org/simgrid/msg/Sem.java

   1 /*\r
   2  * Simple semaphore implementation, from Doug Lea (public domain)\r
   3  *\r
   4  * Copyright 2006,2007,2010,2011 The SimGrid Team           \r
   5  * All right reserved. \r
   6  *\r
   7  * This program is free software; you can redistribute \r
   8  * it and/or modify it under the terms of the license \r
   9  *(GNU LGPL) which comes with this package. \r
  10  */  \r
  11 \r
  12 package org.simgrid.msg;\r
  13 \r
  14 public class Sem {\r
  15         /******************************************************************/ \r
  16         /* Simple semaphore implementation, from Doug Lea (public domain) */ \r
  17         /******************************************************************/ \r
  18         private int permits_;\r
  19 \r
  20     /**\r
  21      *\r
  22      * @param i\r
  23      */\r
  24     public Sem(int i) {\r
  25                 permits_ = i;\r
  26         } \r
  27 \r
  28     /**\r
  29      *\r
  30      * @throws java.lang.InterruptedException\r
  31      */\r
  32     public void acquire() throws InterruptedException {\r
  33                 if (Thread.interrupted())\r
  34                         throw new InterruptedException();\r
  35 \r
  36                 synchronized(this) {\r
  37                         try {\r
  38                                 while (permits_ <= 0)\r
  39                                         wait();\r
  40                                 --permits_;\r
  41                         }\r
  42                         catch(InterruptedException ex) {\r
  43                                 notify();\r
  44                                 throw ex;\r
  45                         }\r
  46                 }\r
  47         }\r
  48 \r
  49     /**\r
  50      *\r
  51      */\r
  52     public synchronized void release() {\r
  53                 ++(this.permits_);\r
  54                 notify();\r
  55         } \r
  56 } \r