From b32248cf458a04ffe3cfcf0242e2edc6e28461a8 Mon Sep 17 00:00:00 2001
From: Jon Bratseth <bratseth@yahoo-inc.com>
Date: Wed, 28 Jun 2017 13:23:46 +0200
Subject: Move CuratorMutex to make it reusable

---
 .../java/com/yahoo/vespa/curator/CuratorMutex.java | 53 ++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 zkfacade/src/main/java/com/yahoo/vespa/curator/CuratorMutex.java

(limited to 'zkfacade/src/main/java')

diff --git a/zkfacade/src/main/java/com/yahoo/vespa/curator/CuratorMutex.java b/zkfacade/src/main/java/com/yahoo/vespa/curator/CuratorMutex.java
new file mode 100644
index 00000000000..e3dee56fcd6
--- /dev/null
+++ b/zkfacade/src/main/java/com/yahoo/vespa/curator/CuratorMutex.java
@@ -0,0 +1,53 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.curator;
+
+import com.google.common.util.concurrent.UncheckedTimeoutException;
+import com.yahoo.transaction.Mutex;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.recipes.locks.InterProcessMutex;
+
+import java.time.Duration;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A cluster-wide reentrant mutex which is released on (the last symmetric) close
+ *
+ * @author bratseth
+ */
+public class CuratorMutex implements Mutex {
+
+    private final InterProcessMutex mutex;
+    private final String lockPath;
+
+    public CuratorMutex(String lockPath, CuratorFramework curator) {
+        this.lockPath = lockPath;
+        mutex = new InterProcessMutex(curator, lockPath);
+    }
+
+    /** Take the lock with the given timeout. This may be called multiple times from the same thread - each matched by a close */
+    public void acquire(Duration timeout) {
+        boolean acquired;
+        try {
+            acquired = mutex.acquire(timeout.toMillis(), TimeUnit.MILLISECONDS);
+        }
+        catch (Exception e) {
+            throw new RuntimeException("Exception acquiring lock '" + lockPath + "'", e);
+        }
+
+        if (! acquired) throw new UncheckedTimeoutException("Timed out after waiting " + timeout.toString() +
+                                                            " to acquire lock + '" + lockPath + "'");
+    }
+
+    @Override
+    public void close() {
+        try {
+            mutex.release();
+        }
+        catch (Exception e) {
+            throw new RuntimeException("Exception releasing lock '" + lockPath + "'");
+        }
+    }
+
+}
+
+
-- 
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