14.java5 's Semaphere Sync Tool

1 ImportJava.util.concurrent.ExecutorService;2 Importjava.util.concurrent.Executors;3 ImportJava.util.concurrent.Semaphore;4 5 /**6 * 14.JAVA5 's semaphere sync tool7 * Semaphore can maintain the number of threads currently accessing itself and provides a synchronization mechanism. 8 * Use semaphore to control the number of threads concurrently accessing resources, for example, to implement a9 * The number of concurrent accesses allowed by the file. Ten * The semaphore object of a single semaphore can implement the mutex function, and it can be One * One thread obtains a "lock" and another thread releases "lock", which can be applied to some occasions of deadlock recovery.  A  * @authorlitaiqing -  * -  */ the  Public classSemaphoretest { -      Public Static voidMain (string[] args) { -Executorservice Service =Executors.newcachedthreadpool (); -         FinalSemaphore SP =NewSemaphore (3); +          for(inti = 0; I < 10; i++) { -Runnable Runnable =NewRunnable () { +                  Public voidrun () { A                     Try { at Sp.acquire (); -}Catch(interruptedexception E1) { - e1.printstacktrace (); -                     } -SYSTEM.OUT.PRINTLN ("Thread" +Thread.CurrentThread (). GetName () -+ "Enter, current already" + (3-sp.availablepermits ()) + "concurrency"); in                     Try { -Thread.Sleep ((Long) (Math.random () * 10000)); to}Catch(interruptedexception e) { + e.printstacktrace (); -                     } theSYSTEM.OUT.PRINTLN ("Thread" +Thread.CurrentThread (). GetName () *+ "Leaving soon"); $ sp.release ();Panax Notoginseng                     //The following code is sometimes executed inaccurately because it does not synthesize atomic units with the above code -SYSTEM.OUT.PRINTLN ("Thread" +Thread.CurrentThread (). GetName () the+ "has left, currently has" + (3-sp.availablepermits ()) + "concurrency"); +                 } A             }; the Service.execute (runnable); +         } -     } $}

14.java5 's Semaphere Sync Tool