Editing Reentrant mutex (section)

==Practical use==
[[W. Richard Stevens]] notes that recursive locks are "tricky" to use correctly, and recommends their use for adapting single-threaded code without changing [[Application programming interface|APIs]], but "only when no other solution is possible".<ref>{{cite book |title=Advanced Programming in the UNIX Environment |first1=W. Richard |last1=Stevens |first2=Stephen A. |last2=Rago |publisher=Addison-Wesley |year=2013 |page=434}}</ref>

The [[Java (programming language)|Java]] language's native synchronization mechanism, [[Monitor (synchronization)|monitor]], uses recursive locks. Syntactically, a lock is a block of code with the 'synchronized' keyword preceding it and any [[Object (computer science)|Object]] reference in parentheses that will be used as the mutex. Inside the synchronized block, the given object can be used as a condition variable by doing a wait(), notify(), or notifyAll() on it. Thus all Objects are both recursive mutexes and [[condition variable]]s.<ref>{{cite book |chapter-url=http://goose.ycp.edu/~dhovemey/spring2011/cs365/lecture/lecture17.html |title=CS 365 - Parallel and Distributed Computing |chapter=Lecture 17: Java Threads, Synchronization |author=David Hovemeyer|work=Lecture notes, [[York College of Pennsylvania]] |access-date=2015-06-04 }}</ref>