Editing Double-ended queue (section)

== Applications ==
[[File:Back button history (Ecosia browser - Google Pixel 4a) - Google Android 12 (cropped).png|thumb|A double-ended queue can be used to store the [[Web browsing history|browsing history]]: new websites are added to the end of the queue, while the oldest entries will be deleted when the history is too large. When a user asks to clear the browsing history for the past hour, the most recently added entries are removed.]]
One example where a deque can be used is the [[Work stealing|work stealing algorithm]].<ref name="jacm">{{cite journal |last1=Blumofe |first1=Robert D. |first2=Charles E. |last2=Leiserson |author-link2=Charles E. Leiserson |title=Scheduling multithreaded computations by work stealing |journal=J ACM |volume=46 |issue=5 |year=1999 |pages=720–748 |url=http://supertech.csail.mit.edu/papers/ft_gateway.pdf |doi=10.1145/324133.324234|s2cid=5428476 }}</ref> This algorithm implements task scheduling for several processors. A separate deque with threads to be executed is maintained for each processor. To execute the next thread, the processor gets the first element from the deque (using the "remove first element" deque operation). If the current thread forks, it is put back to the front of the deque ("insert element at front") and a new thread is executed. When one of the processors finishes execution of its own threads (i.e. its deque is empty), it can "steal" a thread from another processor: it gets the last element from the deque of another processor ("remove last element") and executes it. The work stealing algorithm is used by Intel's Threading Building Blocks (TBB) library for parallel programming.