1 files changed, 53 insertions, 0 deletions
diff --git a/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/prov/core/Locker_JavaIo.java b/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/prov/core/Locker_JavaIo.java
new file mode 100644
index 000000000..2ba6cf51d
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.core/src/org/eclipse/equinox/internal/prov/core/Locker_JavaIo.java
@@ -0,0 +1,53 @@
+/*******************************************************************************
+ * Copyright (c) 2004, 2007 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.equinox.internal.prov.core;
+
+import java.io.*;
+
+/**
+ * Internal class.
+ */
+public class Locker_JavaIo implements Locker {
+	private File lockFile;
+	private RandomAccessFile lockRAF;
+
+	public Locker_JavaIo(File lockFile) {
+		this.lockFile = lockFile;
+	}
+
+	public synchronized boolean lock() throws IOException {
+		//if the lock file already exists, try to delete,
+		//assume failure means another eclipse has it open
+		if (lockFile.exists())
+			lockFile.delete();
+		if (lockFile.exists())
+			return false;
+
+		//open the lock file so other instances can't co-exist
+		lockRAF = new RandomAccessFile(lockFile, "rw"); //$NON-NLS-1$
+		lockRAF.writeByte(0);
+
+		return true;
+	}
+
+	public synchronized void release() {
+		try {
+			if (lockRAF != null) {
+				lockRAF.close();
+				lockRAF = null;
+			}
+		} catch (IOException e) {
+			//don't complain, we're making a best effort to clean up
+		}
+		if (lockFile != null)
+			lockFile.delete();
+	}
+}