1 files changed, 24 insertions, 7 deletions

diff --git a/java/src/Mutex.java b/java/src/Mutex.java
index 8daab4ff9eb..1b796062ae8 100644
--- a/java/src/Mutex.java
+++ b/java/src/Mutex.java
@@ -61,13 +61,15 @@ public class Mutex
     {
       this.monitor_.timedWait ();
       this.monitor_.inUse (true);
+      setOwner();
     }
 
   /**
-   * Acquire the mutex. Note that the call will return if <timeout>
-   * amount of time expires.
-   *@param tv amount of time (TimeValue) to wait before returning
-   * (unless operation completes before)
+   * Acquire the mutex.
+   * Throws a TimeoutException if the mutex isn't acquired before the
+   * given absolute time timeout.
+   *@param tv time (TimeValue) to wait until before throwing a
+   * TimeoutException (unless the mutex is acquired before that)
    *@exception TimeoutException wait timed out exception
    *@exception InterruptedException exception during wait
    */
@@ -76,17 +78,32 @@ public class Mutex
     {
       this.monitor_.timedWait (tv);
       this.monitor_.inUse (true);
+      setOwner();
     }
 
   /**
-   * Release the mutex.
+   * Release the mutex.  This is safe for non-owners to call.
    */
   public synchronized void release ()
     {
-      this.monitor_.inUse (false);
-      this.monitor_.signal ();
+      if (isOwner()) {
+	  this.monitor_.inUse (false);
+	  this.monitor_.signal ();
+      }
     }
 
   private TimedWaitMAdapter monitor_ = new TimedWaitMAdapter (this);
   // The monitor (adapter) to wait on
+
+  // Keep track of the owner.  Allow subclasses to redefine this
+  // behavior
+  private Object owner_ = null;
+    
+  protected void setOwner() {
+      this.owner_ = Thread.currentThread().toString();
+  }
+
+  protected boolean isOwner() {
+      return Thread.currentThread().toString().equals(this.owner_);
+  }
 }