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slot.h File Reference
#include "fmgr.h"
#include "access/xlog.h"
#include "access/xlogreader.h"
#include "storage/condition_variable.h"
#include "storage/lwlock.h"
#include "storage/shmem.h"
#include "storage/spin.h"
Include dependency graph for slot.h:
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Data Structures

struct  ReplicationSlotPersistentData
 
struct  ReplicationSlot
 
struct  ReplicationSlotCtlData
 

Macros

#define SlotIsPhysical(slot)   (slot->data.database == InvalidOid)
 
#define SlotIsLogical(slot)   (slot->data.database != InvalidOid)
 

Typedefs

typedef enum
ReplicationSlotPersistency 
ReplicationSlotPersistency
 
typedef struct
ReplicationSlotPersistentData 
ReplicationSlotPersistentData
 
typedef struct ReplicationSlot ReplicationSlot
 
typedef struct
ReplicationSlotCtlData 
ReplicationSlotCtlData
 

Enumerations

enum  ReplicationSlotPersistency { RS_PERSISTENT, RS_EPHEMERAL, RS_TEMPORARY }
 

Functions

Size ReplicationSlotsShmemSize (void)
 
void ReplicationSlotsShmemInit (void)
 
void ReplicationSlotCreate (const char *name, bool db_specific, ReplicationSlotPersistency p)
 
void ReplicationSlotPersist (void)
 
void ReplicationSlotDrop (const char *name, bool nowait)
 
void ReplicationSlotAcquire (const char *name, bool nowait)
 
void ReplicationSlotRelease (void)
 
void ReplicationSlotCleanup (void)
 
void ReplicationSlotSave (void)
 
void ReplicationSlotMarkDirty (void)
 
bool ReplicationSlotValidateName (const char *name, int elevel)
 
void ReplicationSlotReserveWal (void)
 
void ReplicationSlotsComputeRequiredXmin (bool already_locked)
 
void ReplicationSlotsComputeRequiredLSN (void)
 
XLogRecPtr ReplicationSlotsComputeLogicalRestartLSN (void)
 
bool ReplicationSlotsCountDBSlots (Oid dboid, int *nslots, int *nactive)
 
void ReplicationSlotsDropDBSlots (Oid dboid)
 
void StartupReplicationSlots (void)
 
void CheckPointReplicationSlots (void)
 
void CheckSlotRequirements (void)
 

Variables

ReplicationSlotCtlDataReplicationSlotCtl
 
PGDLLIMPORT ReplicationSlotMyReplicationSlot
 
PGDLLIMPORT int max_replication_slots
 

Macro Definition Documentation

#define SlotIsPhysical (   slot)    (slot->data.database == InvalidOid)

Definition at line 141 of file slot.h.

Referenced by CreateDecodingContext(), and CreateInitDecodingContext().

Typedef Documentation

Enumeration Type Documentation

Enumerator
RS_PERSISTENT 
RS_EPHEMERAL 
RS_TEMPORARY 

Definition at line 33 of file slot.h.

34 {
ReplicationSlotPersistency
Definition: slot.h:33

Function Documentation

void CheckPointReplicationSlots ( void  )

Definition at line 1055 of file slot.c.

References ReplicationSlot::data, DEBUG1, elog, i, ReplicationSlot::in_use, LOG, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, MAXPGPATH, ReplicationSlotPersistentData::name, NameStr, ReplicationSlotCtlData::replication_slots, and SaveSlotToPath().

Referenced by CheckPointGuts().

1056 {
1057  int i;
1058 
1059  elog(DEBUG1, "performing replication slot checkpoint");
1060 
1061  /*
1062  * Prevent any slot from being created/dropped while we're active. As we
1063  * explicitly do *not* want to block iterating over replication_slots or
1064  * acquiring a slot we cannot take the control lock - but that's OK,
1065  * because holding ReplicationSlotAllocationLock is strictly stronger, and
1066  * enough to guarantee that nobody can change the in_use bits on us.
1067  */
1068  LWLockAcquire(ReplicationSlotAllocationLock, LW_SHARED);
1069 
1070  for (i = 0; i < max_replication_slots; i++)
1071  {
1073  char path[MAXPGPATH];
1074 
1075  if (!s->in_use)
1076  continue;
1077 
1078  /* save the slot to disk, locking is handled in SaveSlotToPath() */
1079  sprintf(path, "pg_replslot/%s", NameStr(s->data.name));
1080  SaveSlotToPath(s, path, LOG);
1081  }
1082  LWLockRelease(ReplicationSlotAllocationLock);
1083 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
#define DEBUG1
Definition: elog.h:25
ReplicationSlotPersistentData data
Definition: slot.h:120
#define LOG
Definition: elog.h:26
static void SaveSlotToPath(ReplicationSlot *slot, const char *path, int elevel)
Definition: slot.c:1210
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define MAXPGPATH
bool in_use
Definition: slot.h:96
int max_replication_slots
Definition: slot.c:99
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
int i
#define NameStr(name)
Definition: c.h:493
ReplicationSlot replication_slots[1]
Definition: slot.h:153
#define elog
Definition: elog.h:219
void CheckSlotRequirements ( void  )

Definition at line 965 of file slot.c.

References ereport, errcode(), errmsg(), ERROR, max_replication_slots, wal_level, and WAL_LEVEL_REPLICA.

Referenced by CheckLogicalDecodingRequirements(), pg_create_physical_replication_slot(), and pg_drop_replication_slot().

966 {
967  if (max_replication_slots == 0)
968  ereport(ERROR,
969  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
970  (errmsg("replication slots can only be used if max_replication_slots > 0"))));
971 
973  ereport(ERROR,
974  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
975  errmsg("replication slots can only be used if wal_level >= replica")));
976 }
int wal_level
Definition: xlog.c:104
int errcode(int sqlerrcode)
Definition: elog.c:575
#define ERROR
Definition: elog.h:43
#define ereport(elevel, rest)
Definition: elog.h:122
int max_replication_slots
Definition: slot.c:99
int errmsg(const char *fmt,...)
Definition: elog.c:797
void ReplicationSlotAcquire ( const char *  name,
bool  nowait 
)

Definition at line 330 of file slot.c.

