MySQL 8.0.29
Source Code Documentation
sql_backup_lock.h
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17 GNU General Public License, version 2.0, for more details.
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21 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
22
23#ifndef SQL_LOCK_INCLUDED
24#define SQL_LOCK_INCLUDED
25
26#include <sys/types.h>
27
28#include "my_sqlcommand.h" // SQLCOM_LOCK_INSTANCE, SQLCOM_UNLOCK_INSTANCE
29#include "sql/sql_cmd.h" // Sql_cmd
30
31class THD;
32
33/**
34 Sql_cmd_lock_instance represents statement LOCK INSTANCE FOR BACKUP.
35*/
36
38 public:
39 /**
40 Execute LOCK INSTANCE statement once.
41
42 @param thd Thread handler
43
44 @returns false on success, true on error
45 */
46
47 bool execute(THD *thd) override;
48
51 }
52};
53
54/**
55 Sql_cmd_unlock_instance represents statement UNLOCK INSTANCE.
56*/
57
59 public:
60 /**
61 Execute UNLOCK INSTANCE statement once.
62
63 @param thd Thread handler
64
65 @returns false on success, true on error
66 */
67
68 bool execute(THD *thd) override;
69
72 }
73};
74
75/**
76 Acquire exclusive Backup Lock.
77
78 @param[in] thd Current thread context
79 @param[in] lock_wait_timeout How many seconds to wait before timeout.
80 @param[in] for_trx true if MDL duration is MDL_TRANSACTION
81 false if MDL duration is MDL_EXPLICIT
82
83 @return Operation status.
84 @retval false Success
85 @retval true Failure
86*/
87
88bool acquire_exclusive_backup_lock(THD *thd, unsigned long lock_wait_timeout,
89 bool for_trx);
90
91/**
92 Acquire shared Backup Lock.
93
94 @param[in] thd Current thread context
95 @param[in] lock_wait_timeout How many seconds to wait before timeout.
96 @param[in] for_trx true if MDL duration is MDL_TRANSACTION
97 false if MDL duration is MDL_EXPLICIT
98
99 @return Operation status.
100 @retval false Success
101 @retval true Failure
102*/
103
104bool acquire_shared_backup_lock(THD *thd, unsigned long lock_wait_timeout,
105 bool for_trx = true);
106
107/**
108 Release Backup Lock if it was acquired.
109
110 @param[in] thd Current thread context
111*/
112
113void release_backup_lock(THD *thd);
114
115/**
116 There are three possible results while checking if the instance is locked for
117 backup.
118*/
119
121 NOT_LOCKED = 0,
122 LOCKED = 1,
123 OOM = 2
124};
125
126/**
127 Check if this server instance is locked with Backup Lock. In fact, it checks
128 if any thread owns BACKUP_LOCK.
129
130 @param[in] thd Current thread context
131
132 @retval NOT_LOCKED Backup Lock is not acquired by any thread.
133 @retval LOCKED Backup Lock is acquired by a thread.
134 @retval OOM Error occurred (OOM) when checking lock ownership.
135*/
136
138
139#endif /* SQL_LOCK_INCLUDED */
Sql_cmd_lock_instance represents statement LOCK INSTANCE FOR BACKUP.
Definition: sql_backup_lock.h:37
bool execute(THD *thd) override
Execute LOCK INSTANCE statement once.
Definition: sql_backup_lock.cc:58
enum_sql_command sql_command_code() const override
Return the command code for this statement.
Definition: sql_backup_lock.h:49
Sql_cmd_unlock_instance represents statement UNLOCK INSTANCE.
Definition: sql_backup_lock.h:58
bool execute(THD *thd) override
Execute UNLOCK INSTANCE statement once.
Definition: sql_backup_lock.cc:71
enum_sql_command sql_command_code() const override
Return the command code for this statement.
Definition: sql_backup_lock.h:70
Representation of an SQL command.
Definition: sql_cmd.h:64
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_class.h:945
enum_sql_command
Definition: my_sqlcommand.h:45
@ SQLCOM_LOCK_INSTANCE
Definition: my_sqlcommand.h:200
@ SQLCOM_UNLOCK_INSTANCE
Definition: my_sqlcommand.h:201
Is_instance_backup_locked_result is_instance_backup_locked(THD *thd)
Check if this server instance is locked with Backup Lock.
Definition: sql_backup_lock.cc:148
bool acquire_shared_backup_lock(THD *thd, unsigned long lock_wait_timeout, bool for_trx=true)
Acquire shared Backup Lock.
bool acquire_exclusive_backup_lock(THD *thd, unsigned long lock_wait_timeout, bool for_trx)
Acquire exclusive Backup Lock.
void release_backup_lock(THD *thd)
Release Backup Lock if it was acquired.
Definition: sql_backup_lock.cc:117
Is_instance_backup_locked_result
There are three possible results while checking if the instance is locked for backup.
Definition: sql_backup_lock.h:120
Representation of an SQL command.