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/*-------------------------------------------------------------------------
*
* walsender.h
* Exports from replication/walsender.c.
*
* Portions Copyright (c) 2010-2011, PostgreSQL Global Development Group
*
* src/include/replication/walsender.h
*
*-------------------------------------------------------------------------
*/
#ifndef _WALSENDER_H
#define _WALSENDER_H
#include "access/xlog.h"
#include "nodes/nodes.h"
#include "storage/latch.h"
#include "replication/syncrep.h"
#include "storage/spin.h"
typedef enum WalSndState
{
WALSNDSTATE_STARTUP = 0,
WALSNDSTATE_BACKUP,
WALSNDSTATE_CATCHUP,
WALSNDSTATE_STREAMING
} WalSndState;
/*
* Each walsender has a WalSnd struct in shared memory.
*/
typedef struct WalSnd
{
pid_t pid; /* this walsender's process id, or 0 */
WalSndState state; /* this walsender's state */
XLogRecPtr sentPtr; /* WAL has been sent up to this point */
/*
* The xlog locations that have been written, flushed, and applied by
* standby-side. These may be invalid if the standby-side has not offered
* values yet.
*/
XLogRecPtr write;
XLogRecPtr flush;
XLogRecPtr apply;
/* Protects shared variables shown above. */
slock_t mutex;
/*
* Latch used by backends to wake up this walsender when it has work to
* do.
*/
Latch latch;
/*
* The priority order of the standby managed by this WALSender, as listed
* in synchronous_standby_names, or 0 if not-listed. Protected by
* SyncRepLock.
*/
int sync_standby_priority;
} WalSnd;
extern WalSnd *MyWalSnd;
/* There is one WalSndCtl struct for the whole database cluster */
typedef struct
{
/*
* Synchronous replication queue. Protected by SyncRepLock.
*/
SHM_QUEUE SyncRepQueue;
/*
* Current location of the head of the queue. All waiters should have a
* waitLSN that follows this value. Protected by SyncRepLock.
*/
XLogRecPtr lsn;
/*
* Are any sync standbys defined? Waiting backends can't reload the
* config file safely, so WAL writer updates this value as needed.
* Protected by SyncRepLock.
*/
bool sync_standbys_defined;
WalSnd walsnds[1]; /* VARIABLE LENGTH ARRAY */
} WalSndCtlData;
extern WalSndCtlData *WalSndCtl;
/* global state */
extern bool am_walsender;
extern volatile sig_atomic_t walsender_shutdown_requested;
extern volatile sig_atomic_t walsender_ready_to_stop;
/* user-settable parameters */
extern int WalSndDelay;
extern int max_wal_senders;
extern int replication_timeout;
extern int WalSenderMain(void);
extern void WalSndSignals(void);
extern Size WalSndShmemSize(void);
extern void WalSndShmemInit(void);
extern void WalSndWakeup(void);
extern void WalSndSetState(WalSndState state);
extern void XLogRead(char *buf, XLogRecPtr recptr, Size nbytes);
extern Datum pg_stat_get_wal_senders(PG_FUNCTION_ARGS);
/*
* Internal functions for parsing the replication grammar, in repl_gram.y and
* repl_scanner.l
*/
extern int replication_yyparse(void);
extern int replication_yylex(void);
extern void replication_yyerror(const char *str);
extern void replication_scanner_init(const char *query_string);
extern void replication_scanner_finish(void);
extern Node *replication_parse_result;
#endif /* _WALSENDER_H */
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