Last modified: 28 January 2016

Name: H5Odisable_mdc_flushes

Signature:
herr_t H5Odisable_mdc_flushes( hid_t object_id )

Purpose:
Prevents metadata entries for an HDF5 object from being flushed from the metadata cache to storage.

Description:
The H5O/H5Fenable/disable_mdc_flushes() and associated H5Xflush() functions can be used to control the flushing of entries from a file’s metadata cache.

This function prevents an object’s or cache’s dirty metadata entries from being flushed from the cache by the usual cache eviction/flush policy. Instead, users must manually flush the cache or entries for individual objects via the appropriate H5F/H5D/H5G/H5T/H5Oflush() calls.

Metadata cache entries can be controlled at both the individual HDF5 object level (datasets, groups, committed datatypes) and the entire metadata cache level.


Note:
HDF5 objects include datasets, groups, and committed datatypes. Only hid_t identifiers that represent these objects can be passed to this function.

Passing in a hid_t identifier that represents any other HDF5 entity is considered an error.

It is an error to pass an HDF5 file identifier (obtained from H5Fopen() or H5Fcreate()) to this function. Use H5Fdisable_mdc_flushes instead.

Misuse of this function can cause the cache to exhaust available memory.

Objects can be returned to the default automatic flush behavior with H5Oenable_mdc_flushes().

Flush prevention only pertains to new or dirty metadata entries. Clean entries can be evicted from the cache.

Calling this function on an object that has already had flushes disabled will return an error.


Parameters:
hid_t object_id    IN: Identifier of the object that will have flushes disabled.
See the above notes for restrictions.

Returns:
Returns a non-negative value if successful; otherwise returns a negative value.

Fortran Interface:
None

See Also:



History:
Release     Change
1.10.0 C function introduced with this release.