dsm_impl.h File Reference

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

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."
#define	DSM_HANDLE_INVALID   ((dsm_handle) 0)

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_HANDLE_INVALID

#define DSM_HANDLE_INVALID   ((dsm_handle) 0)

Definition at line 58 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 61 of file dsm_impl.h.

{
    DSM_OP_CREATE,
    DSM_OP_ATTACH,
    DSM_OP_DETACH,
    DSM_OP_DESTROY,
} dsm_op;

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  )

extern

Definition at line 160 of file dsm_impl.c.

{
    Assert(op == DSM_OP_CREATE || request_size == 0);
    Assert((op != DSM_OP_CREATE && op != DSM_OP_ATTACH) ||
           (*mapped_address == NULL && *mapped_size == 0));
 
    switch (dynamic_shared_memory_type)
    {
#ifdef USE_DSM_POSIX
        case DSM_IMPL_POSIX:
            return dsm_impl_posix(op, handle, request_size, impl_private,
                                  mapped_address, mapped_size, elevel);
#endif
#ifdef USE_DSM_SYSV
        case DSM_IMPL_SYSV:
            return dsm_impl_sysv(op, handle, request_size, impl_private,
                                 mapped_address, mapped_size, elevel);
#endif
#ifdef USE_DSM_WINDOWS
        case DSM_IMPL_WINDOWS:
            return dsm_impl_windows(op, handle, request_size, impl_private,
                                    mapped_address, mapped_size, elevel);
#endif
#ifdef USE_DSM_MMAP
        case DSM_IMPL_MMAP:
            return dsm_impl_mmap(op, handle, request_size, impl_private,
                                 mapped_address, mapped_size, elevel);
#endif
        default:
            elog(ERROR, "unexpected dynamic shared memory type: %d",
                 dynamic_shared_memory_type);
            return false;
    }
}

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

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  )

extern

Definition at line 964 of file dsm_impl.c.

{
    switch (dynamic_shared_memory_type)
    {
#ifdef USE_DSM_WINDOWS
        case DSM_IMPL_WINDOWS:
            if (IsUnderPostmaster)
            {
                HANDLE      hmap;
 
                if (!DuplicateHandle(GetCurrentProcess(), impl_private,
                                     PostmasterHandle, &hmap, 0, FALSE,
                                     DUPLICATE_SAME_ACCESS))
                {
                    char        name[64];
 
                    snprintf(name, 64, "%s.%u", SEGMENT_NAME_PREFIX, handle);
                    _dosmaperr(GetLastError());
                    ereport(ERROR,
                            (errcode_for_dynamic_shared_memory(),
                             errmsg("could not duplicate handle for \"%s\": %m",
                                    name)));
                }
 
                /*
                 * Here, we remember the handle that we created in the
                 * postmaster process.  This handle isn't actually usable in
                 * any process other than the postmaster, but that doesn't
                 * matter.  We're just holding onto it so that, if the segment
                 * is unpinned, dsm_impl_unpin_segment can close it.
                 */
                *impl_private_pm_handle = hmap;
            }
            break;
#endif
        default:
            break;
    }
}

References _dosmaperr(), DSM_IMPL_WINDOWS, dynamic_shared_memory_type, ereport, errcode_for_dynamic_shared_memory(), errmsg, ERROR, fb(), 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  )

extern

Definition at line 1015 of file dsm_impl.c.

{
    switch (dynamic_shared_memory_type)
    {
#ifdef USE_DSM_WINDOWS
        case DSM_IMPL_WINDOWS:
            if (IsUnderPostmaster)
            {
                if (*impl_private &&
                    !DuplicateHandle(PostmasterHandle, *impl_private,
                                     NULL, NULL, 0, FALSE,
                                     DUPLICATE_CLOSE_SOURCE))
                {
                    char        name[64];
 
                    snprintf(name, 64, "%s.%u", SEGMENT_NAME_PREFIX, handle);
                    _dosmaperr(GetLastError());
                    ereport(ERROR,
                            (errcode_for_dynamic_shared_memory(),
                             errmsg("could not duplicate handle for \"%s\": %m",
                                    name)));
                }
 
                *impl_private = NULL;
            }
            break;
#endif
        default:
            break;
    }
}

References _dosmaperr(), DSM_IMPL_WINDOWS, dynamic_shared_memory_type, ereport, errcode_for_dynamic_shared_memory(), errmsg, ERROR, fb(), 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

Definition at line 113 of file dsm_impl.c.

Referenced by dsm_impl_op(), dsm_impl_pin_segment(), dsm_impl_unpin_segment(), and dsm_postmaster_startup().

min_dynamic_shared_memory

PGDLLIMPORT int min_dynamic_shared_memory

extern

Definition at line 116 of file dsm_impl.c.

Referenced by dsm_estimate_size().