From 79d72b6292858b957d706171939136e627b29773 Mon Sep 17 00:00:00 2001
From: curt <curt>
Date: Sat, 28 Feb 2004 18:51:20 +0000
Subject: [PATCH] Add front() methods SGQueue, SGLockedQueue, and
 SGBlockingQueue so that the can be used more interchangably with a regular
 STL queue.

---
 simgear/threads/SGQueue.hxx | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/simgear/threads/SGQueue.hxx b/simgear/threads/SGQueue.hxx
index 25fa2ca5..9d4dcf31 100644
--- a/simgear/threads/SGQueue.hxx
+++ b/simgear/threads/SGQueue.hxx
@@ -47,6 +47,13 @@ public:
      */
     virtual void push( const T& item ) = 0;
 
+    /**
+     * View the item from the head of the queue.
+     *
+     * @return T next available object.
+     */
+    virtual T front() = 0;
+
     /**
      * Get an item from the head of the queue.
      *
@@ -99,6 +106,18 @@ public:
 	fifo.push( item );
     }
 
+    /**
+     * View the item from the head of the queue.
+     *
+     * @return T next available object.
+     */
+    virtual T front() {
+	SGGuard<SGLOCK> g(mutex);
+	assert( ! fifo.empty() );
+	T item = fifo.front();
+	return item;
+    }
+
     /**
      * Get an item from the head of the queue.
      *
@@ -167,6 +186,22 @@ public:
 	not_empty.signal();
     }
 
+    /**
+     * View the item from the head of the queue.
+     * Calling thread is not suspended
+     *
+     * @return T next available object.
+     */
+    virtual T front() {
+	SGGuard<SGMutex> g(mutex);
+
+	assert(fifo.empty() != true);
+	//if (fifo.empty()) throw ??
+
+	T item = fifo.front();
+	return item;
+    }
+
     /**
      * Get an item from the head of the queue.
      * If no items are available then the calling thread is suspended
-- 
2.39.5