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/*-------------------------------------------------------------------------
*
* resowner.h
* POSTGRES resource owner definitions.
*
* Query-lifespan resources are tracked by associating them with
* ResourceOwner objects. This provides a simple mechanism for ensuring
* that such resources are freed at the right time.
* See utils/resowner/README for more info.
*
*
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/utils/resowner.h
*
*-------------------------------------------------------------------------
*/
#ifndef RESOWNER_H
#define RESOWNER_H
/*
* ResourceOwner objects are an opaque data structure known only within
* resowner.c.
*/
typedef struct ResourceOwnerData *ResourceOwner;
/*
* Globally known ResourceOwners
*/
extern PGDLLIMPORT ResourceOwner CurrentResourceOwner;
extern PGDLLIMPORT ResourceOwner CurTransactionResourceOwner;
extern PGDLLIMPORT ResourceOwner TopTransactionResourceOwner;
extern PGDLLIMPORT ResourceOwner AuxProcessResourceOwner;
/*
* Resource releasing is done in three phases: pre-locks, locks, and
* post-locks. The pre-lock phase must release any resources that are
* visible to other backends (such as pinned buffers); this ensures that
* when we release a lock that another backend may be waiting on, it will
* see us as being fully out of our transaction. The post-lock phase
* should be used for backend-internal cleanup.
*/
typedef enum
{
RESOURCE_RELEASE_BEFORE_LOCKS,
RESOURCE_RELEASE_LOCKS,
RESOURCE_RELEASE_AFTER_LOCKS
} ResourceReleasePhase;
/*
* Dynamically loaded modules can get control during ResourceOwnerRelease
* by providing a callback of this form.
*/
typedef void (*ResourceReleaseCallback) (ResourceReleasePhase phase,
bool isCommit,
bool isTopLevel,
void *arg);
/*
* Functions in resowner.c
*/
/* generic routines */
extern ResourceOwner ResourceOwnerCreate(ResourceOwner parent,
const char *name);
extern void ResourceOwnerRelease(ResourceOwner owner,
ResourceReleasePhase phase,
bool isCommit,
bool isTopLevel);
extern void ResourceOwnerDelete(ResourceOwner owner);
extern ResourceOwner ResourceOwnerGetParent(ResourceOwner owner);
extern void ResourceOwnerNewParent(ResourceOwner owner,
ResourceOwner newparent);
extern void RegisterResourceReleaseCallback(ResourceReleaseCallback callback,
void *arg);
extern void UnregisterResourceReleaseCallback(ResourceReleaseCallback callback,
void *arg);
extern void CreateAuxProcessResourceOwner(void);
extern void ReleaseAuxProcessResources(bool isCommit);
#endif /* RESOWNER_H */
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