ACE/ace/Null_Condition.h

   1 // -*- C++ -*-
   2
   3 //==========================================================================
   4 /**
   5  *  @file    Null_Condition.h
   6  *
   7  *   Moved from Synch.h.
   8  *
   9  *  @author Douglas C. Schmidt <d.schmidt@vanderbilt.edu>
  10  */
  11 //==========================================================================
  12
  13 #ifndef ACE_NULL_CONDITION_H
  14 #define ACE_NULL_CONDITION_H
  15 #include /**/ "ace/pre.h"
  16
  17 #include "ace/Null_Mutex.h"
  18 #include "ace/Condition_T.h"
  19
  20 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  21 # pragma once
  22 #endif /* ACE_LACKS_PRAGMA_ONCE */
  23
  24 #include "ace/os_include/os_errno.h"
  25
  26 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  27
  28 class ACE_Time_Value;
  29 class ACE_Condition_Attributes;
  30 template <class MUTEX> class ACE_Condition;
  31
  32 /**
  33  * @brief ACE_Condition template specialization written using
  34  * ACE_Null_Mutexes. Implements a do nothing ACE_Condition
  35  * specialization, i.e., all methods are no ops.
  36  */
  37 template <>
  38 class ACE_Condition<ACE_Null_Mutex>
  39 {
  40 public:
  41   ACE_Condition (const ACE_Null_Mutex &m,
  42                  const ACE_TCHAR * = 0,
  43                  void * = 0)
  44     : mutex_ ((ACE_Null_Mutex &) m) {}
  45
  46   ACE_Condition (const ACE_Null_Mutex &m,
  47                  const ACE_Condition_Attributes &,
  48                  const ACE_TCHAR * = 0,
  49                  void * = 0)
  50   : mutex_ ((ACE_Null_Mutex &) m) {}
  51
  52   ~ACE_Condition (void) {}
  53
  54   /// Returns 0.
  55   int remove (void) {return 0;}
  56
  57   /// Returns -1 with @c errno == @c ETIME.
  58   int wait (const ACE_Time_Value * = 0) {errno = ETIME; return -1;}
  59
  60   /// Returns -1 with @c errno == @c ETIME.
  61   int wait (ACE_Null_Mutex &,
  62             const ACE_Time_Value * = 0) {errno = ETIME; return -1;}
  63
  64   /// Returns 0.
  65   int signal (void) {return 0;}
  66
  67   /// Returns 0.
  68   int broadcast (void) {return 0;}
  69   ACE_Null_Mutex &mutex (void) {return this->mutex_;};
  70
  71   /// Dump the state of an object.
  72   void dump (void) const {}
  73
  74   // ACE_ALLOC_HOOK_DECLARE;
  75   // Declare the dynamic allocation hooks.
  76
  77 protected:
  78   ACE_Null_Mutex &mutex_; // Reference to mutex lock.
  79
  80 private:
  81   // = Prevent assignment and initialization.
  82   void operator= (const ACE_Condition<ACE_Null_Mutex> &);
  83   ACE_Condition (const ACE_Condition<ACE_Null_Mutex> &);
  84 };
  85
  86 typedef ACE_Condition<ACE_Null_Mutex> ACE_Null_Condition;
  87
  88 ACE_END_VERSIONED_NAMESPACE_DECL
  89
  90 #include /**/ "ace/post.h"
  91 #endif /* ACE_NULL_CONDITION_H */