TAO/tao/Condition.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    Condition.h
   6  *
   7  *  @author From ACE to TAO by Balachandran Natarajan <bala@cs.wustl.edu>
   8  */
   9 //=============================================================================
  10
  11 #ifndef TAO_CONDITION_H
  12 #define TAO_CONDITION_H
  13
  14 #include /**/ "ace/pre.h"
  15
  16 #include "tao/orbconf.h"
  17
  18 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  19 # pragma once
  20 #endif /* ACE_LACKS_PRAGMA_ONCE */
  21
  22 #include "ace/Condition_T.h"
  23 #include "ace/Global_Macros.h"
  24
  25 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  26 class ACE_Time_Value;
  27 ACE_END_VERSIONED_NAMESPACE_DECL
  28
  29 TAO_BEGIN_VERSIONED_NAMESPACE_DECL
  30
  31 /**
  32  * @class TAO_Condition
  33  *
  34  * @brief Same as to the ACE_Condition variable wrapper
  35  *
  36  * This class differs from ACE_Condition in that it uses a
  37  * TAO_SYNCH_CONDITION instead of ACE_cond_t under the hood to
  38  * provide blocking.
  39  */
  40 template <class MUTEX>
  41 class TAO_Condition
  42 {
  43 public:
  44   /// Useful typedef
  45   typedef MUTEX LOCK;
  46
  47   // = Initialiation and termination methods.
  48   /// Initialize the condition variable.
  49   TAO_Condition (MUTEX &m);
  50
  51   /// A default constructor. Since no lock is provided by the user,
  52   /// one will be created internally.
  53   TAO_Condition ();
  54
  55   /// Implicitly destroy the condition variable.
  56   ~TAO_Condition ();
  57
  58   // = Lock accessors.
  59   /**
  60    * Block on condition, or until absolute time-of-day has passed.  If
  61    * abstime == 0 use "blocking" <wait> semantics.  Else, if <abstime>
  62    * != 0 and the call times out before the condition is signaled
  63    * <wait> returns -1 and sets errno to ETIME.
  64    */
  65   int wait (const ACE_Time_Value *abstime);
  66
  67   /// Block on condition.
  68   int wait ();
  69
  70   /**
  71    * Block on condition or until absolute time-of-day has passed.  If
  72    * abstime == 0 use "blocking" wait() semantics on the <mutex>
  73    * passed as a parameter (this is useful if you need to store the
  74    * <Condition> in shared memory).  Else, if <abstime> != 0 and the
  75    * call times out before the condition is signaled <wait> returns -1
  76    * and sets errno to ETIME.
  77    */
  78   int wait (MUTEX &mutex, const ACE_Time_Value *abstime = 0);
  79
  80   /// Signal one waiting thread.
  81   int signal ();
  82
  83   /// Signal *all* waiting threads.
  84   int broadcast ();
  85
  86   // = Utility methods.
  87   /// Explicitly destroy the condition variable.
  88   int remove ();
  89
  90   /// Returns a reference to the underlying mutex_;
  91   MUTEX *mutex ();
  92
  93 private:
  94   TAO_Condition (const TAO_Condition<MUTEX> &) = delete;
  95   TAO_Condition &operator= (const TAO_Condition<MUTEX> &) = delete;
  96
  97   /// Reference to mutex lock.
  98   MUTEX *mutex_;
  99
 100   /// A flag to indicate whether the lock needs to be deleted.
 101   bool delete_lock_;
 102
 103   /// Condition variable.
 104   TAO_SYNCH_CONDITION *cond_;
 105 };
 106
 107 TAO_END_VERSIONED_NAMESPACE_DECL
 108
 109 #if defined (__ACE_INLINE__)
 110 #include "tao/Condition.inl"
 111 #endif /* __ACE_INLINE__ */
 112
 113 #include "tao/Condition.cpp"
 114
 115 #include /**/ "ace/post.h"
 116 #endif /*TAO_CONDITION_H*/