ACE/ace/RW_Thread_Mutex.h

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