shmem_internal.h

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/*-------------------------------------------------------------------------
 *
 * shmem_internal.h
 *    Internal functions related to shmem allocation
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/storage/shmem_internal.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef SHMEM_INTERNAL_H
#define SHMEM_INTERNAL_H
 
#include "storage/shmem.h"
#include "utils/hsearch.h"
 
/* Different kinds of shmem areas. */
typedef enum
{
    SHMEM_KIND_STRUCT = 0,      /* plain, contiguous area of memory */
    SHMEM_KIND_HASH,            /* a hash table */
    SHMEM_KIND_SLRU,            /* SLRU buffers and control structures */
} ShmemRequestKind;
 
/* shmem.c */
typedef struct PGShmemHeader PGShmemHeader; /* avoid including
                                             * storage/pg_shmem.h here */
extern void ShmemCallRequestCallbacks(void);
extern void InitShmemAllocator(PGShmemHeader *seghdr);
#ifdef EXEC_BACKEND
extern void AttachShmemAllocator(PGShmemHeader *seghdr);
#endif
extern void ResetShmemAllocator(void);
 
extern void ShmemRequestInternal(ShmemStructOpts *options, ShmemRequestKind kind);
 
extern size_t ShmemGetRequestedSize(void);
extern void ShmemInitRequested(void);
#ifdef EXEC_BACKEND
extern void ShmemAttachRequested(void);
#endif
 
extern PGDLLIMPORT Size pg_get_shmem_pagesize(void);
 
/* shmem_hash.c */
extern HTAB *shmem_hash_create(void *location, size_t size, bool found,
                               const char *name, int64 nelems, HASHCTL *infoP, int hash_flags);
extern void shmem_hash_init(void *location, ShmemStructOpts *base_options);
extern void shmem_hash_attach(void *location, ShmemStructOpts *base_options);
 
#endif                          /* SHMEM_INTERNAL_H */