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dsm_impl.h File Reference
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Macros

#define DSM_IMPL_POSIX   1
 
#define DSM_IMPL_SYSV   2
 
#define DSM_IMPL_WINDOWS   3
 
#define DSM_IMPL_MMAP   4
 
#define USE_DSM_SYSV
 
#define DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE   DSM_IMPL_SYSV
 
#define USE_DSM_MMAP
 
#define PG_DYNSHMEM_DIR   "pg_dynshmem"
 
#define PG_DYNSHMEM_MMAP_FILE_PREFIX   "mmap."
 

Typedefs

typedef uint32 dsm_handle
 

Enumerations

enum  dsm_op { DSM_OP_CREATE , DSM_OP_ATTACH , DSM_OP_DETACH , DSM_OP_DESTROY }
 

Functions

bool dsm_impl_op (dsm_op op, dsm_handle handle, Size request_size, void **impl_private, void **mapped_address, Size *mapped_size, int elevel)
 
void dsm_impl_pin_segment (dsm_handle handle, void *impl_private, void **impl_private_pm_handle)
 
void dsm_impl_unpin_segment (dsm_handle handle, void **impl_private)
 

Variables

PGDLLIMPORT int dynamic_shared_memory_type
 
PGDLLIMPORT int min_dynamic_shared_memory
 

Macro Definition Documentation

◆ DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE

#define DEFAULT_DYNAMIC_SHARED_MEMORY_TYPE   DSM_IMPL_SYSV

Definition at line 36 of file dsm_impl.h.

◆ DSM_IMPL_MMAP

#define DSM_IMPL_MMAP   4

Definition at line 20 of file dsm_impl.h.

◆ DSM_IMPL_POSIX

#define DSM_IMPL_POSIX   1

Definition at line 17 of file dsm_impl.h.

◆ DSM_IMPL_SYSV

#define DSM_IMPL_SYSV   2

Definition at line 18 of file dsm_impl.h.

◆ DSM_IMPL_WINDOWS

#define DSM_IMPL_WINDOWS   3

Definition at line 19 of file dsm_impl.h.

◆ PG_DYNSHMEM_DIR

#define PG_DYNSHMEM_DIR   "pg_dynshmem"

Definition at line 51 of file dsm_impl.h.

◆ PG_DYNSHMEM_MMAP_FILE_PREFIX

#define PG_DYNSHMEM_MMAP_FILE_PREFIX   "mmap."

Definition at line 52 of file dsm_impl.h.

◆ USE_DSM_MMAP

#define USE_DSM_MMAP

Definition at line 38 of file dsm_impl.h.

◆ USE_DSM_SYSV

#define USE_DSM_SYSV

Definition at line 34 of file dsm_impl.h.

Typedef Documentation

◆ dsm_handle

typedef uint32 dsm_handle

Definition at line 55 of file dsm_impl.h.

Enumeration Type Documentation

◆ dsm_op

enum dsm_op
Enumerator
DSM_OP_CREATE 
DSM_OP_ATTACH 
DSM_OP_DETACH 
DSM_OP_DESTROY 

Definition at line 58 of file dsm_impl.h.

59 {
64 } dsm_op;
dsm_op
Definition: dsm_impl.h:59
@ DSM_OP_DETACH
Definition: dsm_impl.h:62
@ DSM_OP_CREATE
Definition: dsm_impl.h:60
@ DSM_OP_DESTROY
Definition: dsm_impl.h:63
@ DSM_OP_ATTACH
Definition: dsm_impl.h:61

Function Documentation

◆ dsm_impl_op()

bool dsm_impl_op ( dsm_op  op,
dsm_handle  handle,
Size  request_size,
void **  impl_private,
void **  mapped_address,
Size mapped_size,
int  elevel 
)

Definition at line 161 of file dsm_impl.c.

164 {
165  Assert(op == DSM_OP_CREATE || request_size == 0);
166  Assert((op != DSM_OP_CREATE && op != DSM_OP_ATTACH) ||
167  (*mapped_address == NULL && *mapped_size == 0));
168 
170  {
171 #ifdef USE_DSM_POSIX
172  case DSM_IMPL_POSIX:
173  return dsm_impl_posix(op, handle, request_size, impl_private,
174  mapped_address, mapped_size, elevel);
175 #endif
176 #ifdef USE_DSM_SYSV
177  case DSM_IMPL_SYSV:
178  return dsm_impl_sysv(op, handle, request_size, impl_private,
179  mapped_address, mapped_size, elevel);
180 #endif
181 #ifdef USE_DSM_WINDOWS
182  case DSM_IMPL_WINDOWS:
183  return dsm_impl_windows(op, handle, request_size, impl_private,
184  mapped_address, mapped_size, elevel);
185 #endif
186 #ifdef USE_DSM_MMAP
187  case DSM_IMPL_MMAP:
188  return dsm_impl_mmap(op, handle, request_size, impl_private,
189  mapped_address, mapped_size, elevel);
190 #endif
191  default:
192  elog(ERROR, "unexpected dynamic shared memory type: %d",
194  return false;
195  }
196 }
int dynamic_shared_memory_type
Definition: dsm_impl.c:114
static bool dsm_impl_sysv(dsm_op op, dsm_handle handle, Size request_size, void **impl_private, void **mapped_address, Size *mapped_size, int elevel)
Definition: dsm_impl.c:415
static bool dsm_impl_mmap(dsm_op op, dsm_handle handle, Size request_size, void **impl_private, void **mapped_address, Size *mapped_size, int elevel)
Definition: dsm_impl.c:784
#define DSM_IMPL_WINDOWS
Definition: dsm_impl.h:19
#define DSM_IMPL_POSIX
Definition: dsm_impl.h:17
#define DSM_IMPL_SYSV
Definition: dsm_impl.h:18
#define DSM_IMPL_MMAP
Definition: dsm_impl.h:20
#define ERROR
Definition: elog.h:33
#define elog(elevel,...)
Definition: elog.h:218
Assert(fmt[strlen(fmt) - 1] !='\n')

