1 /*-------------------------------------------------------------------------
2  *
3  * sharedfileset.h
4  *	  Shared temporary file management.
5  *
6  *
7  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/storage/sharedfileset.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 
15 #ifndef SHAREDFILESET_H
16 #define SHAREDFILESET_H
17 
18 #include "storage/dsm.h"
19 #include "storage/fd.h"
20 #include "storage/spin.h"
21 
22 /*
23  * A set of temporary files that can be shared by multiple backends.
24  */
25 typedef struct SharedFileSet
26 {
27 	pid_t		creator_pid;	/* PID of the creating process */
28 	uint32		number;			/* per-PID identifier */
29 	slock_t		mutex;			/* mutex protecting the reference count */
30 	int			refcnt;			/* number of attached backends */
31 	int			ntablespaces;	/* number of tablespaces to use */
32 	Oid			tablespaces[8]; /* OIDs of tablespaces to use. Assumes that
33 								 * it's rare that there more than temp
34 								 * tablespaces. */
35 } SharedFileSet;
36 
37 extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
38 extern void SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg);
39 extern File SharedFileSetCreate(SharedFileSet *fileset, const char *name);
40 extern File SharedFileSetOpen(SharedFileSet *fileset, const char *name,
41 							  int mode);
42 extern bool SharedFileSetDelete(SharedFileSet *fileset, const char *name,
43 								bool error_on_failure);
44 extern void SharedFileSetDeleteAll(SharedFileSet *fileset);
45 extern void SharedFileSetUnregister(SharedFileSet *input_fileset);
46 
47 #endif
48