oracular (3) pmem2_map_from_existing.3.gz

NAME

       pmem2_map_from_existing() - creates a pmem2_map object from an existing mapping

SYNOPSIS

              #include <libpmem2.h>

              int pmem2_map_from_existing(struct pmem2_map **map, const struct pmem2_source *src,
                  void *addr, size_t len, enum pmem2_granularity gran);

DESCRIPTION

       The  pmem2_map_from_existing()  returns  a  new  *struct pmem2_map for mapping provided by the user. This
       function allows usage of libpmem2(7) API without pmem2_map_new(3) for mapping file. Mapping is defined by
       addr  and  len. You have to specify underlying file as a src, and define granularity of this mapping. See
       pmem2_config_set_required_store_granularity(3) and libpmem2**(7) for more details.

       For the pmem2_map object created by the pmem2_map_from_existing(3) function, the pmem2_map_delete(3) will
       only destroy the object, but it won’t unmap the mapping this object describes.

RETURN VALUE

       The pmem2_map_from_existing() function returns 0 when it succeeds or a negative error code on failure.

ERRORS

       The pmem2_map_from_existing() can fail with the following errors:

       PMEM2_E_MAPPING_EXISTS - when contiguous region (addr, addr + len) is already registered by libpmem2

       It can also return -ENOMEM from the underlying malloc(2) function.

SEE ALSO

       malloc(2),    pmem2_map_delete(3),    pmem2_map_new(3),    pmem2_source_from_fd(3),    libpmem2(7)    and
       <https://pmem.io>