mirror of https://github.com/citusdata/citus.git
79 lines
2.4 KiB
C
79 lines
2.4 KiB
C
/*-------------------------------------------------------------------------
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*
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* resource_lock.h
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* Locking Infrastructure for CitusDB.
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*
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* Copyright (c) 2012-2015, Citus Data, Inc.
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*-------------------------------------------------------------------------
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*/
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#ifndef RESOURCE_LOCK_H
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#define RESOURCE_LOCK_H
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#include "postgres.h" /* IWYU pragma: keep */
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#include "c.h"
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#include "storage/lock.h"
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/*
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* Postgres' advisory locks use 'field4' to discern between different kind of
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* advisory locks. Only 1 and 2 are used allowing us to define non-conflicting
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* lock methods.
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*
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* In case postgres starts to use additional values, CitusDB's values
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* will have to be changed. That just requires re-compiling and a restart.
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*/
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typedef enum AdvisoryLocktagClass
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{
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/* values defined in postgres' lockfuncs.c */
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ADV_LOCKTAG_CLASS_INT64 = 1,
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ADV_LOCKTAG_CLASS_INT32 = 2,
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/* CitusDB lock types */
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ADV_LOCKTAG_CLASS_CITUS_SHARD_METADATA = 4,
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ADV_LOCKTAG_CLASS_CITUS_SHARD = 5,
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ADV_LOCKTAG_CLASS_CITUS_JOB = 6
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} AdvisoryLocktagClass;
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/* reuse advisory lock, but with different, unused field 4 (4)*/
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#define SET_LOCKTAG_SHARD_METADATA_RESOURCE(tag, db, shardid) \
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SET_LOCKTAG_ADVISORY(tag, \
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db, \
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(uint32) ((shardid) >> 32), \
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(uint32) (shardid), \
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ADV_LOCKTAG_CLASS_CITUS_SHARD_METADATA)
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/* reuse advisory lock, but with different, unused field 4 (5)*/
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#define SET_LOCKTAG_SHARD_RESOURCE(tag, db, shardid) \
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SET_LOCKTAG_ADVISORY(tag, \
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db, \
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(uint32) ((shardid) >> 32), \
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(uint32) (shardid), \
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ADV_LOCKTAG_CLASS_CITUS_SHARD)
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/* reuse advisory lock, but with different, unused field 4 (6) */
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#define SET_LOCKTAG_JOB_RESOURCE(tag, db, jobid) \
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SET_LOCKTAG_ADVISORY(tag, \
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db, \
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(uint32) ((jobid) >> 32), \
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(uint32) (jobid), \
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ADV_LOCKTAG_CLASS_CITUS_JOB)
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/* Lock shard/relation metadata for safe modifications */
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extern void LockShardDistributionMetadata(int64 shardId, LOCKMODE lockMode);
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extern void LockRelationDistributionMetadata(Oid relationId, LOCKMODE lockMode);
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/* Lock shard data, for DML commands or remote fetches */
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extern void LockShardResource(uint64 shardId, LOCKMODE lockmode);
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extern void UnlockShardResource(uint64 shardId, LOCKMODE lockmode);
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/* Lock a job schema or partition task directory */
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extern void LockJobResource(uint64 jobId, LOCKMODE lockmode);
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extern void UnlockJobResource(uint64 jobId, LOCKMODE lockmode);
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#endif /* RESOURCE_LOCK_H */
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