dep/ACE_wrappers/ace/RW_Thread_Mutex.h

   1 // -*- C++ -*-
   2
   3 //==========================================================================
   4 /**
   5  *  @file    RW_Thread_Mutex.h
   6  *
   7  *  $Id: RW_Thread_Mutex.h 80826 2008-03-04 14:51:23Z wotte $
   8  *
   9  *   Moved from Synch.h.
  10  *
  11  *  @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
  12  */
  13 //==========================================================================
  14
  15 #ifndef ACE_RW_THREAD_MUTEX_H
  16 #define ACE_RW_THREAD_MUTEX_H
  17 #include /**/ "ace/pre.h"
  18
  19 #include /**/ "ace/ACE_export.h"
  20
  21 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  22 # pragma once
  23 #endif /* ACE_LACKS_PRAGMA_ONCE */
  24
  25 #if !defined (ACE_HAS_THREADS)
  26 #  include "ace/Null_Mutex.h"
  27 #else /* ACE_HAS_THREADS */
  28 // ACE platform supports some form of threading.
  29
  30 #include "ace/RW_Mutex.h"
  31
  32 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  33
  34 /**
  35  * @class ACE_RW_Thread_Mutex
  36  *
  37  * @brief Wrapper for readers/writer locks that exist within a process.
  38  */
  39 class ACE_Export ACE_RW_Thread_Mutex : public ACE_RW_Mutex
  40 {
  41 public:
  42   ACE_RW_Thread_Mutex (const ACE_TCHAR *name = 0,
  43                        void *arg = 0);
  44
  45   /// Default dtor.
  46   ~ACE_RW_Thread_Mutex (void);
  47
  48   /**
  49    * Conditionally upgrade a read lock to a write lock.  This only
  50    * works if there are no other readers present, in which case the
  51    * method returns 0.  Otherwise, the method returns -1 and sets
  52    * @c errno to @c EBUSY.  Note that the caller of this method *must*
  53    * already possess this lock as a read lock (but this condition is
  54    * not checked by the current implementation).
  55    */
  56   int tryacquire_write_upgrade (void);
  57
  58   /// Dump the state of an object.
  59   void dump (void) const;
  60
  61   /// Declare the dynamic allocation hooks.
  62   ACE_ALLOC_HOOK_DECLARE;
  63 };
  64
  65 ACE_END_VERSIONED_NAMESPACE_DECL
  66
  67 #if defined (__ACE_INLINE__)
  68 #include "ace/RW_Thread_Mutex.inl"
  69 #endif /* __ACE_INLINE__ */
  70
  71 #endif /* !ACE_HAS_THREADS */
  72
  73 #include /**/ "ace/post.h"
  74 #endif /* ACE_RW_THREAD_MUTEX_H */