ACE/ace/Null_Condition.h

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