References ReplicationSlot::active_cv, ReplicationSlot::active_pid, Assert, ConditionVariableBroadcast(), ConditionVariableCancelSleep(), ConditionVariablePrepareToSleep(), ConditionVariableSleep(), ReplicationSlot::data, ereport, errcode(), errmsg(), ERROR, i, ReplicationSlot::in_use, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, MyProcPid, ReplicationSlotPersistentData::name, NameStr, ReplicationSlotCtlData::replication_slots, SpinLockAcquire, SpinLockRelease, and WAIT_EVENT_REPLICATION_SLOT_DROP.

Referenced by pg_logical_slot_get_changes_guts(), ReplicationSlotDrop(), StartLogicalReplication(), and StartReplication().

331 {
332  ReplicationSlot *slot;
333  int active_pid;
334  int i;
335 
336 retry:
337  Assert(MyReplicationSlot == NULL);
338 
339  /*
340  * Search for the named slot and mark it active if we find it. If the
341  * slot is already active, we exit the loop with active_pid set to the PID
342  * of the backend that owns it.
343  */
344  active_pid = 0;
345  slot = NULL;
346  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
347  for (i = 0; i < max_replication_slots; i++)
348  {
350 
351  if (s->in_use && strcmp(name, NameStr(s->data.name)) == 0)
352  {
353  /*
354  * This is the slot we want. We don't know yet if it's active, so
355  * get ready to sleep on it in case it is. (We may end up not
356  * sleeping, but we don't want to do this while holding the
357  * spinlock.)
358  */
360 
361  SpinLockAcquire(&s->mutex);
362 
363  active_pid = s->active_pid;
364  if (active_pid == 0)
365  active_pid = s->active_pid = MyProcPid;
366 
367  SpinLockRelease(&s->mutex);
368  slot = s;
369 
370  break;
371  }
372  }
373  LWLockRelease(ReplicationSlotControlLock);
374 
375  /* If we did not find the slot, error out. */
376  if (slot == NULL)
377  ereport(ERROR,
378  (errcode(ERRCODE_UNDEFINED_OBJECT),
379  errmsg("replication slot \"%s\" does not exist", name)));
380 
381  /*
382  * If we found the slot but it's already active in another backend, we
383  * either error out or retry after a short wait, as caller specified.
384  */
385  if (active_pid != MyProcPid)
386  {
387  if (nowait)
388  ereport(ERROR,
389  (errcode(ERRCODE_OBJECT_IN_USE),
390  errmsg("replication slot \"%s\" is active for PID %d",
391  name, active_pid)));
392 
393  /* Wait here until we get signaled, and then restart */
397  goto retry;
398  }
399  else
400  ConditionVariableCancelSleep(); /* no sleep needed after all */
401 
402  /* Let everybody know we've modified this slot */
404 
405  /* We made this slot active, so it's ours now. */
406  MyReplicationSlot = slot;
407 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
int MyProcPid
Definition: globals.c:39
int ConditionVariableBroadcast(ConditionVariable *cv)
int errcode(int sqlerrcode)
Definition: elog.c:575
ReplicationSlotPersistentData data
Definition: slot.h:120
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
void ConditionVariablePrepareToSleep(ConditionVariable *cv)
#define SpinLockAcquire(lock)
Definition: spin.h:62
void ConditionVariableCancelSleep(void)
#define ERROR
Definition: elog.h:43
#define ereport(elevel, rest)
Definition: elog.h:122
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
int max_replication_slots
Definition: slot.c:99
void ConditionVariableSleep(ConditionVariable *cv, uint32 wait_event_info)
#define Assert(condition)
Definition: c.h:664
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
ConditionVariable active_cv
Definition: slot.h:126
const char * name
Definition: encode.c:521
int errmsg(const char *fmt,...)
Definition: elog.c:797
pid_t active_pid
Definition: slot.h:99
int i
#define NameStr(name)
Definition: c.h:493
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
void ReplicationSlotCleanup ( void  )

Definition at line 471 of file slot.c.

References ReplicationSlot::active_cv, ReplicationSlot::active_pid, Assert, ConditionVariableBroadcast(), ReplicationSlot::data, i, ReplicationSlot::in_use, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, MyProcPid, ReplicationSlotPersistentData::persistency, ReplicationSlotCtlData::replication_slots, ReplicationSlotDropPtr(), RS_TEMPORARY, SpinLockAcquire, and SpinLockRelease.

Referenced by PostgresMain(), ProcKill(), and WalSndErrorCleanup().

472 {
473  int i;
474 
475  Assert(MyReplicationSlot == NULL);
476 
477 restart:
478  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
479  for (i = 0; i < max_replication_slots; i++)
480  {
482 
483  if (!s->in_use)
484  continue;
485 
486  SpinLockAcquire(&s->mutex);
487  if (s->active_pid == MyProcPid)
488  {
490  SpinLockRelease(&s->mutex);
491  LWLockRelease(ReplicationSlotControlLock); /* avoid deadlock */
492 
494 
496  goto restart;
497  }
498  else
499  SpinLockRelease(&s->mutex);
500  }
501 
502  LWLockRelease(ReplicationSlotControlLock);
503 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
int MyProcPid
Definition: globals.c:39
int ConditionVariableBroadcast(ConditionVariable *cv)
ReplicationSlotPersistency persistency
Definition: slot.h:54
static void ReplicationSlotDropPtr(ReplicationSlot *slot)
Definition: slot.c:539
ReplicationSlotPersistentData data
Definition: slot.h:120
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define SpinLockAcquire(lock)
Definition: spin.h:62
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
int max_replication_slots
Definition: slot.c:99
#define Assert(condition)
Definition: c.h:664
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
ConditionVariable active_cv
Definition: slot.h:126
pid_t active_pid
Definition: slot.h:99
int i
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
void ReplicationSlotCreate ( const char *  name,
bool  db_specific,
ReplicationSlotPersistency  p 
)

Definition at line 221 of file slot.c.

