codekingpro/portable-devtools

1/*-------------------------------------------------------------------------2 *3 * sinval.h4 *	  POSTGRES shared cache invalidation communication definitions.5 *6 *7 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group8 * Portions Copyright (c) 1994, Regents of the University of California9 *10 * src/include/storage/sinval.h11 *12 *-------------------------------------------------------------------------13 */14#ifndef SINVAL_H15#define SINVAL_H16 17#include <signal.h>18 19#include "storage/relfilelocator.h"20 21/*22 * We support several types of shared-invalidation messages:23 *	* invalidate a specific tuple in a specific catcache24 *	* invalidate all catcache entries from a given system catalog25 *	* invalidate a relcache entry for a specific logical relation26 *	* invalidate all relcache entries27 *	* invalidate an smgr cache entry for a specific physical relation28 *	* invalidate the mapped-relation mapping for a given database29 *	* invalidate any saved snapshot that might be used to scan a given relation30 * More types could be added if needed.  The message type is identified by31 * the first "int8" field of the message struct.  Zero or positive means a32 * specific-catcache inval message (and also serves as the catcache ID field).33 * Negative values identify the other message types, as per codes below.34 *35 * Catcache inval events are initially driven by detecting tuple inserts,36 * updates and deletions in system catalogs (see CacheInvalidateHeapTuple).37 * An update can generate two inval events, one for the old tuple and one for38 * the new, but this is reduced to one event if the tuple's hash key doesn't39 * change.  Note that the inval events themselves don't actually say whether40 * the tuple is being inserted or deleted.  Also, since we transmit only a41 * hash key, there is a small risk of unnecessary invalidations due to chance42 * matches of hash keys.43 *44 * Note that some system catalogs have multiple caches on them (with different45 * indexes).  On detecting a tuple invalidation in such a catalog, separate46 * catcache inval messages must be generated for each of its caches, since47 * the hash keys will generally be different.48 *49 * Catcache, relcache, and snapshot invalidations are transactional, and so50 * are sent to other backends upon commit.  Internally to the generating51 * backend, they are also processed at CommandCounterIncrement so that later52 * commands in the same transaction see the new state.  The generating backend53 * also has to process them at abort, to flush out any cache state it's loaded54 * from no-longer-valid entries.55 *56 * smgr and relation mapping invalidations are non-transactional: they are57 * sent immediately when the underlying file change is made.58 */59 60typedef struct61{62	int8		id;				/* cache ID --- must be first */63	Oid			dbId;			/* database ID, or 0 if a shared relation */64	uint32		hashValue;		/* hash value of key for this catcache */65} SharedInvalCatcacheMsg;66 67#define SHAREDINVALCATALOG_ID	(-1)68 69typedef struct70{71	int8		id;				/* type field --- must be first */72	Oid			dbId;			/* database ID, or 0 if a shared catalog */73	Oid			catId;			/* ID of catalog whose contents are invalid */74} SharedInvalCatalogMsg;75 76#define SHAREDINVALRELCACHE_ID	(-2)77 78typedef struct79{80	int8		id;				/* type field --- must be first */81	Oid			dbId;			/* database ID, or 0 if a shared relation */82	Oid			relId;			/* relation ID, or 0 if whole relcache */83} SharedInvalRelcacheMsg;84 85#define SHAREDINVALSMGR_ID		(-3)86 87typedef struct88{89	/* note: field layout chosen to pack into 16 bytes */90	int8		id;				/* type field --- must be first */91	int8		backend_hi;		/* high bits of backend ID, if temprel */92	uint16		backend_lo;		/* low bits of backend ID, if temprel */93	RelFileLocator rlocator;	/* spcOid, dbOid, relNumber */94} SharedInvalSmgrMsg;95 96#define SHAREDINVALRELMAP_ID	(-4)97 98typedef struct99{100	int8		id;				/* type field --- must be first */101	Oid			dbId;			/* database ID, or 0 for shared catalogs */102} SharedInvalRelmapMsg;103 104#define SHAREDINVALSNAPSHOT_ID	(-5)105 106typedef struct107{108	int8		id;				/* type field --- must be first */109	Oid			dbId;			/* database ID, or 0 if a shared relation */110	Oid			relId;			/* relation ID */111} SharedInvalSnapshotMsg;112 113typedef union114{115	int8		id;				/* type field --- must be first */116	SharedInvalCatcacheMsg cc;117	SharedInvalCatalogMsg cat;118	SharedInvalRelcacheMsg rc;119	SharedInvalSmgrMsg sm;120	SharedInvalRelmapMsg rm;121	SharedInvalSnapshotMsg sn;122} SharedInvalidationMessage;123 124 125/* Counter of messages processed; don't worry about overflow. */126extern PGDLLIMPORT uint64 SharedInvalidMessageCounter;127 128extern PGDLLIMPORT volatile sig_atomic_t catchupInterruptPending;129 130extern void SendSharedInvalidMessages(const SharedInvalidationMessage *msgs,131									  int n);132extern void ReceiveSharedInvalidMessages(void (*invalFunction) (SharedInvalidationMessage *msg),133										 void (*resetFunction) (void));134 135/* signal handler for catchup events (PROCSIG_CATCHUP_INTERRUPT) */136extern void HandleCatchupInterrupt(void);137 138/*139 * enable/disable processing of catchup events directly from signal handler.140 * The enable routine first performs processing of any catchup events that141 * have occurred since the last disable.142 */143extern void ProcessCatchupInterrupt(void);144 145extern int	xactGetCommittedInvalidationMessages(SharedInvalidationMessage **msgs,146												 bool *RelcacheInitFileInval);147extern void ProcessCommittedInvalidationMessages(SharedInvalidationMessage *msgs,148												 int nmsgs, bool RelcacheInitFileInval,149												 Oid dbid, Oid tsid);150 151extern void LocalExecuteInvalidationMessage(SharedInvalidationMessage *msg);152 153#endif							/* SINVAL_H */154