Editing Critical section (section)

=== Critical sections in data structures ===
In parallel programming, the code is divided into threads. The [[Read–write conflict|read-write conflicting]] variables are split between threads and each thread has a copy of them. Data structures such as [[linked list]]s, [[Tree (data structure)|trees]], and [[hash table]]s have data variables that are linked and cannot be split between threads; hence, implementing parallelism is very difficult.<ref name=":1">{{Cite book|title=Fundamentals of Parallel Multicore Architecture|last=Solihin|first=Yan|date=17 November 2015|publisher=Taylor & Francis |isbn=9781482211184}}</ref> To improve the efficiency of implementing data structures, multiple operations such as insertion, deletion, and search can be executed in parallel. While performing these operations, there may be scenarios where the same element is being searched by one thread and is being deleted by another. In such cases, the output may be [[Erroneous program|erroneous]]. The thread searching the element may have a hit, whereas the other thread may subsequently delete it. These scenarios will cause issues in the program running by providing false data. To prevent this, one method is to keep the entire data structure under critical section so that only one operation is handled at a time. Another method is locking the node in use under critical section, so that other operations do not use the same node. Using critical section, thus, ensures that the code provides expected outputs.<ref name=":1" />