References ReplicationSlot::active_cv, ReplicationSlot::active_pid, Assert, ReplicationSlot::candidate_catalog_xmin, ReplicationSlot::candidate_restart_lsn, ReplicationSlot::candidate_restart_valid, ReplicationSlot::candidate_xmin_lsn, ConditionVariableBroadcast(), CreateSlotOnDisk(), ReplicationSlot::data, ReplicationSlotPersistentData::database, ReplicationSlot::dirty, ReplicationSlot::effective_catalog_xmin, ReplicationSlot::effective_xmin, ereport, errcode(), ERRCODE_DUPLICATE_OBJECT, errhint(), errmsg(), ERROR, i, ReplicationSlot::in_use, InvalidOid, InvalidTransactionId, InvalidXLogRecPtr, ReplicationSlot::just_dirtied, LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, MyDatabaseId, MyProcPid, ReplicationSlotPersistentData::name, NAMEDATALEN, NameStr, ReplicationSlotPersistentData::persistency, ReplicationSlotCtlData::replication_slots, ReplicationSlotValidateName(), SpinLockAcquire, SpinLockRelease, and StrNCpy.

Referenced by CreateReplicationSlot(), pg_create_logical_replication_slot(), and pg_create_physical_replication_slot().

223 {
224  ReplicationSlot *slot = NULL;
225  int i;
226 
227  Assert(MyReplicationSlot == NULL);
228 
230 
231  /*
232  * If some other backend ran this code concurrently with us, we'd likely
233  * both allocate the same slot, and that would be bad. We'd also be at
234  * risk of missing a name collision. Also, we don't want to try to create
235  * a new slot while somebody's busy cleaning up an old one, because we
236  * might both be monkeying with the same directory.
237  */
238  LWLockAcquire(ReplicationSlotAllocationLock, LW_EXCLUSIVE);
239 
240  /*
241  * Check for name collision, and identify an allocatable slot. We need to
242  * hold ReplicationSlotControlLock in shared mode for this, so that nobody
243  * else can change the in_use flags while we're looking at them.
244  */
245  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
246  for (i = 0; i < max_replication_slots; i++)
247  {
249 
250  if (s->in_use && strcmp(name, NameStr(s->data.name)) == 0)
251  ereport(ERROR,
253  errmsg("replication slot \"%s\" already exists", name)));
254  if (!s->in_use && slot == NULL)
255  slot = s;
256  }
257  LWLockRelease(ReplicationSlotControlLock);
258 
259  /* If all slots are in use, we're out of luck. */
260  if (slot == NULL)
261  ereport(ERROR,
262  (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
263  errmsg("all replication slots are in use"),
264  errhint("Free one or increase max_replication_slots.")));
265 
266  /*
267  * Since this slot is not in use, nobody should be looking at any part of
268  * it other than the in_use field unless they're trying to allocate it.
269  * And since we hold ReplicationSlotAllocationLock, nobody except us can
270  * be doing that. So it's safe to initialize the slot.
271  */
272  Assert(!slot->in_use);
273  Assert(slot->active_pid == 0);
274 
275  /* first initialize persistent data */
276  memset(&slot->data, 0, sizeof(ReplicationSlotPersistentData));
278  slot->data.database = db_specific ? MyDatabaseId : InvalidOid;
279  slot->data.persistency = persistency;
280 
281  /* and then data only present in shared memory */
282  slot->just_dirtied = false;
283  slot->dirty = false;
290 
291  /*
292  * Create the slot on disk. We haven't actually marked the slot allocated
293  * yet, so no special cleanup is required if this errors out.
294  */
295  CreateSlotOnDisk(slot);
296 
297  /*
298  * We need to briefly prevent any other backend from iterating over the
299  * slots while we flip the in_use flag. We also need to set the active
300  * flag while holding the ControlLock as otherwise a concurrent
301  * SlotAcquire() could acquire the slot as well.
302  */
303  LWLockAcquire(ReplicationSlotControlLock, LW_EXCLUSIVE);
304 
305  slot->in_use = true;
306 
307  /* We can now mark the slot active, and that makes it our slot. */
308  SpinLockAcquire(&slot->mutex);
309  Assert(slot->active_pid == 0);
310  slot->active_pid = MyProcPid;
311  SpinLockRelease(&slot->mutex);
312  MyReplicationSlot = slot;
313 
314  LWLockRelease(ReplicationSlotControlLock);
315 
316  /*
317  * Now that the slot has been marked as in_use and active, it's safe to
318  * let somebody else try to allocate a slot.
319  */
320  LWLockRelease(ReplicationSlotAllocationLock);
321 
322  /* Let everybody know we've modified this slot */
324 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
TransactionId candidate_catalog_xmin
Definition: slot.h:135
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
int MyProcPid
Definition: globals.c:39
int errhint(const char *fmt,...)
Definition: elog.c:987
int ConditionVariableBroadcast(ConditionVariable *cv)
ReplicationSlotPersistency persistency
Definition: slot.h:54
int errcode(int sqlerrcode)
Definition: elog.c:575
ReplicationSlotPersistentData data
Definition: slot.h:120
static void CreateSlotOnDisk(ReplicationSlot *slot)
Definition: slot.c:1150
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define NAMEDATALEN
bool ReplicationSlotValidateName(const char *name, int elevel)
Definition: slot.c:174
#define SpinLockAcquire(lock)
Definition: spin.h:62
#define ERROR
Definition: elog.h:43
TransactionId effective_xmin
Definition: slot.h:116
XLogRecPtr candidate_restart_valid
Definition: slot.h:137
#define InvalidTransactionId
Definition: transam.h:31
#define ereport(elevel, rest)
Definition: elog.h:122
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
bool just_dirtied
Definition: slot.h:102
TransactionId effective_catalog_xmin
Definition: slot.h:117
Oid MyDatabaseId
Definition: globals.c:77
#define InvalidOid
Definition: postgres_ext.h:36
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
int max_replication_slots
Definition: slot.c:99
#define Assert(condition)
Definition: c.h:664
#define StrNCpy(dst, src, len)
Definition: c.h:819
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
ConditionVariable active_cv
Definition: slot.h:126
const char * name
Definition: encode.c:521
XLogRecPtr candidate_xmin_lsn
Definition: slot.h:136
int errmsg(const char *fmt,...)
Definition: elog.c:797
pid_t active_pid
Definition: slot.h:99
int i
#define NameStr(name)
Definition: c.h:493
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:32
bool dirty
Definition: slot.h:103
XLogRecPtr candidate_restart_lsn
Definition: slot.h:138
void ReplicationSlotDrop ( const char *  name,
bool  nowait 
)

Definition at line 509 of file slot.c.

