ACE/ace/Lock_Adapter_T.h

   1 // -*- C++ -*-
   2
   3 //==========================================================================
   4 /**
   5  *  @file    Lock_Adapter_T.h
   6  *
   7  *   Moved from Synch.h.
   8  *
   9  *  @author Douglas C. Schmidt <d.schmidt@vanderbilt.edu>
  10  */
  11 //==========================================================================
  12
  13 #ifndef ACE_LOCK_ADAPTER_T_H
  14 #define ACE_LOCK_ADAPTER_T_H
  15 #include /**/ "ace/pre.h"
  16
  17 #include "ace/Lock.h"
  18
  19 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  20 # pragma once
  21 #endif /* ACE_LACKS_PRAGMA_ONCE */
  22
  23 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  24
  25 /**
  26  * @class ACE_Lock_Adapter
  27  *
  28  * @brief This is an adapter that allows applications to transparently
  29  * combine the ACE_Lock abstract base class (which contains
  30  * pure virtual methods) with any of the other concrete ACE
  31  * synchronization classes (e.g., ACE_Mutex, ACE_Semaphore,
  32  * ACE_RW_Mutex, etc.).
  33  *
  34  * This class uses a form of the Adapter pattern.
  35  */
  36 template <class ACE_LOCKING_MECHANISM>
  37 class ACE_Lock_Adapter : public ACE_Lock
  38 {
  39 public:
  40   typedef ACE_LOCKING_MECHANISM ACE_LOCK;
  41
  42   // = Initialization/Finalization methods.
  43
  44   /// Constructor. All locking requests will be forwarded to @a lock.
  45   ACE_Lock_Adapter (ACE_LOCKING_MECHANISM &lock);
  46
  47   /// Constructor. Since no lock is provided by the user, one will be
  48   /// created internally.
  49   ACE_Lock_Adapter (void);
  50
  51   /// Destructor. If @c lock_ was not passed in by the user, it will be
  52   /// deleted.
  53   virtual ~ACE_Lock_Adapter (void);
  54
  55   // = Lock accessors.
  56   /// Block the thread until the lock is acquired.
  57   virtual int acquire (void);
  58
  59   /// Conditionally acquire the lock (i.e., won't block).
  60   virtual int tryacquire (void);
  61
  62   /// Release the lock.
  63   virtual int release (void);
  64
  65   /**
  66    * Block until the thread acquires a read lock.  If the locking
  67    * mechanism doesn't support read locks then this just calls
  68    * acquire().
  69    */
  70   virtual int acquire_read (void);
  71
  72   /**
  73    * Block until the thread acquires a write lock.  If the locking
  74    * mechanism doesn't support read locks then this just calls
  75    * acquire().
  76    */
  77   virtual int acquire_write (void);
  78
  79   /// Conditionally acquire a read lock.  If the locking mechanism
  80   /// doesn't support read locks then this just calls acquire().
  81   virtual int tryacquire_read (void);
  82
  83   /// Conditionally acquire a write lock.  If the locking mechanism
  84   /// doesn't support read locks then this just calls acquire().
  85   virtual int tryacquire_write (void);
  86
  87   /**
  88    * Conditionally try to upgrade a lock held for read to a write lock.
  89    * If the locking mechanism doesn't support read locks then this just
  90    * calls acquire(). Returns 0 on success, -1 on failure.
  91    */
  92   virtual int tryacquire_write_upgrade (void);
  93
  94   /// Explicitly destroy the lock.
  95   virtual int remove (void);
  96
  97 private:
  98   /// The concrete locking mechanism that all the methods delegate to.
  99   ACE_LOCKING_MECHANISM *lock_;
 100
 101   /// This flag keep track of whether we are responsible for deleting
 102   /// the lock
 103   bool delete_lock_;
 104 };
 105
 106 ACE_END_VERSIONED_NAMESPACE_DECL
 107
 108 #if defined (__ACE_INLINE__)
 109 #include "ace/Lock_Adapter_T.inl"
 110 #endif /* __ACE_INLINE__ */
 111
 112 #if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
 113 #include "ace/Lock_Adapter_T.cpp"
 114 #endif /* ACE_TEMPLATES_REQUIRE_SOURCE */
 115
 116 #if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
 117 #pragma implementation ("Lock_Adapter_T.cpp")
 118 #endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */
 119
 120 #include /**/ "ace/post.h"
 121 #endif /* ACE_LOCK_ADAPTER_T_H */