NAME

       pmem2_source_from_fd(),  pmem2_source_from_handle(),  pmem2_source_delete()  -  creates or deletes an in‐
       stance of persistent memory data source

SYNOPSIS

              #include <libpmem2.h>

              int pmem2_source_from_fd(struct pmem2_source *src, int fd);
              int pmem2_source_from_handle(struct pmem2_source *src, HANDLE handle); /* Windows only */
              int pmem2_source_delete(struct pmem2_source **src);

DESCRIPTION

       On Linux the pmem2_source_from_fd() function validates the file descriptor and instantiates a new *struct
       pmem2_source** object describing the data source.

       On Windows the pmem2_source_from_fd() function converts  a  file  descriptor  to  a  file  handle  (using
       **_get_osfhandle()),  and  passes  it  to  pmem2_source_from_handle().  By default _get_osfhandle() calls
       abort() in case of invalid file descriptor, but this behavior can be suppressed by  _set_abort_behavior()
       and  SetErrorMode**()  functions.  Please check MSDN documentation for more information about Windows CRT
       error handling.

       fd must be opened with O_RDONLY or O_RDWR mode, but on Windows it is not validated.

       If fd is invalid, then the function fails.

       The pmem2_source_from_handle() function validates the handle and instantiates a new *struct  pmem2_source
       object describing the data source. If handle is INVALID_HANDLE_VALUE, then the function fails. The handle
       has  to  be  created  with  an access mode of GENERIC_READ or (GENERIC_READ | GENERIC_WRITE). For details
       please see the CreateFile**() documentation.

       The   pmem2_source_delete()   function    frees    *src    returned    by    pmem2_source_from_fd()    or
       pmem2_source_from_handle() and sets *src to NULL.  If *src is NULL, no operation is performed.

RETURN VALUE

       The pmem2_source_from_fd() and pmem2_source_from_handle() functions return 0 on success or a negative er‐
       ror code on failure.

       The pmem2_source_delete() function always returns 0.

ERRORS

       The pmem2_source_from_fd()/pmem2_source_from_handle() functions can fail with the following errors:

       • PMEM2_E_INVALID_FILE_HANDLE - fd is not an open and valid file descriptor.  On Windows the function can
         abort() on this failure based on CRT’s abort() behavior.

       • PMEM2_E_INVALID_FILE_HANDLE - fd is opened in O_WRONLY mode.

       On Linux:

       • PMEM2_E_INVALID_FILE_TYPE - fd points to a directory, block device, pipe, or socket.

       • PMEM2_E_INVALID_FILE_TYPE - fd points to a character device other than Device DAX.

       On Windows:

       • PMEM2_E_INVALID_FILE_TYPE - handle points to a resource that is not a regular file.

       On  Windows  pmem2_source_from_fd()  can return all errors from the underlying pmem2_source_from_handle()
       function.

       The pmem2_source_from_handle() can return the following errors:

       • PMEM2_E_INVALID_FILE_HANDLE - handle points to a resource that is not a file.

       • PMEM2_E_INVALID_FILE_TYPE - handle points to a directory.

       The pmem2_source_from_fd() and pmem2_source_from_handle() functions can also return -ENOMEM  in  case  of
       insufficient memory to allocate an instance of struct pmem2_source.

CAVEATS

       On non-DAX Windows volumes, fd/handle must remain open while the mapping is in use.

SEE ALSO

       errno(3), pmem2_map_new(3), libpmem2(7) and <https://pmem.io>