References Assert, ReplicationSlotAcquire(), and ReplicationSlotDropAcquired().

Referenced by DropReplicationSlot(), and pg_drop_replication_slot().

510 {
511  Assert(MyReplicationSlot == NULL);
512 
513  ReplicationSlotAcquire(name, nowait);
514 
516 }
void ReplicationSlotAcquire(const char *name, bool nowait)
Definition: slot.c:330
static void ReplicationSlotDropAcquired(void)
Definition: slot.c:522
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
#define Assert(condition)
Definition: c.h:664
const char * name
Definition: encode.c:521
void ReplicationSlotMarkDirty ( void  )
void ReplicationSlotPersist ( void  )

Definition at line 673 of file slot.c.

References Assert, ReplicationSlot::data, ReplicationSlot::mutex, MyReplicationSlot, ReplicationSlotPersistentData::persistency, ReplicationSlotMarkDirty(), ReplicationSlotSave(), RS_PERSISTENT, SpinLockAcquire, and SpinLockRelease.

Referenced by CreateReplicationSlot(), and pg_create_logical_replication_slot().

674 {
676 
677  Assert(slot != NULL);
679 
680  SpinLockAcquire(&slot->mutex);
682  SpinLockRelease(&slot->mutex);
683 
686 }
ReplicationSlotPersistency persistency
Definition: slot.h:54
void ReplicationSlotSave(void)
Definition: slot.c:638
ReplicationSlotPersistentData data
Definition: slot.h:120
#define SpinLockAcquire(lock)
Definition: spin.h:62
#define SpinLockRelease(lock)
Definition: spin.h:64
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
#define Assert(condition)
Definition: c.h:664
slock_t mutex
Definition: slot.h:93
void ReplicationSlotMarkDirty(void)
Definition: slot.c:656
void ReplicationSlotRelease ( void  )

Definition at line 416 of file slot.c.

References ReplicationSlot::active_cv, ReplicationSlot::active_pid, Assert, ConditionVariableBroadcast(), ReplicationSlot::data, ReplicationSlot::effective_xmin, InvalidTransactionId, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), ReplicationSlot::mutex, MyPgXact, MyReplicationSlot, ReplicationSlotPersistentData::persistency, PROC_IN_LOGICAL_DECODING, ReplicationSlotDropAcquired(), ReplicationSlotsComputeRequiredXmin(), RS_EPHEMERAL, RS_PERSISTENT, SpinLockAcquire, SpinLockRelease, TransactionIdIsValid, PGXACT::vacuumFlags, and ReplicationSlotPersistentData::xmin.

Referenced by CreateReplicationSlot(), pg_create_logical_replication_slot(), pg_create_physical_replication_slot(), pg_logical_slot_get_changes_guts(), PostgresMain(), ProcKill(), StartLogicalReplication(), StartReplication(), and WalSndErrorCleanup().

417 {
419 
420  Assert(slot != NULL && slot->active_pid != 0);
421 
422  if (slot->data.persistency == RS_EPHEMERAL)
423  {
424  /*
425  * Delete the slot. There is no !PANIC case where this is allowed to
426  * fail, all that may happen is an incomplete cleanup of the on-disk
427  * data.
428  */
430  }
431 
432  /*
433  * If slot needed to temporarily restrain both data and catalog xmin to
434  * create the catalog snapshot, remove that temporary constraint.
435  * Snapshots can only be exported while the initial snapshot is still
436  * acquired.
437  */
438  if (!TransactionIdIsValid(slot->data.xmin) &&
440  {
441  SpinLockAcquire(&slot->mutex);
443  SpinLockRelease(&slot->mutex);
445  }
446 
447  if (slot->data.persistency == RS_PERSISTENT)
448  {
449  /*
450  * Mark persistent slot inactive. We're not freeing it, just
451  * disconnecting, but wake up others that may be waiting for it.
452  */
453  SpinLockAcquire(&slot->mutex);
454  slot->active_pid = 0;
455  SpinLockRelease(&slot->mutex);
457  }
458 
459  MyReplicationSlot = NULL;
460 
461  /* might not have been set when we've been a plain slot */
462  LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
464  LWLockRelease(ProcArrayLock);
465 }
#define PROC_IN_LOGICAL_DECODING
Definition: proc.h:57
int ConditionVariableBroadcast(ConditionVariable *cv)
ReplicationSlotPersistency persistency
Definition: slot.h:54
ReplicationSlotPersistentData data
Definition: slot.h:120
PGXACT * MyPgXact
Definition: proc.c:68
uint8 vacuumFlags
Definition: proc.h:230
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define SpinLockAcquire(lock)
Definition: spin.h:62
static void ReplicationSlotDropAcquired(void)
Definition: slot.c:522
TransactionId effective_xmin
Definition: slot.h:116
#define InvalidTransactionId
Definition: transam.h:31
TransactionId xmin
Definition: slot.h:62
#define SpinLockRelease(lock)
Definition: spin.h:64
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
#define Assert(condition)
Definition: c.h:664
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
ConditionVariable active_cv
Definition: slot.h:126
pid_t active_pid
Definition: slot.h:99
slock_t mutex
Definition: slot.h:93
#define TransactionIdIsValid(xid)
Definition: transam.h:41
void ReplicationSlotsComputeRequiredXmin(bool already_locked)
Definition: slot.c:695
void ReplicationSlotReserveWal ( void  )

Definition at line 985 of file slot.c.

References Assert, ReplicationSlot::data, GetRedoRecPtr(), GetXLogInsertRecPtr(), InvalidXLogRecPtr, LogStandbySnapshot(), MyReplicationSlot, RecoveryInProgress(), ReplicationSlotsComputeRequiredLSN(), ReplicationSlotPersistentData::restart_lsn, SlotIsLogical, XLByteToSeg, XLogFlush(), and XLogGetLastRemovedSegno().

