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diff --git a/ACE/ace/RW_Process_Mutex.h b/ACE/ace/RW_Process_Mutex.h
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+++ b/ACE/ace/RW_Process_Mutex.h
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+// -*- C++ -*-
+//
+//=============================================================================
+/**
+ *  @file    RW_Process_Mutex.h
+ *
+ *  $Id$
+ *
+ *  @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
+ */
+//=============================================================================
+
+#ifndef ACE_RW_PROCESS_MUTEX_H
+#define ACE_RW_PROCESS_MUTEX_H
+
+#include /**/ "ace/pre.h"
+
+#include "ace/File_Lock.h"
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+# pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+#include "ace/Default_Constants.h"
+
+ACE_BEGIN_VERSIONED_NAMESPACE_DECL
+
+/**
+ * @class ACE_RW_Process_Mutex
+ *
+ * @brief Wrapper for readers/writer locks that exist across processes.
+ *
+ * @note This class uses an ACE_File_Lock as its implementation. Thus, it
+ * can only be reliably used between separate processes, rather than
+ * threads in the same process.  This isn't a limitation of ACE, it's simply
+ * the file lock semantics on UNIX and Win32.
+ *
+ * @todo For systems with pthread_rwlockattr_setpshared one
+ * may consider using them to make the mutex faster.
+ */
+class ACE_Export ACE_RW_Process_Mutex
+{
+public:
+  /// Create a cross-process readers/writer mutex, passing in the optional
+  /// @a name, @a flags and @a mode \sa ACE_File_Lock.
+  /// If not specified, a name is generated and flags and mode are set
+  /// to default platform values.
+  ACE_RW_Process_Mutex (const ACE_TCHAR *name = 0,
+                        int flags = O_CREAT|O_RDWR,
+                        mode_t mode =  ACE_DEFAULT_RW_PROCESS_MUTEX_PERMS);
+
+  ~ACE_RW_Process_Mutex (void);
+
+  /**
+   * Explicitly destroy the mutex.  Note that only one thread should
+   * call this method since it doesn't protect against race
+   * conditions.
+   */
+  int remove (void);
+
+  /// Same as acquire_write().
+  /// Acquire lock ownership; blocks until the lock is acquired or the
+  /// operation fails.
+  int acquire (void);
+
+  /**
+   * Same as tryacquire_write().
+   * Try to acquire the lock, but do not block if the lock is not immediately
+   * acquired.
+   *
+   * @retval -1 on failure. If the lock is already held, @c errno is set
+   *         to @c EBUSY.
+   */
+  int tryacquire (void);
+
+  /// Release lock.
+  int release (void);
+
+  /// Acquire read lock; blocks until the lock is acquired or the
+  /// operation fails.
+  int acquire_read (void);
+
+  /// Acquire write lock; blocks until the lock is acquired or the
+  /// operation fails.
+  int acquire_write (void);
+
+  /**
+   * Try to acquire the read lock, but do not block if the lock is not
+   * immediately acquired.
+   *
+   * @retval -1 on failure. If the lock is already held, @c errno is set
+   *         to @c EBUSY.
+   */
+  int tryacquire_read (void);
+
+  /**
+   * Try to acquire the write lock, but do not block if the lock is not
+   * immediately acquired.
+   *
+   * @retval -1 on failure. If the lock is already held, @c errno is set
+   *         to @c EBUSY.
+   */
+  int tryacquire_write (void);
+
+  /// Attempt to upgrade a read lock to a write lock. Returns 0 on
+  /// success, -1 on failure.
+  int tryacquire_write_upgrade (void);
+
+  /// Return the underlying lock.
+  const ACE_File_Lock &lock (void) const;
+
+  /// Dump the state of an object.
+  void dump (void) const;
+
+  /// Declare the dynamic allocation hooks.
+  ACE_ALLOC_HOOK_DECLARE;
+
+private:
+  /// If the user does not provide a name we generate a unique name in
+  /// this buffer.
+  ACE_TCHAR name_[ACE_UNIQUE_NAME_LEN];
+
+  /// Create and return the unique name.
+  const ACE_TCHAR *unique_name (void);
+
+  /// We need this to get the readers/writer semantics...
+  ACE_File_Lock lock_;
+};
+
+ACE_END_VERSIONED_NAMESPACE_DECL
+
+#if defined (__ACE_INLINE__)
+#include "ace/RW_Process_Mutex.inl"
+#endif /* __ACE_INLINE__ */
+
+#include /**/ "ace/post.h"
+#endif /* ACE_RW_PROCESS_MUTEX_H */