Editing Semaphore (programming) (section)

==Operation names==
The canonical names V and P come from the initials of [[Dutch language|Dutch]] words. V is generally explained as ''verhogen'' ("increase"). Several explanations have been offered for P, including ''proberen'' ("to test" or "to try"),<ref>{{citation |last1 = Silberschatz |first1 = Abraham | last2 = Galvin | first2 = Peter Baer | last3 = Gagne | first3 = Greg | edition = 8th | isbn = 978-0-470-12872-5 | publisher = John Wiley & Sons. Inc | title = Operating System Concepts | year = 2008 |page=234}}</ref> ''passeren'' ("pass"), and ''pakken'' ("grab"). Dijkstra's earliest paper on the subject<ref name="ReferenceA"/> gives ''passering'' ("passing") as the meaning for ''P'', and ''vrijgave'' ("release") as the meaning for V. It also mentions that the terminology is taken from that used in railroad signals. Dijkstra subsequently wrote that he intended ''P'' to stand for ''prolaag'',<ref>{{Cite EWD|74}}</ref> short for ''probeer te verlagen'', literally "try to reduce", or to parallel the terms used in the other case, "try to decrease".<ref>{{Cite EWD|51| MULTIPROGAMMERING EN DE X8}} (in [[Dutch language|Dutch]])</ref><ref name="try-and">Dijkstra's own translation reads "try-''and''-decrease", although that phrase might be confusing for those unaware of the [http://www.wsu.edu/~brians/errors/try.html colloquial "try-and..."]</ref><ref>[https://lkml.org/lkml/2005/12/19/34 (PATCH 1/19) MUTEX: Introduce simple mutex implementation] Linux Kernel Mailing List, 19 December 2005</ref>

In [[ALGOL 68]], the [[Linux kernel]],<ref>[http://www.linuxgrill.com/anonymous/fire/netfilter/kernel-hacking-HOWTO-5.html#ss5.3 Linux Kernel hacking HOWTO] {{Webarchive|url=https://web.archive.org/web/20100528154351/http://www.linuxgrill.com/anonymous/fire/netfilter/kernel-hacking-HOWTO-5.html#ss5.3 |date=2010-05-28 }} LinuxGrill.com</ref> and in some English textbooks, the ''V'' and ''P'' operations are called, respectively, ''up'' and ''down''. In software engineering practice, they are often called ''signal'' and ''wait'',<ref name="plan9">{{cite conference |last1=Mullender |first1=Sape |first2=Russ |last2=Cox |title=Semaphores in Plan 9 |conference=3rd International Workshop on [[Plan 9 from Bell Labs|Plan 9]] |year=2008 |url=http://doc.cat-v.org/plan_9/IWP9/2008/iwp9_proceedings08.pdf#page=62}}</ref> ''release'' and ''acquire''{{r|plan9}} (standard [[Java (programming language)|Java]] library),<ref>{{Javadoc:SE|package=java.util.concurrent|java/util/concurrent|Semaphore}}</ref> or ''post'' and ''pend''. Some texts call them ''vacate'' and ''procure'' to match the original Dutch initials.<ref>{{Cite web|url=http://amigadev.elowar.com/read/ADCD_2.1/Includes_and_Autodocs_2._guide/node036A.html|title=exec.library/Procure|website=amigadev.elowar.com|access-date=2016-09-19}}</ref><ref>{{Cite web|url=http://amigadev.elowar.com/read/ADCD_2.1/Includes_and_Autodocs_2._guide/node0389.html|title=exec.library/Vacate|website=amigadev.elowar.com|access-date=2016-09-19}}</ref>