Referenced by CreateInitDecodingContext(), CreateReplicationSlot(), and pg_create_physical_replication_slot().

986 {
988 
989  Assert(slot != NULL);
991 
992  /*
993  * The replication slot mechanism is used to prevent removal of required
994  * WAL. As there is no interlock between this routine and checkpoints, WAL
995  * segments could concurrently be removed when a now stale return value of
996  * ReplicationSlotsComputeRequiredLSN() is used. In the unlikely case that
997  * this happens we'll just retry.
998  */
999  while (true)
1000  {
1001  XLogSegNo segno;
1002 
1003  /*
1004  * For logical slots log a standby snapshot and start logical decoding
1005  * at exactly that position. That allows the slot to start up more
1006  * quickly.
1007  *
1008  * That's not needed (or indeed helpful) for physical slots as they'll
1009  * start replay at the last logged checkpoint anyway. Instead return
1010  * the location of the last redo LSN. While that slightly increases
1011  * the chance that we have to retry, it's where a base backup has to
1012  * start replay at.
1013  */
1014  if (!RecoveryInProgress() && SlotIsLogical(slot))
1015  {
1016  XLogRecPtr flushptr;
1017 
1018  /* start at current insert position */
1020 
1021  /* make sure we have enough information to start */
1022  flushptr = LogStandbySnapshot();
1023 
1024  /* and make sure it's fsynced to disk */
1025  XLogFlush(flushptr);
1026  }
1027  else
1028  {
1029  slot->data.restart_lsn = GetRedoRecPtr();
1030  }
1031 
1032  /* prevent WAL removal as fast as possible */
1034 
1035  /*
1036  * If all required WAL is still there, great, otherwise retry. The
1037  * slot should prevent further removal of WAL, unless there's a
1038  * concurrent ReplicationSlotsComputeRequiredLSN() after we've written
1039  * the new restart_lsn above, so normally we should never need to loop
1040  * more than twice.
1041  */
1042  XLByteToSeg(slot->data.restart_lsn, segno);
1043  if (XLogGetLastRemovedSegno() < segno)
1044  break;
1045  }
1046 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
ReplicationSlotPersistentData data
Definition: slot.h:120
bool RecoveryInProgress(void)
Definition: xlog.c:7920
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2757
XLogSegNo XLogGetLastRemovedSegno(void)
Definition: xlog.c:3793
void ReplicationSlotsComputeRequiredLSN(void)
Definition: slot.c:741
XLogRecPtr LogStandbySnapshot(void)
Definition: standby.c:909
XLogRecPtr GetXLogInsertRecPtr(void)
Definition: xlog.c:11159
uint64 XLogSegNo
Definition: xlogdefs.h:34
#define SlotIsLogical(slot)
Definition: slot.h:142
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
#define XLByteToSeg(xlrp, logSegNo)
uint64 XLogRecPtr
Definition: xlogdefs.h:21
#define Assert(condition)
Definition: c.h:664
XLogRecPtr restart_lsn
Definition: slot.h:73
XLogRecPtr GetRedoRecPtr(void)
Definition: xlog.c:8210
void ReplicationSlotSave ( void  )

Definition at line 638 of file slot.c.

References Assert, ReplicationSlot::data, ERROR, MAXPGPATH, ReplicationSlotPersistentData::name, NameStr, and SaveSlotToPath().

Referenced by CreateInitDecodingContext(), CreateReplicationSlot(), LogicalConfirmReceivedLocation(), pg_create_physical_replication_slot(), and ReplicationSlotPersist().

639 {
640  char path[MAXPGPATH];
641 
642  Assert(MyReplicationSlot != NULL);
643 
644  sprintf(path, "pg_replslot/%s", NameStr(MyReplicationSlot->data.name));
646 }
ReplicationSlotPersistentData data
Definition: slot.h:120
static void SaveSlotToPath(ReplicationSlot *slot, const char *path, int elevel)
Definition: slot.c:1210
#define ERROR
Definition: elog.h:43
#define MAXPGPATH
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
#define Assert(condition)
Definition: c.h:664
#define NameStr(name)
Definition: c.h:493
XLogRecPtr ReplicationSlotsComputeLogicalRestartLSN ( void  )

Definition at line 784 of file slot.c.

References ReplicationSlot::data, i, ReplicationSlot::in_use, InvalidXLogRecPtr, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, ReplicationSlotCtlData::replication_slots, ReplicationSlotPersistentData::restart_lsn, result, SlotIsLogical, SpinLockAcquire, and SpinLockRelease.

Referenced by CheckPointLogicalRewriteHeap(), and CheckPointSnapBuild().

785 {
787  int i;
788 
789  if (max_replication_slots <= 0)
790  return InvalidXLogRecPtr;
791 
792  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
793 
794  for (i = 0; i < max_replication_slots; i++)
795  {
796  ReplicationSlot *s;
797  XLogRecPtr restart_lsn;
798 
800 
801  /* cannot change while ReplicationSlotCtlLock is held */
802  if (!s->in_use)
803  continue;
804 
805  /* we're only interested in logical slots */
806  if (!SlotIsLogical(s))
807  continue;
808 
809  /* read once, it's ok if it increases while we're checking */
810  SpinLockAcquire(&s->mutex);
811  restart_lsn = s->data.restart_lsn;
812  SpinLockRelease(&s->mutex);
813 
814  if (result == InvalidXLogRecPtr ||
815  restart_lsn < result)
816  result = restart_lsn;
817  }
818 
819  LWLockRelease(ReplicationSlotControlLock);
820 
821  return result;
822 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
return result
Definition: formatting.c:1633
ReplicationSlotPersistentData data
Definition: slot.h:120
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define SpinLockAcquire(lock)
Definition: spin.h:62
#define SlotIsLogical(slot)
Definition: slot.h:142
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
int max_replication_slots
Definition: slot.c:99
uint64 XLogRecPtr
Definition: xlogdefs.h:21
XLogRecPtr restart_lsn
Definition: slot.h:73
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
int i
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
void ReplicationSlotsComputeRequiredLSN ( void  )

Definition at line 741 of file slot.c.

