Gets Harvey's changes

1 files changed, 85 insertions, 0 deletions

diff --git a/src/javax/media/j3d/GeometryLock.java b/src/javax/media/j3d/GeometryLock.java
new file mode 100644
index 0000000..bb1132c
--- /dev/null
+++ b/src/javax/media/j3d/GeometryLock.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright 1999-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package javax.media.j3d;
+
+
+class GeometryLock {
+
+    // Current thread holding the lock
+    Thread threadId = null;
+
+    // Whether the lock is currently owned
+    boolean lockOwned = false;
+
+    // Count > 1 , if there is nested lock by the same thread
+    int count = 0;
+
+    // Number of outstanding threads waiting for the lock
+    int waiting = 0;
+
+
+    synchronized void getLock() {
+	Thread curThread = Thread.currentThread();
+	// If the thread already has the lock, incr
+	// a count and return
+	if (threadId == curThread) {
+	    count++;
+	    return;
+	}
+	// Otherwise, wait until the lock is released
+	while (lockOwned) {
+	    try {
+		waiting++;
+		wait();
+	    } catch (InterruptedException e) {
+		System.err.println(e);
+	    }
+	    waiting--;
+	}
+	count++;
+	// Acquire the lock
+	lockOwned = true;
+	threadId = curThread;
+    }
+
+    synchronized void unLock() {
+	Thread curThread = Thread.currentThread();
+	if (threadId == curThread) {
+	    // If the lock count > 0, then return
+	    if (--count > 0) {
+		return;
+	    }
+	    lockOwned = false;
+	    threadId = null;
+	    if (waiting > 0) {
+		notify();
+	    }
+	}
+
+    }
+
+}