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dsm.h
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1 /*-------------------------------------------------------------------------
2  *
3  * dsm.h
4  * manage dynamic shared memory segments
5  *
6  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  * src/include/storage/dsm.h
10  *
11  *-------------------------------------------------------------------------
12  */
13 #ifndef DSM_H
14 #define DSM_H
15 
16 #include "storage/dsm_impl.h"
17 
18 typedef struct dsm_segment dsm_segment;
19 
20 #define DSM_CREATE_NULL_IF_MAXSEGMENTS 0x0001
21 
22 /* A sentinel value for an invalid DSM handle. */
23 #define DSM_HANDLE_INVALID 0
24 
25 /* Startup and shutdown functions. */
26 struct PGShmemHeader; /* avoid including pg_shmem.h */
27 extern void dsm_cleanup_using_control_segment(dsm_handle old_control_handle);
28 extern void dsm_postmaster_startup(struct PGShmemHeader *);
29 extern void dsm_backend_shutdown(void);
30 extern void dsm_detach_all(void);
31 
32 extern size_t dsm_estimate_size(void);
33 extern void dsm_shmem_init(void);
34 
35 #ifdef EXEC_BACKEND
36 extern void dsm_set_control_handle(dsm_handle h);
37 #endif
38 
39 /* Functions that create or remove mappings. */
40 extern dsm_segment *dsm_create(Size size, int flags);
42 extern void dsm_detach(dsm_segment *seg);
43 
44 /* Resource management functions. */
45 extern void dsm_pin_mapping(dsm_segment *seg);
46 extern void dsm_unpin_mapping(dsm_segment *seg);
47 extern void dsm_pin_segment(dsm_segment *seg);
48 extern void dsm_unpin_segment(dsm_handle h);
50 
51 /* Informational functions. */
52 extern void *dsm_segment_address(dsm_segment *seg);
55 
56 /* Cleanup hooks. */
58 extern void on_dsm_detach(dsm_segment *seg,
59  on_dsm_detach_callback function, Datum arg);
60 extern void cancel_on_dsm_detach(dsm_segment *seg,
61  on_dsm_detach_callback function, Datum arg);
62 extern void reset_on_dsm_detach(void);
63 
64 #endif /* DSM_H */
void dsm_detach_all(void)
Definition: dsm.c:741
void on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1091
void dsm_detach(dsm_segment *seg)
Definition: dsm.c:769
uint32 dsm_handle
Definition: dsm_impl.h:55
void dsm_pin_segment(dsm_segment *seg)
Definition: dsm.c:916
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:1054
void cancel_on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1106
void dsm_unpin_segment(dsm_handle h)
Definition: dsm.c:948
void dsm_unpin_mapping(dsm_segment *seg)
Definition: dsm.c:895
void dsm_shmem_init(void)
Definition: dsm.c:450
Size dsm_segment_map_length(dsm_segment *seg)
Definition: dsm.c:1064
dsm_segment * dsm_attach(dsm_handle h)
Definition: dsm.c:631
uintptr_t Datum
Definition: postgres.h:367
dsm_segment * dsm_find_mapping(dsm_handle h)
Definition: dsm.c:1035
void reset_on_dsm_detach(void)
Definition: dsm.c:1129
void dsm_pin_mapping(dsm_segment *seg)
Definition: dsm.c:876
void dsm_cleanup_using_control_segment(dsm_handle old_control_handle)
Definition: dsm.c:210
void dsm_postmaster_startup(struct PGShmemHeader *)
Definition: dsm.c:149
size_t Size
Definition: c.h:473
dsm_segment * dsm_create(Size size, int flags)
Definition: dsm.c:487
size_t dsm_estimate_size(void)
Definition: dsm.c:441
void * arg
void(* on_dsm_detach_callback)(dsm_segment *, Datum arg)
Definition: dsm.h:57
void dsm_backend_shutdown(void)
Definition: dsm.c:723
dsm_handle dsm_segment_handle(dsm_segment *seg)
Definition: dsm.c:1082