Added auto_mutex::unlock()

dlib/threads/auto_mutex_extension.h

@@ -63,15 +63,29 @@ namespace dlib
             rw->lock();
         }
 
-        ~auto_mutex (
-        )
+        void unlock()
         {
             if (m != 0)
+            {
                 m->unlock();
+                m = 0;
+            }
             else if (r != 0)
+            {
                 r->unlock();
-            else
+                r = 0;
+            }
+            else if (rw != 0)
+            {
                 rw->unlock();
+                rw = 0;
+            }
+        }
+
+        ~auto_mutex (
+        )
+        {
+            unlock();
         }
 
     private:

dlib/threads/auto_mutex_extension_abstract.h

@@ -52,12 +52,21 @@ namespace dlib
                 - m will be locked via m.lock() (i.e. a write lock will be obtained)
         !*/
 
+        void unlock(
+        );
+        /*!
+            ensures
+                - if (unlock() has not already been called) then
+                    - The mutex associated with *this has been unlocked.  This is useful if
+                      you want to unlock a mutex before the auto_mutex destructor executes.
+        !*/
+
         ~auto_mutex (
         );
         /*!
             ensures
                 - all resources allocated by *this have been freed
-                - the mutex associated with *this has been unlocked
+                - calls unlock()
         !*/
 
     private: