H5O_DISABLE_MDC_FLUSHES

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

Procedure:

H5O_DISABLE_MDC_FLUSHES(object_id)

Signature:

herr_t H5Odisable_mdc_flushes( hid_t object_id )

Parameters:

hid_t object_id IN: Identifier of the object that will have flushes disabled; may be a group, named datatype, or dataset identifier

Description:

The H5O_ ENABLE/DISABLE_MDC_FLUSHES and associated H5X_FLUSH 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/H5O_FLUSH calls.

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

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 H5F_OPEN or H5F_CREATE) to this function.

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

Objects can be returned to the default automatic flush behavior with H5O_ENABLE_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.

Returns:

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

Example:

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History:

Release	Change
1.10.0	C function introduced with this release.

--- Last Modified: August 20, 2019 | 09:45 AM

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H5O_DISABLE_MDC_FLUSHES

Procedure:

Signature:

Parameters:

Description:

Returns:

Example:

History:

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