office-gobmx/framework/inc/threadhelp/irwlock.h

87 lines
4.4 KiB
C++

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#ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_
#define __FRAMEWORK_THREADHELP_IRWLOCK_H_
//_________________________________________________________________________________________________________________
// includes
//_________________________________________________________________________________________________________________
//_________________________________________________________________________________________________________________
// namespace
//_________________________________________________________________________________________________________________
namespace framework{
//_________________________________________________________________________________________________________________
// declarations
//_________________________________________________________________________________________________________________
/*-************************************************************************************************************//**
@descr A guard (specialy a write guard) support different internal working states.
His lock can set for reading or writing/reading! Or he was unlocked by user ...
*//*-*************************************************************************************************************/
enum ELockMode
{
E_NOLOCK ,
E_READLOCK ,
E_WRITELOCK
};
/*-************************************************************************************************************//**
@descr We implement two guards for using an rw-lock. But if you wish to implement
different rw-locks to you will have problems by using with same guard implementation!
Thats why we define this "pure virtual base class" ...
All rw-locks must support this base interface for working and all guard must use this one too!
*//*-*************************************************************************************************************/
class IRWLock
{
//-------------------------------------------------------------------------------------------------------------
// public methods
//-------------------------------------------------------------------------------------------------------------
public:
/*-****************************************************************************************************//**
@descr These functions must be supported by a derived class!
acquireReadAccess() -try to register thread as reader
releaseReadAccess() -unregister thread as reader
acquireWriteAccess() -try to register thread as writer
releaseWriteAccess() -unregister thread as writer
downgradeWriteAccess() -make writer to reader
*//*-*****************************************************************************************************/
virtual void acquireReadAccess () =0;
virtual void releaseReadAccess () =0;
virtual void acquireWriteAccess () =0;
virtual void releaseWriteAccess () =0;
virtual void downgradeWriteAccess () =0;
}; // class IRWLock
} // namespace framework
#endif // #ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_