Editing Deadlock (computer science) (section)

===Detection===
Under the deadlock detection, deadlocks are allowed to occur. Then the state of the system is examined to detect that a deadlock has occurred and subsequently it is corrected. An algorithm is employed that tracks resource allocation and process states, it rolls back and restarts one or more of the processes in order to remove the detected deadlock. Detecting a deadlock that has already occurred is easily possible since the resources that each process has locked and/or currently requested are known to the [[Scheduler (computing)|resource scheduler]] of the operating system.<ref name=distri_tanen />

After a deadlock is detected, it can be corrected by using one of the following methods:{{Citation needed|date=May 2016}}
# ''Process termination:'' one or more processes involved in the deadlock may be aborted. One could choose to abort all competing [[Process (computing)|processes]] involved in the deadlock. This ensures that deadlock is resolved with certainty and speed.{{Citation needed|date=May 2016}} But the expense is high as partial computations will be lost. Or, one could choose to abort one process at a time until the deadlock is resolved. This approach has a high overhead because after each abort an algorithm must determine whether the system is still in deadlock.{{Citation needed|date=May 2016}} Several factors must be considered while choosing a candidate for termination, such as priority and age of the process.{{Citation needed|date=May 2016}}
# ''Resource preemption:'' resources allocated to various processes may be successively preempted and allocated to other processes until the deadlock is broken.<ref>{{cite web|url=https://www.ibm.com/support/knowledgecenter/SSETD4_9.1.2/lsf_admin/resource_preemption_about.html|title=IBM Knowledge Center|website=www.ibm.com|access-date=29 April 2018|url-status=live|archive-url=https://web.archive.org/web/20170319112925/https://www.ibm.com/support/knowledgecenter/SSETD4_9.1.2/lsf_admin/resource_preemption_about.html|archive-date=19 March 2017}}</ref>{{Failed verification|date=December 2021}}