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Diffstat (limited to '')
-rw-r--r-- | src/include/storage/dsm.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/include/storage/dsm.h b/src/include/storage/dsm.h new file mode 100644 index 0000000..408c054 --- /dev/null +++ b/src/include/storage/dsm.h @@ -0,0 +1,61 @@ +/*------------------------------------------------------------------------- + * + * dsm.h + * manage dynamic shared memory segments + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/storage/dsm.h + * + *------------------------------------------------------------------------- + */ +#ifndef DSM_H +#define DSM_H + +#include "storage/dsm_impl.h" + +typedef struct dsm_segment dsm_segment; + +#define DSM_CREATE_NULL_IF_MAXSEGMENTS 0x0001 + +/* A sentinel value for an invalid DSM handle. */ +#define DSM_HANDLE_INVALID 0 + +/* Startup and shutdown functions. */ +struct PGShmemHeader; /* avoid including pg_shmem.h */ +extern void dsm_cleanup_using_control_segment(dsm_handle old_control_handle); +extern void dsm_postmaster_startup(struct PGShmemHeader *); +extern void dsm_backend_shutdown(void); +extern void dsm_detach_all(void); + +#ifdef EXEC_BACKEND +extern void dsm_set_control_handle(dsm_handle h); +#endif + +/* Functions that create or remove mappings. */ +extern dsm_segment *dsm_create(Size size, int flags); +extern dsm_segment *dsm_attach(dsm_handle h); +extern void dsm_detach(dsm_segment *seg); + +/* Resource management functions. */ +extern void dsm_pin_mapping(dsm_segment *seg); +extern void dsm_unpin_mapping(dsm_segment *seg); +extern void dsm_pin_segment(dsm_segment *seg); +extern void dsm_unpin_segment(dsm_handle h); +extern dsm_segment *dsm_find_mapping(dsm_handle h); + +/* Informational functions. */ +extern void *dsm_segment_address(dsm_segment *seg); +extern Size dsm_segment_map_length(dsm_segment *seg); +extern dsm_handle dsm_segment_handle(dsm_segment *seg); + +/* Cleanup hooks. */ +typedef void (*on_dsm_detach_callback) (dsm_segment *, Datum arg); +extern void on_dsm_detach(dsm_segment *seg, + on_dsm_detach_callback function, Datum arg); +extern void cancel_on_dsm_detach(dsm_segment *seg, + on_dsm_detach_callback function, Datum arg); +extern void reset_on_dsm_detach(void); + +#endif /* DSM_H */ |