framework/inc/threadhelp/irwlock.h

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  30
  31 #ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_
  32 #define __FRAMEWORK_THREADHELP_IRWLOCK_H_
  33
  34 //_________________________________________________________________________________________________________________
  35 //      includes
  36 //_________________________________________________________________________________________________________________
  37
  38 //_________________________________________________________________________________________________________________
  39 //      namespace
  40 //_________________________________________________________________________________________________________________
  41
  42 namespace framework{
  43
  44 //_________________________________________________________________________________________________________________
  45 //      declarations
  46 //_________________________________________________________________________________________________________________
  47
  48 /*-************************************************************************************************************//**
  49     @descr                      A guard (specialy a write guard) support different internal working states.
  50                     His lock can set for reading or writing/reading! Or he was unlocked by user ...
  51 *//*-*************************************************************************************************************/
  52 enum ELockMode
  53 {
  54     E_NOLOCK    ,
  55     E_READLOCK  ,
  56     E_WRITELOCK
  57 };
  58
  59 /*-************************************************************************************************************//**
  60     @descr                      We implement two guards for using an rw-lock. But if you wish to implement
  61                     different rw-locks to you will have problems by using with same guard implementation!
  62                     Thats why we define this "pure virtual base class" ...
  63                     All rw-locks must support this base interface for working and all guard must use this one too!
  64 *//*-*************************************************************************************************************/
  65 class IRWLock
  66 {
  67     //-------------------------------------------------------------------------------------------------------------
  68     //  public methods
  69     //-------------------------------------------------------------------------------------------------------------
  70     public:
  71
  72         /*-****************************************************************************************************//**
  73             @descr              These functions must be supported by a derived class!
  74                             acquireReadAccess()         -try to register thread as reader
  75                             releaseReadAccess()         -unregister thread as reader
  76                             acquireWriteAccess()        -try to register thread as writer
  77                             releaseWriteAccess()        -unregister thread as writer
  78                             downgradeWriteAccess()      -make writer to reader
  79         *//*-*****************************************************************************************************/
  80         virtual void acquireReadAccess    () =0;
  81         virtual void releaseReadAccess    () =0;
  82         virtual void acquireWriteAccess   () =0;
  83         virtual void releaseWriteAccess   () =0;
  84         virtual void downgradeWriteAccess () =0;
  85
  86 };              //      class IRWLock
  87
  88 }               //      namespace framework
  89
  90 #endif  //      #ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_