References Assert, ReplicationSlot::data, i, ReplicationSlot::in_use, InvalidXLogRecPtr, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, ReplicationSlotCtlData::replication_slots, ReplicationSlotPersistentData::restart_lsn, SpinLockAcquire, SpinLockRelease, and XLogSetReplicationSlotMinimumLSN().

Referenced by LogicalConfirmReceivedLocation(), PhysicalConfirmReceivedLocation(), ReplicationSlotDropPtr(), ReplicationSlotReserveWal(), and StartupReplicationSlots().

742 {
743  int i;
744  XLogRecPtr min_required = InvalidXLogRecPtr;
745 
746  Assert(ReplicationSlotCtl != NULL);
747 
748  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
749  for (i = 0; i < max_replication_slots; i++)
750  {
752  XLogRecPtr restart_lsn;
753 
754  if (!s->in_use)
755  continue;
756 
757  SpinLockAcquire(&s->mutex);
758  restart_lsn = s->data.restart_lsn;
759  SpinLockRelease(&s->mutex);
760 
761  if (restart_lsn != InvalidXLogRecPtr &&
762  (min_required == InvalidXLogRecPtr ||
763  restart_lsn < min_required))
764  min_required = restart_lsn;
765  }
766  LWLockRelease(ReplicationSlotControlLock);
767 
768  XLogSetReplicationSlotMinimumLSN(min_required);
769 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
ReplicationSlotPersistentData data
Definition: slot.h:120
void XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn)
Definition: xlog.c:2648
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define SpinLockAcquire(lock)
Definition: spin.h:62
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
int max_replication_slots
Definition: slot.c:99
uint64 XLogRecPtr
Definition: xlogdefs.h:21
#define Assert(condition)
Definition: c.h:664
XLogRecPtr restart_lsn
Definition: slot.h:73
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
int i
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
void ReplicationSlotsComputeRequiredXmin ( bool  already_locked)

Definition at line 695 of file slot.c.

References Assert, ReplicationSlot::effective_catalog_xmin, ReplicationSlot::effective_xmin, i, ReplicationSlot::in_use, InvalidTransactionId, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, ProcArraySetReplicationSlotXmin(), ReplicationSlotCtlData::replication_slots, SpinLockAcquire, SpinLockRelease, TransactionIdIsValid, and TransactionIdPrecedes().

Referenced by CreateInitDecodingContext(), LogicalConfirmReceivedLocation(), PhysicalReplicationSlotNewXmin(), ReplicationSlotDropPtr(), ReplicationSlotRelease(), and StartupReplicationSlots().

696 {
697  int i;
699  TransactionId agg_catalog_xmin = InvalidTransactionId;
700 
701  Assert(ReplicationSlotCtl != NULL);
702 
703  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
704 
705  for (i = 0; i < max_replication_slots; i++)
706  {
708  TransactionId effective_xmin;
709  TransactionId effective_catalog_xmin;
710 
711  if (!s->in_use)
712  continue;
713 
714  SpinLockAcquire(&s->mutex);
715  effective_xmin = s->effective_xmin;
716  effective_catalog_xmin = s->effective_catalog_xmin;
717  SpinLockRelease(&s->mutex);
718 
719  /* check the data xmin */
720  if (TransactionIdIsValid(effective_xmin) &&
721  (!TransactionIdIsValid(agg_xmin) ||
722  TransactionIdPrecedes(effective_xmin, agg_xmin)))
723  agg_xmin = effective_xmin;
724 
725  /* check the catalog xmin */
726  if (TransactionIdIsValid(effective_catalog_xmin) &&
727  (!TransactionIdIsValid(agg_catalog_xmin) ||
728  TransactionIdPrecedes(effective_catalog_xmin, agg_catalog_xmin)))
729  agg_catalog_xmin = effective_catalog_xmin;
730  }
731 
732  LWLockRelease(ReplicationSlotControlLock);
733 
734  ProcArraySetReplicationSlotXmin(agg_xmin, agg_catalog_xmin, already_locked);
735 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
uint32 TransactionId
Definition: c.h:391
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define SpinLockAcquire(lock)
Definition: spin.h:62
TransactionId effective_xmin
Definition: slot.h:116
#define InvalidTransactionId
Definition: transam.h:31
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
TransactionId effective_catalog_xmin
Definition: slot.h:117
int max_replication_slots
Definition: slot.c:99
#define Assert(condition)
Definition: c.h:664
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
int i
void ProcArraySetReplicationSlotXmin(TransactionId xmin, TransactionId catalog_xmin, bool already_locked)
Definition: procarray.c:2964
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
#define TransactionIdIsValid(xid)
Definition: transam.h:41
bool ReplicationSlotsCountDBSlots ( Oid  dboid,
int *  nslots,
int *  nactive 
)

Definition at line 833 of file slot.c.

References ReplicationSlot::active_pid, ReplicationSlot::data, ReplicationSlotPersistentData::database, i, ReplicationSlot::in_use, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, ReplicationSlotCtlData::replication_slots, SlotIsLogical, SpinLockAcquire, and SpinLockRelease.

Referenced by dropdb().

834 {
835  int i;
836 
837  *nslots = *nactive = 0;
838 
839  if (max_replication_slots <= 0)
840  return false;
841 
842  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
843  for (i = 0; i < max_replication_slots; i++)
844  {
845  ReplicationSlot *s;
846 
848 
849  /* cannot change while ReplicationSlotCtlLock is held */
850  if (!s->in_use)
851  continue;
852 
853  /* only logical slots are database specific, skip */
854  if (!SlotIsLogical(s))
855  continue;
856 
857  /* not our database, skip */
858  if (s->data.database != dboid)
859  continue;
860 
861  /* count slots with spinlock held */
862  SpinLockAcquire(&s->mutex);
863  (*nslots)++;
864  if (s->active_pid != 0)
865  (*nactive)++;
866  SpinLockRelease(&s->mutex);
867  }
868  LWLockRelease(ReplicationSlotControlLock);
869 
870  if (*nslots > 0)
871  return true;
872  return false;
873 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
ReplicationSlotPersistentData data
Definition: slot.h:120
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define SpinLockAcquire(lock)
Definition: spin.h:62
#define SlotIsLogical(slot)
Definition: slot.h:142
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
int max_replication_slots
Definition: slot.c:99
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
pid_t active_pid
Definition: slot.h:99
int i
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
void ReplicationSlotsDropDBSlots ( Oid  dboid)

Definition at line 889 of file slot.c.

