added a test for Mutex properties of the locking system

src/main/java/JobServ/ProcessController.java

@@ -124,12 +124,12 @@ class ProcessController {
         try {
             this.input.close();
             this.output.close();
+            this.outputScanner.close();
+            this.process.destroy();
         } catch (IOException e) {
             // streams already closed
         }
 
-        process.destroy();
-
         this.killedManually = true;
     }
 }

src/main/java/JobServ/ProcessManager.java

@@ -225,10 +225,11 @@ class ProcessManager {
     /*
      * getLock()
      * Locks access to this.processQueue
-     * Waits for a predefined timeout period and then grabs the mutex
+     * Waits for a predefined timeout period for mutex to be avail.
+     * Synchronized so two things cannot grab lock at once.
      * Throws TimeoutException when it fails to get the lock.
      */
-    private void getLock() throws TimeoutException {
+    protected synchronized void getLock() throws TimeoutException {
         Future<Object> future = this.threadPool.submit(this.lockCallable);
 
         try {
@@ -266,7 +267,7 @@ class ProcessManager {
      * releaseLock()
      * releases mutex so other threads can operate on processqueue
      */
-    private void releaseLock() {
+    protected void releaseLock() {
         this.processQueueMutex = false;
     }