References Assert(), dsm_impl_mmap(), DSM_IMPL_MMAP, DSM_IMPL_POSIX, dsm_impl_sysv(), DSM_IMPL_SYSV, DSM_IMPL_WINDOWS, DSM_OP_ATTACH, DSM_OP_CREATE, dynamic_shared_memory_type, elog, and ERROR.

Referenced by dsm_attach(), dsm_backend_startup(), dsm_cleanup_using_control_segment(), dsm_create(), dsm_detach(), dsm_detach_all(), dsm_postmaster_shutdown(), dsm_postmaster_startup(), and dsm_unpin_segment().

◆ dsm_impl_pin_segment()

void dsm_impl_pin_segment ( dsm_handle  handle,
void *  impl_private,
void **  impl_private_pm_handle 
)

Definition at line 955 of file dsm_impl.c.

957 {
959  {
960 #ifdef USE_DSM_WINDOWS
961  case DSM_IMPL_WINDOWS:
962  if (IsUnderPostmaster)
963  {
964  HANDLE hmap;
965 
966  if (!DuplicateHandle(GetCurrentProcess(), impl_private,
967  PostmasterHandle, &hmap, 0, FALSE,
968  DUPLICATE_SAME_ACCESS))
969  {
970  char name[64];
971 
972  snprintf(name, 64, "%s.%u", SEGMENT_NAME_PREFIX, handle);
973  _dosmaperr(GetLastError());
974  ereport(ERROR,
976  errmsg("could not duplicate handle for \"%s\": %m",
977  name)));
978  }
979 
980  /*
981  * Here, we remember the handle that we created in the
982  * postmaster process. This handle isn't actually usable in
983  * any process other than the postmaster, but that doesn't
984  * matter. We're just holding onto it so that, if the segment
985  * is unpinned, dsm_impl_unpin_segment can close it.
986  */
987  *impl_private_pm_handle = hmap;
988  }
989  break;
990 #endif
991  default:
992  break;
993  }
994 }
static int errcode_for_dynamic_shared_memory(void)
Definition: dsm_impl.c:1039
#define SEGMENT_NAME_PREFIX
Definition: dsm_impl.c:122
int errmsg(const char *fmt,...)
Definition: elog.c:904
#define ereport(elevel,...)
Definition: elog.h:143
const char * name
Definition: encode.c:561
bool IsUnderPostmaster
Definition: globals.c:113
#define snprintf
Definition: port.h:225
void _dosmaperr(unsigned long)
Definition: win32error.c:171

References _dosmaperr(), DSM_IMPL_WINDOWS, dynamic_shared_memory_type, ereport, errcode_for_dynamic_shared_memory(), errmsg(), ERROR, IsUnderPostmaster, name, SEGMENT_NAME_PREFIX, and snprintf.

Referenced by dsm_pin_segment().

◆ dsm_impl_unpin_segment()

void dsm_impl_unpin_segment ( dsm_handle  handle,
void **  impl_private 
)

Definition at line 1006 of file dsm_impl.c.

1007 {
1009  {
1010 #ifdef USE_DSM_WINDOWS
1011  case DSM_IMPL_WINDOWS:
1012  if (IsUnderPostmaster)
1013  {
1014  if (*impl_private &&
1015  !DuplicateHandle(PostmasterHandle, *impl_private,
1016  NULL, NULL, 0, FALSE,
1017  DUPLICATE_CLOSE_SOURCE))
1018  {
1019  char name[64];
1020 
1021  snprintf(name, 64, "%s.%u", SEGMENT_NAME_PREFIX, handle);
1022  _dosmaperr(GetLastError());
1023  ereport(ERROR,
1025  errmsg("could not duplicate handle for \"%s\": %m",
1026  name)));
1027  }
1028 
1029  *impl_private = NULL;
1030  }
1031  break;
1032 #endif
1033  default:
1034  break;
1035  }
1036 }

References _dosmaperr(), DSM_IMPL_WINDOWS, dynamic_shared_memory_type, ereport, errcode_for_dynamic_shared_memory(), errmsg(), ERROR, IsUnderPostmaster, name, SEGMENT_NAME_PREFIX, and snprintf.

Referenced by dsm_unpin_segment().

Variable Documentation

◆ dynamic_shared_memory_type

PGDLLIMPORT int dynamic_shared_memory_type
extern

◆ min_dynamic_shared_memory

PGDLLIMPORT int min_dynamic_shared_memory
extern

Definition at line 117 of file dsm_impl.c.

Referenced by dsm_estimate_size().