References ReplicationSlot::active_pid, ReplicationSlot::data, ReplicationSlotPersistentData::database, ereport, errcode(), errmsg(), ERROR, i, ReplicationSlot::in_use, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_replication_slots, ReplicationSlot::mutex, MyProcPid, ReplicationSlotPersistentData::name, NameStr, ReplicationSlotCtlData::replication_slots, ReplicationSlotDropAcquired(), SlotIsLogical, SpinLockAcquire, and SpinLockRelease.

Referenced by dbase_redo(), and dropdb().

890 {
891  int i;
892 
893  if (max_replication_slots <= 0)
894  return;
895 
896 restart:
897  LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
898  for (i = 0; i < max_replication_slots; i++)
899  {
900  ReplicationSlot *s;
901  char *slotname;
902  int active_pid;
903 
905 
906  /* cannot change while ReplicationSlotCtlLock is held */
907  if (!s->in_use)
908  continue;
909 
910  /* only logical slots are database specific, skip */
911  if (!SlotIsLogical(s))
912  continue;
913 
914  /* not our database, skip */
915  if (s->data.database != dboid)
916  continue;
917 
918  /* acquire slot, so ReplicationSlotDropAcquired can be reused */
919  SpinLockAcquire(&s->mutex);
920  /* can't change while ReplicationSlotControlLock is held */
921  slotname = NameStr(s->data.name);
922  active_pid = s->active_pid;
923  if (active_pid == 0)
924  {
925  MyReplicationSlot = s;
926  s->active_pid = MyProcPid;
927  }
928  SpinLockRelease(&s->mutex);
929 
930  /*
931  * Even though we hold an exclusive lock on the database object a
932  * logical slot for that DB can still be active, e.g. if it's
933  * concurrently being dropped by a backend connected to another DB.
934  *
935  * That's fairly unlikely in practice, so we'll just bail out.
936  */
937  if (active_pid)
938  ereport(ERROR,
939  (errcode(ERRCODE_OBJECT_IN_USE),
940  errmsg("replication slot \"%s\" is active for PID %d",
941  slotname, active_pid)));
942 
943  /*
944  * To avoid duplicating ReplicationSlotDropAcquired() and to avoid
945  * holding ReplicationSlotControlLock over filesystem operations,
946  * release ReplicationSlotControlLock and use
947  * ReplicationSlotDropAcquired.
948  *
949  * As that means the set of slots could change, restart scan from the
950  * beginning each time we release the lock.
951  */
952  LWLockRelease(ReplicationSlotControlLock);
954  goto restart;
955  }
956  LWLockRelease(ReplicationSlotControlLock);
957 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
int MyProcPid
Definition: globals.c:39
int errcode(int sqlerrcode)
Definition: elog.c:575
ReplicationSlotPersistentData data
Definition: slot.h:120
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1721
#define SpinLockAcquire(lock)
Definition: spin.h:62
static void ReplicationSlotDropAcquired(void)
Definition: slot.c:522
#define ERROR
Definition: elog.h:43
#define SlotIsLogical(slot)
Definition: slot.h:142
#define ereport(elevel, rest)
Definition: elog.h:122
bool in_use
Definition: slot.h:96
#define SpinLockRelease(lock)
Definition: spin.h:64
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
int max_replication_slots
Definition: slot.c:99
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1117
int errmsg(const char *fmt,...)
Definition: elog.c:797
pid_t active_pid
Definition: slot.h:99
int i
#define NameStr(name)
Definition: c.h:493
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
void ReplicationSlotsShmemInit ( void  )

Definition at line 132 of file slot.c.

References ReplicationSlot::active_cv, ConditionVariableInit(), i, ReplicationSlot::io_in_progress_lock, LWLockInitialize(), LWLockRegisterTranche(), LWTRANCHE_REPLICATION_SLOT_IO_IN_PROGRESS, max_replication_slots, MemSet, ReplicationSlot::mutex, ReplicationSlotCtlData::replication_slots, ReplicationSlotsShmemSize(), ShmemInitStruct(), and SpinLockInit.

Referenced by CreateSharedMemoryAndSemaphores().

133 {
134  bool found;
135 
136  if (max_replication_slots == 0)
137  return;
138 
140  ShmemInitStruct("ReplicationSlot Ctl", ReplicationSlotsShmemSize(),
141  &found);
142 
144  "replication_slot_io");
145 
146  if (!found)
147  {
148  int i;
149 
150  /* First time through, so initialize */
152 
153  for (i = 0; i < max_replication_slots; i++)
154  {
156 
157  /* everything else is zeroed by the memset above */
158  SpinLockInit(&slot->mutex);
161  }
162  }
163 }
ReplicationSlotCtlData * ReplicationSlotCtl
Definition: slot.c:93
Size ReplicationSlotsShmemSize(void)
Definition: slot.c:114
#define SpinLockInit(lock)
Definition: spin.h:60
#define MemSet(start, val, len)
Definition: c.h:846
void ConditionVariableInit(ConditionVariable *cv)
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:372
void LWLockInitialize(LWLock *lock, int tranche_id)
Definition: lwlock.c:673
int max_replication_slots
Definition: slot.c:99
void LWLockRegisterTranche(int tranche_id, char *tranche_name)
Definition: lwlock.c:598
ConditionVariable active_cv
Definition: slot.h:126
int i
ReplicationSlot replication_slots[1]
Definition: slot.h:153
slock_t mutex
Definition: slot.h:93
LWLock io_in_progress_lock
Definition: slot.h:123
Size ReplicationSlotsShmemSize ( void  )

Definition at line 114 of file slot.c.

