sharedfileset.h

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/*-------------------------------------------------------------------------
 *
 * sharedfileset.h
 *    Shared temporary file management.
 *
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/storage/sharedfileset.h
 *
 *-------------------------------------------------------------------------
 */

#ifndef SHAREDFILESET_H
#define SHAREDFILESET_H

#include "storage/dsm.h"
#include "storage/fd.h"
#include "storage/spin.h"

/*
 * A set of temporary files that can be shared by multiple backends.
 */
typedef struct SharedFileSet
{
    pid_t       creator_pid;    /* PID of the creating process */
    uint32      number;         /* per-PID identifier */
    slock_t     mutex;          /* mutex protecting the reference count */
    int         refcnt;         /* number of attached backends */
    int         ntablespaces;   /* number of tablespaces to use */
    Oid         tablespaces[8]; /* OIDs of tablespaces to use. Assumes that
                                 * it's rare that there more than temp
                                 * tablespaces. */
} SharedFileSet;

extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
extern void SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg);
extern File SharedFileSetCreate(SharedFileSet *fileset, const char *name);
extern File SharedFileSetOpen(SharedFileSet *fileset, const char *name);
extern bool SharedFileSetDelete(SharedFileSet *fileset, const char *name,
                                bool error_on_failure);
extern void SharedFileSetDeleteAll(SharedFileSet *fileset);

#endif