MDEV-4065 thd_kill_statement service

include/mysql/service_kill_statement.h

@@ -0,0 +1,71 @@
+/* Copyright (c) 2013, Monty Program Ab.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+#ifndef MYSQL_SERVICE_KILL_STATEMENT_INCLUDED
+#define MYSQL_SERVICE_KILL_STATEMENT_INCLUDED
+
+/**
+  @file
+  This service provides functions that allow plugins to support
+  the KILL statement.
+
+  In MySQL support for the KILL statement is cooperative. The KILL
+  statement only sets a "killed" flag. This function returns the value
+  of that flag.  A thread should check it often, especially inside
+  time-consuming loops, and gracefully abort the operation if it is
+  non-zero.
+
+  thd_is_killed(thd)
+  @return 0 - no KILL statement was issued, continue normally
+  @return 1 - there was a KILL statement, abort the execution.
+
+  thd_kill_level(thd)
+  @return thd_kill_levels_enum values
+*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum thd_kill_levels {
+  THD_IS_NOT_KILLED=0,
+  THD_ABORT_SOFTLY=50, /**< abort when possible, don't leave tables corrupted */
+  THD_ABORT_ASAP=100,  /**< abort asap */
+};
+
+extern struct kill_statement_service_st {
+  enum thd_kill_levels (*thd_kill_level_func)(const MYSQL_THD);
+} *thd_kill_statement_service;
+
+/* backward compatibility helper */
+#define thd_killed(THD)   (thd_kill_level(THD) == THD_ABORT_ASAP)
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define thd_kill_level(THD) \
+        thd_kill_statement_service->thd_kill_level_func(THD)
+
+#else
+
+enum thd_kill_levels thd_kill_level(const MYSQL_THD);
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+