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Diffstat (limited to 'mysql/mysql/service_locking.h')
| -rw-r--r-- | mysql/mysql/service_locking.h | 114 |
1 files changed, 114 insertions, 0 deletions
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 */ |