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%% options
copyright owner = Dirk Krause
copyright year = 2018-xxxx
SPDX-License-Identifier: BSD-3-Clause
%% header
/** @file Dk4WxProcessingController.h Processing controller to skip
concurrent execution of code accessing the same variables.
@code
class AnyClass {
protected:
Dk4WxProcessingController procon;
...
};
AnyClass::SomeMethod(void)
{
if (procon.CanEnterCriticalSection()) {
... Yes, we are allowed to execute code accessing variable ...
...
... Notify the controller that we are done ...
procon.LeaveCriticalSection();
}
else {
... No, we are not allowed to access the variables ...
}
}
@endcode
*/
#ifndef DK4CONF_H_INCLUDED
#include <dk4conf.h>
#endif
#include <wx/wxprec.h>
#ifdef __BORLANDC__
#pragma hdrstop
#endif
#ifndef WX_PRECOMP
#include <wx/wx.h>
#endif
#ifndef WX_THREAD_H_INCLUDED
#include <wx/thread.h>
#define WX_THREAD_H_INCLUDED 1
#endif
/** Protect code from concurrent execution, mainly for timer handlers.
In contrast to a critical section which delays execution of
code to avoid concurrent access to data this class skips
the execution of concurrent code.
*/
class Dk4WxProcessingController
{
protected:
/** Critical section to protect the "in use" flag.
*/
wxCriticalSection csProtect;
/** Flag to mark section as currently in use.
*/
bool bInUse;
public:
/** Constructor
*/
Dk4WxProcessingController(void);
/** Check whether the critical code section can be entered.
@return True if the section can be entered, false otherwise.
If the method returns true, the bInUse flag is set, you must
call LeaveCriticalSection() to reset it.
*/
bool
CanEnterCriticalSection(void);
/** LeaveCriticalSection the critical section.
*/
void
LeaveCriticalSection(void);
};
/* vim: set ai sw=4 ts=4 : */
%% module
#ifndef DK4CONF_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "dk4conf.h"
#else
#include <dktools-4/dk4conf.h>
#endif
#endif
#ifndef DK4WXCRITICALSECTION_H_INCLUDED
#if DK4_BUILDING_DKTOOLS4
#include "Dk4WxProcessingController.h"
#else
#include <dktools-4/Dk4WxProcessingController.h>
#endif
#endif
Dk4WxProcessingController::Dk4WxProcessingController(void)
{
bInUse = false;
}
bool
Dk4WxProcessingController::CanEnterCriticalSection(void)
{
bool back = false;
{
wxCriticalSectionLocker lock(csProtect);
if (!(bInUse)) {
bInUse = true;
back = true;
}
}
return back;
}
void
Dk4WxProcessingController::LeaveCriticalSection(void)
{
wxCriticalSectionLocker lock(csProtect);
bInUse = false;
}
/* vim: set ai sw=4 ts=4 : */
|