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/*-------------------------------------------------------------------------
*
* walsender_private.h
* Private definitions from replication/walsender.c.
*
* Portions Copyright (c) 2010-2021, PostgreSQL Global Development Group
*
* src/include/replication/walsender_private.h
*
*-------------------------------------------------------------------------
*/
#ifndef _WALSENDER_PRIVATE_H
#define _WALSENDER_PRIVATE_H
#include "access/xlog.h"
#include "nodes/nodes.h"
#include "replication/syncrep.h"
#include "storage/latch.h"
#include "storage/shmem.h"
#include "storage/spin.h"
typedef enum WalSndState
{
WALSNDSTATE_STARTUP = 0,
WALSNDSTATE_BACKUP,
WALSNDSTATE_CATCHUP,
WALSNDSTATE_STREAMING,
WALSNDSTATE_STOPPING
} WalSndState;
/*
* Each walsender has a WalSnd struct in shared memory.
*
* This struct is protected by its 'mutex' spinlock field, except that some
* members are only written by the walsender process itself, and thus that
* process is free to read those members without holding spinlock. pid and
* needreload always require the spinlock to be held for all accesses.
*/
typedef struct WalSnd
{
pid_t pid; /* this walsender's PID, or 0 if not active */
WalSndState state; /* this walsender's state */
XLogRecPtr sentPtr; /* WAL has been sent up to this point */
bool needreload; /* does currently-open file need to be
* reloaded? */
/*
* 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;
/* Measured lag times, or -1 for unknown/none. */
TimeOffset writeLag;
TimeOffset flushLag;
TimeOffset applyLag;
/*
* The priority order of the standby managed by this WALSender, as listed
* in synchronous_standby_names, or 0 if not-listed.
*/
int sync_standby_priority;
/* Protects shared variables shown above. */
slock_t mutex;
/*
* Pointer to the walsender's latch. Used by backends to wake up this
* walsender when it has work to do. NULL if the walsender isn't active.
*/
Latch *latch;
/*
* Timestamp of the last message received from standby.
*/
TimestampTz replyTime;
} WalSnd;
extern WalSnd *MyWalSnd;
/* There is one WalSndCtl struct for the whole database cluster */
typedef struct
{
/*
* Synchronous replication queue with one queue per request type.
* Protected by SyncRepLock.
*/
SHM_QUEUE SyncRepQueue[NUM_SYNC_REP_WAIT_MODE];
/*
* Current location of the head of the queue. All waiters should have a
* waitLSN that follows this value. Protected by SyncRepLock.
*/
XLogRecPtr lsn[NUM_SYNC_REP_WAIT_MODE];
/*
* Are any sync standbys defined? Waiting backends can't reload the
* config file safely, so checkpointer updates this value as needed.
* Protected by SyncRepLock.
*/
bool sync_standbys_defined;
WalSnd walsnds[FLEXIBLE_ARRAY_MEMBER];
} WalSndCtlData;
extern WalSndCtlData *WalSndCtl;
extern void WalSndSetState(WalSndState state);
/*
* 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) pg_attribute_noreturn();
extern void replication_scanner_init(const char *query_string);
extern void replication_scanner_finish(void);
extern bool replication_scanner_is_replication_command(void);
extern Node *replication_parse_result;
#endif /* _WALSENDER_PRIVATE_H */
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