From 645bc92d994dfb44806cb03aedd18452dd0bbc76 Mon Sep 17 00:00:00 2001
From: Jim Blake <jeb228@cornell.edu>
Date: Fri, 24 Oct 2014 10:28:43 -0400
Subject: [PATCH] A bit of syntactic sugar for critical sections.

---
 .../vitro/webapp/utils/jena/Critical.java     | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 webapp/src/edu/cornell/mannlib/vitro/webapp/utils/jena/Critical.java

diff --git a/webapp/src/edu/cornell/mannlib/vitro/webapp/utils/jena/Critical.java b/webapp/src/edu/cornell/mannlib/vitro/webapp/utils/jena/Critical.java
new file mode 100644
index 000000000..113645909
--- /dev/null
+++ b/webapp/src/edu/cornell/mannlib/vitro/webapp/utils/jena/Critical.java
@@ -0,0 +1,39 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+
+package edu.cornell.mannlib.vitro.webapp.utils.jena;
+
+import static com.hp.hpl.jena.shared.Lock.READ;
+import static com.hp.hpl.jena.shared.Lock.WRITE;
+
+import com.hp.hpl.jena.rdf.model.Model;
+
+/**
+ * Use this in a try-with-resources block.
+ * 
+ * <pre>
+ * try (Critical section = Critical.read(model)) {
+ * }
+ * </pre>
+ */
+public class Critical implements AutoCloseable {
+	public static Critical read(Model model) {
+		return new Critical(model, READ);
+	}
+
+	public static Critical write(Model model) {
+		return new Critical(model, WRITE);
+	}
+	
+	private final Model model;
+
+	private Critical(Model model, boolean readLockRequested) {
+		this.model = model;
+		this.model.enterCriticalSection(readLockRequested);
+	}
+
+	@Override
+	public void close() {
+		this.model.leaveCriticalSection();
+	}
+
+}