1 /*-------------------------------------------------------------------------
2  *
3  * walsender_private.h
4  *	  Private definitions from replication/walsender.c.
5  *
6  * Portions Copyright (c) 2010-2016, PostgreSQL Global Development Group
7  *
8  * src/include/replication/walsender_private.h
9  *
10  *-------------------------------------------------------------------------
11  */
12 #ifndef _WALSENDER_PRIVATE_H
13 #define _WALSENDER_PRIVATE_H
14 
15 #include "access/xlog.h"
16 #include "nodes/nodes.h"
17 #include "replication/syncrep.h"
18 #include "storage/latch.h"
19 #include "storage/shmem.h"
20 #include "storage/spin.h"
21 
22 typedef enum WalSndState
23 {
24 	WALSNDSTATE_STARTUP = 0,
25 	WALSNDSTATE_BACKUP,
26 	WALSNDSTATE_CATCHUP,
27 	WALSNDSTATE_STREAMING,
28 	WALSNDSTATE_STOPPING
29 } WalSndState;
30 
31 /*
32  * Each walsender has a WalSnd struct in shared memory.
33  */
34 typedef struct WalSnd
35 {
36 	pid_t		pid;			/* this walsender's process id, or 0 */
37 	WalSndState state;			/* this walsender's state */
38 	XLogRecPtr	sentPtr;		/* WAL has been sent up to this point */
39 	bool		needreload;		/* does currently-open file need to be
40 								 * reloaded? */
41 
42 	/*
43 	 * The xlog locations that have been written, flushed, and applied by
44 	 * standby-side. These may be invalid if the standby-side has not offered
45 	 * values yet.
46 	 */
47 	XLogRecPtr	write;
48 	XLogRecPtr	flush;
49 	XLogRecPtr	apply;
50 
51 	/* Protects shared variables shown above. */
52 	slock_t		mutex;
53 
54 	/*
55 	 * Pointer to the walsender's latch. Used by backends to wake up this
56 	 * walsender when it has work to do. NULL if the walsender isn't active.
57 	 */
58 	Latch	   *latch;
59 
60 	/*
61 	 * The priority order of the standby managed by this WALSender, as listed
62 	 * in synchronous_standby_names, or 0 if not-listed. Protected by
63 	 * SyncRepLock.
64 	 */
65 	int			sync_standby_priority;
66 } WalSnd;
67 
68 extern WalSnd *MyWalSnd;
69 
70 /* There is one WalSndCtl struct for the whole database cluster */
71 typedef struct
72 {
73 	/*
74 	 * Synchronous replication queue with one queue per request type.
75 	 * Protected by SyncRepLock.
76 	 */
77 	SHM_QUEUE	SyncRepQueue[NUM_SYNC_REP_WAIT_MODE];
78 
79 	/*
80 	 * Current location of the head of the queue. All waiters should have a
81 	 * waitLSN that follows this value. Protected by SyncRepLock.
82 	 */
83 	XLogRecPtr	lsn[NUM_SYNC_REP_WAIT_MODE];
84 
85 	/*
86 	 * Are any sync standbys defined?  Waiting backends can't reload the
87 	 * config file safely, so checkpointer updates this value as needed.
88 	 * Protected by SyncRepLock.
89 	 */
90 	bool		sync_standbys_defined;
91 
92 	WalSnd		walsnds[FLEXIBLE_ARRAY_MEMBER];
93 } WalSndCtlData;
94 
95 extern WalSndCtlData *WalSndCtl;
96 
97 
98 extern void WalSndSetState(WalSndState state);
99 
100 /*
101  * Internal functions for parsing the replication grammar, in repl_gram.y and
102  * repl_scanner.l
103  */
104 extern int	replication_yyparse(void);
105 extern int	replication_yylex(void);
106 extern void replication_yyerror(const char *str) pg_attribute_noreturn();
107 extern void replication_scanner_init(const char *query_string);
108 extern void replication_scanner_finish(void);
109 
110 extern Node *replication_parse_result;
111 
112 #endif   /* _WALSENDER_PRIVATE_H */
113