org/simgrid/msg/Sem.java

   1 /*\r
   2  * Simple semaphore implementation, from Doug Lea (public domain)\r
   3  *\r
   4  * Copyright 2006,2007,2010 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 \r
  15 /**\r
  16  *\r
  17  * @author lbobelin\r
  18  */\r
  19 public class Sem {\r
  20         /******************************************************************/ \r
  21         /* Simple semaphore implementation, from Doug Lea (public domain) */ \r
  22         /******************************************************************/ \r
  23         private int permits_;\r
  24 \r
  25     /**\r
  26      *\r
  27      * @param i\r
  28      */\r
  29     public Sem(int i) {\r
  30                 permits_ = i;\r
  31         } \r
  32 \r
  33     /**\r
  34      *\r
  35      * @throws java.lang.InterruptedException\r
  36      */\r
  37     public void acquire() throws InterruptedException {\r
  38                 if (Thread.interrupted())\r
  39                         throw new InterruptedException();\r
  40 \r
  41                 synchronized(this) {\r
  42                         try {\r
  43                                 while (permits_ <= 0)\r
  44                                         wait();\r
  45                                 --permits_;\r
  46                         }\r
  47                         catch(InterruptedException ex) {\r
  48                                 notify();\r
  49                                 throw ex;\r
  50                         }\r
  51                 }\r
  52         }\r
  53 \r
  54     /**\r
  55      *\r
  56      */\r
  57     public synchronized void release() {\r
  58                 ++(this.permits_);\r
  59                 notify();\r
  60         } \r
  61 } \r