Microsoft Technology Licensing, LLC

Eric Ray Christensen

Hanumantha Rao Kodavalla

Robin Dhananjay Dhamankar

David G Campbell

Vishal Kathuria

Chunjia Li

Sethu M Kalavakur

David L Fulton

Gayathri Venkataraman

Avraham Levy

To ensure that logs representative of data changes are durably written, localized storage media cache is flushed to force a write to stable storage. Log sequence number tracking is leveraged to determine if log data in a localized storage media cache is likely to have not been written to durable storage. When this condition is likely, a FLUSH_CACHE command is issued to a storage media controller to force a durable write. This allows recovery of data changes to a transactional system even when its associated storage media does not provide write-ordering guarantees. Moreover, flushing of the storage media cache can be accomplished at a frequency that provides an upper bound on a maximum time between a transaction commit and data being made durable.

Enforced transaction system recoverability on media without write-through

A dynamic cache management mechanism determines the amount of memory available from a system on which a memory intensive application is running and dynamically manages the amount of cache for which real memory is associated or committed by the system. A background thread periodically queries the operating system to determine how much memory is available for use by applications. If the amount of memory, as identified in a free list is above a predetermined threshold, the application requests more memory for its use. If below the predetermined threshold, the application gives memory back to the operating system. The threshold used by the application to expand and shrink the memory it uses based upon system demand for memory.

Dynamic memory allocation based on free memory size

A technique for processing a critical code section which cannot be executed concurrently by more than one executable unit (e.g., a thread, a process, a fiber, etc.). A first executable unit prepares a packet containing a &ldquo;work request,&rdquo; which describes work to be performed by the critical section. If the critical section is not in use by a second executable unit, then the first executable unit enters the critical section and performs the work described in the packet. If the critical section is in use by a second executable unit, then the second executable unit performs the work described in the packet on behalf of the first executable unit, thereby alleviating the necessity for the first executable unit to enter the critical section. In addition to the work request, the packet may also contain: a status indicating whether the work request has been performed, an event to be signaled upon completion of the work request, and/or a list pointer that may be used to link packets together in a linked list.

Critical code processing management

A system and method for information retrieval includes an input device, a storage device, an output device, and a data file stored in the storage device including n data records, and one or more index files having data corresponding to a key value comprising information derived from a data record, and the record number of the data record containing the data from which the key value is derived. The retrieval system further includes memory for storing a temporary solution bitmask n bits in length where each bit corresponds to a record in the data file and logic for accessing the data file ascertaining the record number for each data record corresponding to a key value which satisfies the search criteria, and logic for setting the bit corresponding to that record number in the temporary solution bitmask. The system also preferably includes logic for analyzing individual search criteria in a search query containing a plurality of search criteria to determine the extent to which the search is optimizable using the present invention, and logic for combining each of the temporary solution bitmasks ascertained for particular search criteria in a query to obtain a final solution bitmask representative of the set of all data records satisfying the query.

Growing community of inventors

Redmond, WA, United States of America

Eric Ray Christensen