOCK_DATA *data,enum thr_lock_type lock_type)
   DBUG_ENTER("thr_lock");
 
   data->next=0;
+  data->cond=0;					/* safety */
   data->type=lock_type;
   data->thread=pthread_self();			/* Must be reset ! */
   data->thread_id=my_thread_id();		/* Must be reset ! */
@@ -977,6 +986,10 @@ my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data)
     lock->write_wait.data=data;
     check_locks(lock,"upgrading lock",0);
   }
+  else
+  {
+    check_locks(lock,"waiting for lock",0);
+  }
   DBUG_RETURN(wait_for_lock(&lock->write_wait,data,1));
 }
 

sql/mysqld.cc

@@ -509,12 +509,14 @@ static void close_connections(void)
     if (tmp->mysys_var)
     {
       tmp->mysys_var->abort=1;
-      if (tmp->mysys_var->current_mutex)
+      pthread_mutex_lock(&tmp->mysys_var->mutex);
+      if (tmp->mysys_var->current_cond)
       {
 	pthread_mutex_lock(tmp->mysys_var->current_mutex);
 	pthread_cond_broadcast(tmp->mysys_var->current_cond);
 	pthread_mutex_unlock(tmp->mysys_var->current_mutex);
       }
+      pthread_mutex_unlock(&tmp->mysys_var->mutex);
     }
   }
   (void) pthread_mutex_unlock(&LOCK_thread_count); // For unlink from list

sql/sql_class.cc

@@ -226,12 +226,12 @@ void THD::prepare_to_die()
       pthread_mutex_lock(&mysys_var->mutex);
       if (!system_thread)		// Don't abort locks
 	mysys_var->abort=1;
-      if (mysys_var->current_mutex)
-	{
-	  pthread_mutex_lock(mysys_var->current_mutex);
-	  pthread_cond_broadcast(mysys_var->current_cond);
-	  pthread_mutex_unlock(mysys_var->current_mutex);
-	}
+      if (mysys_var->current_cond)
+      {
+	pthread_mutex_lock(mysys_var->current_mutex);
+	pthread_cond_broadcast(mysys_var->current_cond);
+	pthread_mutex_unlock(mysys_var->current_mutex);
+      }
       pthread_mutex_unlock(&mysys_var->mutex);
     }
 }

sql/sql_insert.cc

@@ -511,10 +511,12 @@ public:
     delayed_row *row;
     while ((row=rows.get()))
       delete row;
-    pthread_mutex_destroy(&mutex);
     if (table)
       close_thread_tables(&thd);
     VOID(pthread_mutex_lock(&LOCK_thread_count));
+    pthread_mutex_destroy(&mutex);
+    pthread_cond_destroy(&cond);
+    pthread_cond_destroy(&cond_client);
     thd.unlink();				// Must be unlinked under lock
     x_free(thd.query);
     thd.user=thd.host=0;
@@ -842,7 +844,7 @@ void kill_delayed_threads(void)
     if (tmp->thd.mysys_var)
     {
       pthread_mutex_lock(&tmp->thd.mysys_var->mutex);
-      if (tmp->thd.mysys_var->current_mutex)
+      if (tmp->thd.mysys_var->current_cond)
       {
 	if (&tmp->mutex != tmp->thd.mysys_var->current_mutex)
 	  pthread_mutex_lock(tmp->thd.mysys_var->current_mutex);
@@ -970,7 +972,7 @@ static pthread_handler_decl(handle_delayed_insert,arg)
       di->thd.proc_info=0;
 
       DBUG_PRINT("info",("Waiting for someone to insert rows"));
-      for ( ; ;)
+      while (!thd->killed)
       {
 	int error;
 #if (defined(HAVE_BROKEN_COND_TIMEDWAIT) || defined(HAVE_LINUXTHREADS))