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4ed8f0913b
We've had repeated bugs in the area of handling SLRU wraparound in the past, some of which have caused data loss. Switching to an indexing system for SLRUs that does not wrap around should allow us to get rid of a whole bunch of problems and improve the overall reliability of the system. This particular patch however only changes the indexing and doesn't address the wraparound per se. This is going to be done in the following patches. Author: Maxim Orlov, Aleksander Alekseev, Alexander Korotkov, Teodor Sigaev Author: Nikita Glukhov, Pavel Borisov, Yura Sokolov Reviewed-by: Jacob Champion, Heikki Linnakangas, Alexander Korotkov Reviewed-by: Japin Li, Pavel Borisov, Tom Lane, Peter Eisentraut, Andres Freund Reviewed-by: Andrey Borodin, Dilip Kumar, Aleksander Alekseev Discussion: https://postgr.es/m/CACG%3DezZe1NQSCnfHOr78AtAZxJZeCvxrts0ygrxYwe%3DpyyjVWA%40mail.gmail.com Discussion: https://postgr.es/m/CAJ7c6TPDOYBYrnCAeyndkBktO0WG2xSdYduTF0nxq%2BvfkmTF5Q%40mail.gmail.com
66 lines
2 KiB
C
66 lines
2 KiB
C
/*-------------------------------------------------------------------------
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*
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* sync.h
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* File synchronization management code.
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*
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* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/storage/sync.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef SYNC_H
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#define SYNC_H
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#include "storage/relfilelocator.h"
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/*
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* Type of sync request. These are used to manage the set of pending
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* requests to call a sync handler's sync or unlink functions at the next
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* checkpoint.
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*/
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typedef enum SyncRequestType
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{
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SYNC_REQUEST, /* schedule a call of sync function */
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SYNC_UNLINK_REQUEST, /* schedule a call of unlink function */
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SYNC_FORGET_REQUEST, /* forget all calls for a tag */
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SYNC_FILTER_REQUEST, /* forget all calls satisfying match fn */
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} SyncRequestType;
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/*
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* Which set of functions to use to handle a given request. The values of
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* the enumerators must match the indexes of the function table in sync.c.
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*/
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typedef enum SyncRequestHandler
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{
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SYNC_HANDLER_MD = 0,
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SYNC_HANDLER_CLOG,
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SYNC_HANDLER_COMMIT_TS,
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SYNC_HANDLER_MULTIXACT_OFFSET,
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SYNC_HANDLER_MULTIXACT_MEMBER,
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SYNC_HANDLER_NONE,
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} SyncRequestHandler;
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/*
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* A tag identifying a file. Currently it has the members required for md.c's
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* usage, but sync.c has no knowledge of the internal structure, and it is
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* liable to change as required by future handlers.
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*/
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typedef struct FileTag
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{
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int16 handler; /* SyncRequestHandler value, saving space */
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int16 forknum; /* ForkNumber, saving space */
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RelFileLocator rlocator;
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uint64 segno;
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} FileTag;
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extern void InitSync(void);
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extern void SyncPreCheckpoint(void);
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extern void SyncPostCheckpoint(void);
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extern void ProcessSyncRequests(void);
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extern void RememberSyncRequest(const FileTag *ftag, SyncRequestType type);
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extern bool RegisterSyncRequest(const FileTag *ftag, SyncRequestType type,
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bool retryOnError);
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#endif /* SYNC_H */
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