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lockdefs.h
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1 /*-------------------------------------------------------------------------
2  *
3  * lockdefs.h
4  * Frontend exposed parts of postgres' low level lock mechanism
5  *
6  * The split between lockdefs.h and lock.h is not very principled. This file
7  * contains definition that have to (indirectly) be available when included by
8  * FRONTEND code.
9  *
10  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
11  * Portions Copyright (c) 1994, Regents of the University of California
12  *
13  * src/include/storage/lockdefs.h
14  *
15  *-------------------------------------------------------------------------
16  */
17 #ifndef LOCKDEFS_H_
18 #define LOCKDEFS_H_
19 
20 /*
21  * LOCKMODE is an integer (1..N) indicating a lock type. LOCKMASK is a bit
22  * mask indicating a set of held or requested lock types (the bit 1<<mode
23  * corresponds to a particular lock mode).
24  */
25 typedef int LOCKMASK;
26 typedef int LOCKMODE;
27 
28 /*
29  * These are the valid values of type LOCKMODE for all the standard lock
30  * methods (both DEFAULT and USER).
31  */
32 
33 /* NoLock is not a lock mode, but a flag value meaning "don't get a lock" */
34 #define NoLock 0
35 
36 #define AccessShareLock 1 /* SELECT */
37 #define RowShareLock 2 /* SELECT FOR UPDATE/FOR SHARE */
38 #define RowExclusiveLock 3 /* INSERT, UPDATE, DELETE */
39 #define ShareUpdateExclusiveLock 4 /* VACUUM (non-FULL),ANALYZE, CREATE
40  * INDEX CONCURRENTLY */
41 #define ShareLock 5 /* CREATE INDEX (WITHOUT CONCURRENTLY) */
42 #define ShareRowExclusiveLock 6 /* like EXCLUSIVE MODE, but allows ROW
43  * SHARE */
44 #define ExclusiveLock 7 /* blocks ROW SHARE/SELECT...FOR
45  * UPDATE */
46 #define AccessExclusiveLock 8 /* ALTER TABLE, DROP TABLE, VACUUM
47  * FULL, and unqualified LOCK TABLE */
48 
49 typedef struct xl_standby_lock
50 {
51  TransactionId xid; /* xid of holder of AccessExclusiveLock */
55 
56 #endif /* LOCKDEF_H_ */
uint32 TransactionId
Definition: c.h:397
int LOCKMODE
Definition: lockdefs.h:26
unsigned int Oid
Definition: postgres_ext.h:31
struct xl_standby_lock xl_standby_lock
TransactionId xid
Definition: lockdefs.h:51
int LOCKMASK
Definition: lockdefs.h:25