thd_rnd service

include/mysql/service_thd_rnd.h

@@ -0,0 +1,62 @@
+#ifndef MYSQL_SERVICE_THD_RND_INCLUDED
+/* Copyright (C) 2017 MariaDB Corporation
+
+   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 */
+
+/**
+  @file
+  This service provides access to the thd-local random number generator.
+
+  It's preferrable over the global one, because concurrent threads
+  can generate random numbers without fighting each other over the access
+  to the shared rnd state.
+*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef MYSQL_ABI_CHECK
+#include <stdlib.h>
+#endif
+
+extern struct thd_rnd_service_st {
+  double (*thd_rnd_ptr)(MYSQL_THD thd);
+  void   (*thd_c_r_p_ptr)(MYSQL_THD thd, char *to, size_t length);
+} *thd_rnd_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+#define thd_rnd(A) thd_rnd_service->thd_rnd_ptr(A)
+#define thd_create_random_password(A,B,C) thd_rnd_service->thd_c_r_p_ptr(A,B,C)
+#else
+
+double thd_rnd(MYSQL_THD thd);
+
+/**
+  Generate string of printable random characters of requested length.
+
+  @param to[out]      Buffer for generation; must be at least length+1 bytes
+                      long; result string is always null-terminated
+  @param length[in]   How many random characters to put in buffer
+*/
+void thd_create_random_password(MYSQL_THD thd, char *to, size_t length);
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MYSQL_SERVICE_THD_RND_INCLUDED
+#endif