+/*
+ * Copyright 2012 The SimGrid team. All right reserved.
+ *
+ * This program is free software; you can redistribute
+ * it and/or modify it under the terms of the license
+ * (GNU LGPL) which comes with this package.
+ *
+ */
+package org.simgrid.msg;
+/** A semaphore implemented on top of SimGrid synchronization mechanisms.
+ * You can use it exactly the same way that you use classical semaphores
+ * but to handle the interactions between the processes within the simulation.
+ *
+ */
+
+public class Semaphore {
+ private long bind; // The C object -- don't touch it
+ /**
+ * Semaphore capacity, defined when the semaphore is created. At most capacity
+ * process can acquire this semaphore at the same time.
+ */
+ protected final int capacity;
+ /**
+ * Creates a new semaphore with the given capacity. At most capacity
+ * process can acquire this semaphore at the same time.
+ */
+ public Semaphore(int capacity) {
+ init(capacity);
+ this.capacity = capacity;
+ }
+ /** The native implementation of semaphore initialization
+ */
+ private native void init(int capacity);
+
+
+ /** Locks on the semaphore object until the provided timeout expires
+ * @exception TimeoutException if the timeout expired before
+ * the semaphore could be acquired.
+ */
+ public native void acquire(double timeout) throws TimeoutException;
+ /** Locks on the semaphore object with no timeout
+ */
+ public void acquire() {
+ try {
+ acquire(-1);
+ } catch (TimeoutException e) {
+ // This should not happen.
+ assert(false);
+ }
+ }
+ /** Releases the semaphore object
+ */
+ public native void release();
+ /** returns a boolean indicating it this semaphore would block at this very specific time
+ *
+ * Note that the returned value may be wrong right after the
+ * function call, when you try to use it... But that's a
+ * classical semaphore issue, and SimGrid's semaphores are not
+ * different to usual ones here.
+ */
+ public native boolean wouldBlock();
+
+ /** Returns the semaphore capacity
+ */
+ public int getCapacity(){
+ return this.capacity;
+ }
+
+
+ /** Deletes this semaphore
+ */
+ protected void finalize() {
+ destroy();
+ }
+ /** The native implementation for destroying a semaphore
+ */
+ private native void destroy();
+ /**
+ * Class initializer, to initialize various JNI stuff
+ */
+ public static native void nativeInit();
+ static {
+ Msg.nativeInit();
+ nativeInit();
+ }
+}
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