H5F_FLUSH causes all buffers associated with a file to be immediately flushed to disk without removing the data from the cache.
object_id can be any object associated with the file, including the file itself, a dataset, a group, an attribute, or a named datatype.
scope specifies whether the scope of the flushing action is global or local. Valid values are as follows:
|Flushes the entire virtual file|
|Flushes only the specified file|
HDF5 does not possess full control over buffering. H5F_FLUSH flushes the internal HDF5 buffers then asks the operating system (the OS) to flush the system buffers for the open files. After that, the OS is responsible for ensuring that the data is actually flushed to disk.