dep/ACE_wrappers/ace/Lock_Adapter_T.h

   1 // -*- C++ -*-
   2
   3 //==========================================================================
   4 /**
   5  *  @file    Lock_Adapter_T.h
   6  *
   7  *  $Id: Lock_Adapter_T.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_LOCK_ADAPTER_T_H
  16 #define ACE_LOCK_ADAPTER_T_H
  17 #include /**/ "ace/pre.h"
  18
  19 #include "ace/Lock.h"
  20
  21 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  22 # pragma once
  23 #endif /* ACE_LACKS_PRAGMA_ONCE */
  24
  25 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  26
  27 /**
  28  * @class ACE_Lock_Adapter
  29  *
  30  * @brief This is an adapter that allows applications to transparently
  31  * combine the <ACE_Lock> abstract base class (which contains
  32  * pure virtual methods) with any of the other concrete ACE
  33  * synchronization classes (e.g., ACE_Mutex, ACE_Semaphore,
  34  * ACE_RW_Mutex, etc.).
  35  *
  36  * This class uses a form of the Adapter pattern.
  37  */
  38 template <class ACE_LOCKING_MECHANISM>
  39 class ACE_Lock_Adapter : public ACE_Lock
  40 {
  41 public:
  42   typedef ACE_LOCKING_MECHANISM ACE_LOCK;
  43
  44   // = Initialization/Finalization methods.
  45
  46   /// Constructor. All locking requests will be forwarded to <lock>.
  47   ACE_Lock_Adapter (ACE_LOCKING_MECHANISM &lock);
  48
  49   /// Constructor. Since no lock is provided by the user, one will be
  50   /// created internally.
  51   ACE_Lock_Adapter (void);
  52
  53   /// Destructor. If <lock_> was not passed in by the user, it will be
  54   /// deleted.
  55   virtual ~ACE_Lock_Adapter (void);
  56
  57   // = Lock accessors.
  58   /// Block the thread until the lock is acquired.
  59   virtual int acquire (void);
  60
  61   /// Conditionally acquire the lock (i.e., won't block).
  62   virtual int tryacquire (void);
  63
  64   /// Release the lock.
  65   virtual int release (void);
  66
  67   /**
  68    * Block until the thread acquires a read lock.  If the locking
  69    * mechanism doesn't support read locks then this just calls
  70    * <acquire>.
  71    */
  72   virtual int acquire_read (void);
  73
  74   /**
  75    * Block until the thread acquires a write lock.  If the locking
  76    * mechanism doesn't support read locks then this just calls
  77    * <acquire>.
  78    */
  79   virtual int acquire_write (void);
  80
  81   /// Conditionally acquire a read lock.  If the locking mechanism
  82   /// doesn't support read locks then this just calls <acquire>.
  83   virtual int tryacquire_read (void);
  84
  85   /// Conditionally acquire a write lock.  If the locking mechanism
  86   /// doesn't support read locks then this just calls <acquire>.
  87   virtual int tryacquire_write (void);
  88
  89   /**
  90    * Conditionally try to upgrade a lock held for read to a write lock.
  91    * If the locking mechanism doesn't support read locks then this just
  92    * calls <acquire>. Returns 0 on success, -1 on failure.
  93    */
  94   virtual int tryacquire_write_upgrade (void);
  95
  96   /// Explicitly destroy the lock.
  97   virtual int remove (void);
  98
  99 private:
 100   /// The concrete locking mechanism that all the methods delegate to.
 101   ACE_LOCKING_MECHANISM *lock_;
 102
 103   /// This flag keep track of whether we are responsible for deleting
 104   /// the lock
 105   bool delete_lock_;
 106 };
 107
 108 ACE_END_VERSIONED_NAMESPACE_DECL
 109
 110 #if defined (__ACE_INLINE__)
 111 #include "ace/Lock_Adapter_T.inl"
 112 #endif /* __ACE_INLINE__ */
 113
 114 #if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
 115 #include "ace/Lock_Adapter_T.cpp"
 116 #endif /* ACE_TEMPLATES_REQUIRE_SOURCE */
 117
 118 #if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
 119 #pragma implementation ("Lock_Adapter_T.cpp")
 120 #endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */
 121
 122 #include /**/ "ace/post.h"
 123 #endif /* ACE_LOCK_ADAPTER_T_H */