References add_size(), max_replication_slots, mul_size(), and offsetof.

Referenced by CreateSharedMemoryAndSemaphores(), and ReplicationSlotsShmemInit().

115 {
116  Size size = 0;
117 
118  if (max_replication_slots == 0)
119  return size;
120 
121  size = offsetof(ReplicationSlotCtlData, replication_slots);
122  size = add_size(size,
124 
125  return size;
126 }
Size mul_size(Size s1, Size s2)
Definition: shmem.c:492
Size add_size(Size s1, Size s2)
Definition: shmem.c:475
int max_replication_slots
Definition: slot.c:99
size_t Size
Definition: c.h:350
#define offsetof(type, field)
Definition: c.h:549
bool ReplicationSlotValidateName ( const char *  name,
int  elevel 
)

Definition at line 174 of file slot.c.

References ereport, errcode(), errhint(), errmsg(), and NAMEDATALEN.

Referenced by readRecoveryCommandFile(), ReplicationSlotCreate(), and StartupReorderBuffer().

175 {
176  const char *cp;
177 
178  if (strlen(name) == 0)
179  {
180  ereport(elevel,
181  (errcode(ERRCODE_INVALID_NAME),
182  errmsg("replication slot name \"%s\" is too short",
183  name)));
184  return false;
185  }
186 
187  if (strlen(name) >= NAMEDATALEN)
188  {
189  ereport(elevel,
190  (errcode(ERRCODE_NAME_TOO_LONG),
191  errmsg("replication slot name \"%s\" is too long",
192  name)));
193  return false;
194  }
195 
196  for (cp = name; *cp; cp++)
197  {
198  if (!((*cp >= 'a' && *cp <= 'z')
199  || (*cp >= '0' && *cp <= '9')
200  || (*cp == '_')))
201  {
202  ereport(elevel,
203  (errcode(ERRCODE_INVALID_NAME),
204  errmsg("replication slot name \"%s\" contains invalid character",
205  name),
206  errhint("Replication slot names may only contain lower case letters, numbers, and the underscore character.")));
207  return false;
208  }
209  }
210  return true;
211 }
int errhint(const char *fmt,...)
Definition: elog.c:987
int errcode(int sqlerrcode)
Definition: elog.c:575
#define NAMEDATALEN
#define ereport(elevel, rest)
Definition: elog.h:122
static int elevel
Definition: vacuumlazy.c:136
const char * name
Definition: encode.c:521
int errmsg(const char *fmt,...)
Definition: elog.c:797
void StartupReplicationSlots ( void  )

Definition at line 1090 of file slot.c.

References AllocateDir(), dirent::d_name, DEBUG1, elog, ereport, errcode_for_file_access(), errmsg(), FreeDir(), fsync_fname(), lstat, max_replication_slots, MAXPGPATH, pg_str_endswith(), ReadDir(), ReplicationSlotsComputeRequiredLSN(), ReplicationSlotsComputeRequiredXmin(), RestoreSlotFromDisk(), rmtree(), snprintf(), and WARNING.

Referenced by StartupXLOG().

1091 {
1092  DIR *replication_dir;
1093  struct dirent *replication_de;
1094 
1095  elog(DEBUG1, "starting up replication slots");
1096 
1097  /* restore all slots by iterating over all on-disk entries */
1098  replication_dir = AllocateDir("pg_replslot");
1099  while ((replication_de = ReadDir(replication_dir, "pg_replslot")) != NULL)
1100  {
1101  struct stat statbuf;
1102  char path[MAXPGPATH + 12];
1103 
1104  if (strcmp(replication_de->d_name, ".") == 0 ||
1105  strcmp(replication_de->d_name, "..") == 0)
1106  continue;
1107 
1108  snprintf(path, sizeof(path), "pg_replslot/%s", replication_de->d_name);
1109 
1110  /* we're only creating directories here, skip if it's not our's */
1111  if (lstat(path, &statbuf) == 0 && !S_ISDIR(statbuf.st_mode))
1112  continue;
1113 
1114  /* we crashed while a slot was being setup or deleted, clean up */
1115  if (pg_str_endswith(replication_de->d_name, ".tmp"))
1116  {
1117  if (!rmtree(path, true))
1118  {
1119  ereport(WARNING,
1121  errmsg("could not remove directory \"%s\"", path)));
1122  continue;
1123  }
1124  fsync_fname("pg_replslot", true);
1125  continue;
1126  }
1127 
1128  /* looks like a slot in a normal state, restore */
1129  RestoreSlotFromDisk(replication_de->d_name);
1130  }
1131  FreeDir(replication_dir);
1132 
1133  /* currently no slots exist, we're done. */
1134  if (max_replication_slots <= 0)
1135  return;
1136 
1137  /* Now that we have recovered all the data, compute replication xmin */
1140 }
static void RestoreSlotFromDisk(const char *name)
Definition: slot.c:1334
#define DEBUG1
Definition: elog.h:25
bool pg_str_endswith(const char *str, const char *end)
Definition: string.c:31
void fsync_fname(const char *fname, bool isdir)
Definition: fd.c:567
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
Definition: dirent.h:9
void ReplicationSlotsComputeRequiredLSN(void)
Definition: slot.c:741
Definition: dirent.c:25
#define MAXPGPATH
int errcode_for_file_access(void)
Definition: elog.c:598
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2335
#define ereport(elevel, rest)
Definition: elog.h:122
#define WARNING
Definition: elog.h:40
bool rmtree(const char *path, bool rmtopdir)
Definition: rmtree.c:36
int max_replication_slots
Definition: slot.c:99
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2401
int errmsg(const char *fmt,...)
Definition: elog.c:797
char d_name[MAX_PATH]
Definition: dirent.h:14
#define elog
Definition: elog.h:219
#define lstat(path, sb)
Definition: win32.h:262
void ReplicationSlotsComputeRequiredXmin(bool already_locked)
Definition: slot.c:695
int FreeDir(DIR *dir)
Definition: fd.c:2444

Variable Documentation

ReplicationSlotCtlData* ReplicationSlotCtl

Definition at line 93 of file slot.c.

Referenced by pg_get_replication_slots().