pmem2_source_from_fd - Man Page

creates or deletes an instance 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 error code on failure.

The pmem2_source_delete() function always returns 0.

Errors

The pmem2_source_from_[fd|handle]() function can fail with the following errors:

On Linux:

On Windows:

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:

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 <http://pmem.io>

Referenced By

libpmem2(7), pmem2_map_from_existing(3), pmem2_map_new(3), pmem2_source_alignment(3), pmem2_source_get_handle(3).

The man pages pmem2_source_delete(3) and pmem2_source_from_handle(3) are aliases of pmem2_source_from_fd(3).

2020-10-28 PMDK - pmem2 API version 1.0 PMDK Programmer's Manual