1 files changed, 100 insertions, 0 deletions
diff --git a/ACE/ace/OS_Errno.h b/ACE/ace/OS_Errno.h
new file mode 100644
index 00000000000..e92837af318
--- /dev/null
+++ b/ACE/ace/OS_Errno.h
@@ -0,0 +1,100 @@
+// -*- C++ -*-
+
+//=============================================================================
+/**
+ *  @file   OS_Errno.h
+ *
+ *  $Id$
+ *
+ *  @author (Originally in OS.h)Doug Schmidt <schmidt@cs.wustl.edu>
+ */
+//=============================================================================
+
+#ifndef ACE_OS_ERRNO_H
+#define ACE_OS_ERRNO_H
+#include /**/ "ace/pre.h"
+
+#include "ace/ACE_export.h"
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+# pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+#include "ace/OS_NS_errno.h"
+
+ACE_BEGIN_VERSIONED_NAMESPACE_DECL
+
+/**
+ * @class ACE_Errno_Guard
+ *
+ * @brief Provides a wrapper to improve performance when thread-specific
+ * errno must be saved and restored in a block of code.
+ *
+ * The typical use-case for this is the following:
+ * int error = errno;
+ * call_some_function_that_might_change_errno ();
+ * errno = error;
+ * This can be replaced with
+ * {
+ * ACE_Errno_Guard guard (errno);
+ * call_some_function_that_might_change_errno ();
+ * }
+ * This implementation is more elegant and more efficient since it
+ * avoids an unnecessary second access to thread-specific storage
+ * by caching a pointer to the value of errno in TSS.
+ */
+class ACE_Export ACE_Errno_Guard
+{
+public:
+  ///  Stash the value of <error> into <error_> and initialize the
+  ///  <errno_ptr_> to the address of <errno_ref>.
+  ACE_Errno_Guard (ACE_ERRNO_TYPE &errno_ref,
+                   int error);
+
+  ///  Stash the value of <errno> into <error_> and initialize the
+  ///  <errno_ptr_> to the address of <errno_ref>.
+  ACE_Errno_Guard (ACE_ERRNO_TYPE &errno_ref);
+
+  /// Reset the value of <errno> to <error>.
+  ~ACE_Errno_Guard (void);
+
+#if defined (ACE_HAS_WINCE_BROKEN_ERRNO)
+  /// Assign <errno_ref> to <error_>.
+  int operator= (const ACE_ERRNO_TYPE &errno_ref);
+#endif /* ACE_HAS_WINCE_BROKEN_ERRNO */
+
+  /// Assign <error> to <error_>.
+  int operator= (int error);
+
+  /// Compare <error> with <error_> for equality.
+  bool operator== (int error);
+
+  /// Compare <error> with <error_> for inequality.
+  bool operator!= (int error);
+
+private:
+  // Prevent copying
+  ACE_Errno_Guard (const ACE_Errno_Guard &);
+  ACE_Errno_Guard &operator= (const ACE_Errno_Guard &);
+
+#if defined (ACE_MT_SAFE)
+  ACE_ERRNO_TYPE *errno_ptr_;
+#endif /* ACE_MT_SAFE */
+  int error_;
+};
+
+ACE_END_VERSIONED_NAMESPACE_DECL
+
+// Inlining this class on debug builds with gcc on Solaris can cause
+// deadlocks during static initialization.
+#if defined (ACE_HAS_INLINED_OSCALLS) && \
+    (!defined (__GNUG__) || !defined (__sun__) || defined (ACE_NDEBUG))
+# if defined (ACE_INLINE)
+#  undef ACE_INLINE
+# endif /* ACE_INLINE */
+# define ACE_INLINE inline
+# include "ace/OS_Errno.inl"
+#endif /* ACE_HAS_INLINED_OSCALLS */
+
+#include /**/ "ace/post.h"
+#endif /* ACE_OS_ERRNO_H */