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diff --git a/ace/Svc_Conf_Lexer_Guard.h b/ace/Svc_Conf_Lexer_Guard.h
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+// -*- C++ -*-
+
+//=============================================================================
+/**
+ *  @file    Svc_Conf_Lexer_Guard.h
+ *
+ *  $Id$
+ *
+ *  @author Ossama Othman <ossama@uci.edu>
+ */
+//=============================================================================
+
+#ifndef ACE_SVC_CONF_LEXER_GUARD_H
+#define ACE_SVC_CONF_LEXER_GUARD_H
+
+#include /**/ "ace/pre.h"
+
+#include "ace/config-all.h"
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+# pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+/// Forward declarations
+class ACE_Svc_Conf_Param;
+
+struct ace_yy_buffer_state;
+
+/**
+ * @class ACE_Svc_Conf_Lexer_Guard
+ *
+ * @brief "Guard" that ensures lexer buffer switching is
+ *        exception-safe.
+ *
+ * Buffers are switched, if necessary, each time a token is
+ * parsed/scanned.  The buffer switching must be synchronized
+ * externally.  This class performs no synchronization.
+ *
+ * @note Note that allocation/deallocation is done once during the
+ *       processing of a service configurator directive.  Memory
+ *       managements is done at a higher level, not in this class.
+ *       This is necessary to prevent an allocation/deallocation from
+ *       occurring when parsing/scanning each token.
+ */
+class ACE_Svc_Conf_Lexer_Guard
+{
+public:
+
+  /// Constructor
+  /**
+   * Switches buffers, if necessary, when token scanning first
+   * begins.  Allocation of the buffer will also occur if one has not
+   * already been allocated.  This operation effectively pushes a
+   * buffer on to a stack.
+   */
+  ACE_Svc_Conf_Lexer_Guard (ACE_Svc_Conf_Param *param);
+
+  /// Destructor
+  /**
+   * Switches buffers, if necessary when token scanning completes.  No
+   * buffer deallocation occurs here.  Buffers are deallocated when
+   * parsing of the entire directive is done, not when scanning of a
+   * single token is done.  This operation effective pops a buffer off
+   * of a stack.
+   */
+  ~ACE_Svc_Conf_Lexer_Guard (void);
+
+private:
+
+  /// Lexer buffer that corresponds to the current Service
+  /// Configurator file/direct scan.
+  ace_yy_buffer_state *buffer_;
+
+};
+
+
+#include /**/ "ace/post.h"
+
+#endif  /* ACE_SVC_CONF_LEXER_GUARD_H */