Search results
Results from the WOW.Com Content Network
The lost update problem: A second transaction writes a second value of a data-item (datum) on top of a first value written by a first concurrent transaction, and the first value is lost to other transactions running concurrently which need, by their precedence, to read the first value. The transactions that have read the wrong value end with ...
Research [1] and literature [2] on concurrency testing and concurrent testing typically focuses on testing software and systems that use concurrent computing.The purpose is, as with most software testing, to understand the behaviour and performance of a software system that uses concurrent computing, particularly assessing the stability of a system or application during normal activity.
Optimistic concurrency control (OCC), also known as optimistic locking, is a non-locking concurrency control method applied to transactional systems such as relational database management systems and software transactional memory.
Common exceptions include an invalid argument (e.g. value is outside of the domain of a function), [5] an unavailable resource (like a missing file, [6] a network drive error, [7] or out-of-memory errors [8]), or that the routine has detected a normal condition that requires special handling, e.g., attention, end of file. [9]
This ensures correct release even if there is a return within the body or an exception thrown. Further, note that the acquisition occurs before the try clause, ensuring that the finally clause is only executed if the open code succeeds (without throwing an exception), assuming that "no exception" means "success" (as is the case for open in Python).
For unordered access as defined in the java.util.Map interface, the java.util.concurrent.ConcurrentHashMap implements java.util.concurrent.ConcurrentMap. [2] The mechanism is a hash access to a hash table with lists of entries, each entry holding a key, a value, the hash, and a next reference.
Reconciliation of concurrent writes must occur sometime before the next read, and can be scheduled at different instants: [3] [12] Read repair: The correction is done when a read finds an inconsistency. This slows down the read operation. Write repair: The correction takes place during a write operation, slowing down the write operation.
On 19 July at 04:09 UTC, CrowdStrike distributed a faulty configuration update for its Falcon sensor software running on Windows PCs and servers. A modification to a configuration file which was responsible for screening named pipes, Channel File 291, caused an out-of-bounds memory read [14] in the Windows sensor client that resulted in an invalid page fault.