From 354bb40e75d94466e91fe6960523612c9d17ccfb Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Thu, 2 Nov 2017 23:11:29 +0300
Subject: Add implementation

---
 mysql/mysql/service_locking.h | 114 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 mysql/mysql/service_locking.h

(limited to 'mysql/mysql/service_locking.h')

diff --git a/mysql/mysql/service_locking.h b/mysql/mysql/service_locking.h
new file mode 100644
index 0000000..06f02d2
--- /dev/null
+++ b/mysql/mysql/service_locking.h
@@ -0,0 +1,114 @@
+/*
+  Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+
+  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 SERVICE_LOCKING_INCLUDED
+#define SERVICE_LOCKING_INCLUDED
+
+/*
+  This service provides support for taking read/write locks.
+  It is intended for use with fabric, but it is still a general
+  service. The locks are in a separate namespace from other
+  locks in the server, and there is also no interactions with
+  transactions (i.e. locks are not released on commit/abort).
+
+  These locks are implemented using the metadata lock (MDL) subsystem
+  and thus deadlocks involving locking service locks and other types
+  of metadata will be detected using the MDL deadlock detector.
+*/
+
+#ifdef __cplusplus
+class THD;
+#define MYSQL_THD THD*
+#else
+#define MYSQL_THD void*
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+  Types of locking service locks.
+  LOCKING_SERVICE_READ is compatible with LOCKING_SERVICE_READ.
+  All other combinations are incompatible.
+*/
+enum enum_locking_service_lock_type
+{ LOCKING_SERVICE_READ, LOCKING_SERVICE_WRITE };
+
+extern struct mysql_locking_service_st {
+  /**
+    Acquire locking service locks.
+
+    @param opaque_thd      Thread handle. If NULL, current_thd will be used.
+    @param lock_namespace  Namespace of the locks to acquire.
+    @param lock_names      Array of names of the locks to acquire.
+    @param lock_num        Number of elements in 'lock_names'.
+    @param lock_type       Lock type to acquire. LOCKING_SERVICE_READ or _WRITE.
+    @param lock_timeout    Number of seconds to wait before giving up.
+
+    @retval 1              Acquisition failed, error has been reported.
+    @retval 0              Acquisition successful, all locks acquired.
+
+    @note both lock_namespace and lock_names are limited to 64 characters max.
+    Names are compared using binary comparison.
+  */
+  int (*mysql_acquire_locks)(MYSQL_THD opaque_thd, const char* lock_namespace,
+                             const char**lock_names, size_t lock_num,
+                             enum enum_locking_service_lock_type lock_type,
+                             unsigned long lock_timeout);
+
+  /**
+    Release all lock service locks taken by the given connection
+    in the given namespace.
+
+    @param opaque_thd      Thread handle. If NULL, current_thd will be used.
+    @param lock_namespace  Namespace of the locks to release.
+
+    @retval 1              Release failed, error has been reported.
+    @retval 0              Release successful, all locks acquired.
+  */
+  int (*mysql_release_locks)(MYSQL_THD opaque_thd, const char* lock_namespace);
+} *mysql_locking_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define mysql_acquire_locking_service_locks(_THD, _NAMESPACE, _NAMES, _NUM, \
+                                            _TYPE, _TIMEOUT)            \
+  mysql_locking_service->mysql_acquire_locks(_THD, _NAMESPACE, _NAMES, _NUM, \
+                                             _TYPE, _TIMEOUT)
+#define mysql_release_locking_service_locks(_THD, _NAMESPACE) \
+  mysql_locking_service->mysql_release_locks(_THD, _NAMESPACE)
+
+#else
+
+int mysql_acquire_locking_service_locks(MYSQL_THD opaque_thd,
+                                        const char* lock_namespace,
+                                        const char**lock_names,
+                                        size_t lock_num,
+                                        enum enum_locking_service_lock_type lock_type,
+                                        unsigned long lock_timeout);
+
+int mysql_release_locking_service_locks(MYSQL_THD opaque_thd,
+                                        const char* lock_namespace);
+
+#endif /* MYSQL_DYNAMIC_PLUGIN */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SERVICE_LOCKING_INCLUDED */
-- 
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