ON_Terminator Class Reference

#include <opennurbs_terminator.h>

Public Member Functions
	ON_Terminator ()
	~ON_Terminator ()
ON__UINT_PTR	CallbackContext () const
ON__UINT_PTR	CallbackFunction () const
void	RequestTermination ()
	Sets m_bTerminationRequested = true. All future calls to TerminationRequested(this) will return true. More...
void	SetTerminationQueryCallbackFunction (bool(*callback_function)(ON__UINT_PTR context), ON__UINT_PTR callback_context)
	Set the function that is called when a calculation wants to determine if the calculation should stop or continue. More...
void	SetThreadId (ON__UINT_PTR thread_id)
ON__UINT_PTR	ThreadId () const

Static Public Member Functions
static void	RequestTermination (ON_Terminator *terminator)
	If terminator is not nullptr, sets terminator->m_bTerminationRequested = true. If terminator is not nullptr, all future calls to TerminationRequested(terminator) will return true. More...
static bool	TerminationRequested (ON_Terminator *terminator)
	A calculation calls ON_Terminator::TerminationRequested(terminator) to determine if it should continue or quit. More...
static bool	TerminationRequestedExpert (ON_Terminator *terminator, ON__UINT64 callback_delta)
	An expert user function to determine if a calculation should continue. More...

Constructor & Destructor Documentation

ON_Terminator()

ON_Terminator::ON_Terminator

(

)

~ON_Terminator()

ON_Terminator::~ON_Terminator

(

)

Member Function Documentation

CallbackContext()

ON__UINT_PTR ON_Terminator::CallbackContext

(

)

const

CallbackFunction()

ON__UINT_PTR ON_Terminator::CallbackFunction

(

)

const

RequestTermination() [1/2]

void ON_Terminator::RequestTermination

(

)

Sets m_bTerminationRequested = true. All future calls to TerminationRequested(this) will return true.

RequestTermination() [2/2]

static void ON_Terminator::RequestTermination ( ON_Terminator *  terminator )

static

If terminator is not nullptr, sets terminator->m_bTerminationRequested = true. If terminator is not nullptr, all future calls to TerminationRequested(terminator) will return true.

Parameters

terminator

[in] (can be nullptr)

This is convenience function and is identical to the code

if (nullptr != terminator) terminator->RequestTermination();

SetTerminationQueryCallbackFunction()

void ON_Terminator::SetTerminationQueryCallbackFunction	(	bool(*)(ON__UINT_PTR context)	callback_function,
		ON__UINT_PTR	callback_context
	)

Set the function that is called when a calculation wants to determine if the calculation should stop or continue.

Parameters

callback_function

[in] The function that is called when a calculation wants to determine if the calculation should stop or continue. If this callback function returns true, the calculation will terminate as soon as possible. If this callback function returns false, the calculation will continue. The calculation thread calls in this callback function. The callback function should do something that is fast and simple. Parameters passed to the callback function:

context

[in] the value of callback_context.

bool bStopCalculation = false;

bool StopCalculation( ON__UINT_PTR context )
{
  if ( 0 != context )
  {
    const bool* p = (const bool*)context;
    if ( *p )
      return true; // terminate calculation as soon as possible
   }
   return false; // continue calculation
}

...

ON_Terminator terminator;
terminator.SetTerminationQueryCallbackFunction(StopCalculation,(ON__UINT_PTR)(&bStopCalculation));
...
Pass &terminator to a calculation and then set bStopCalculation = true to terminate it.
The calculation will generally be running in another thread, but can be in the same
thread if it is structured to pump windows messages or something similar.

SetThreadId()

void ON_Terminator::SetThreadId

(

ON__UINT_PTR

thread_id

)

TerminationRequested()

static bool ON_Terminator::TerminationRequested ( ON_Terminator *  terminator )

static

A calculation calls ON_Terminator::TerminationRequested(terminator) to determine if it should continue or quit.

Parameters

terminator

[in] A pointer to an ON_Terminator or null pointer.

Returns

True if the calculation should terminate as soon as possible. False if the calculation should continue.

void MyLongCalculation( ..., ON_Terminator* terminator, ...)
{
   for ( i = 0; i < count; i++ )
   {
     if ( ON_Terminator::TerminationRequested(terminator) )
       break;
     ...
   }
}

TerminationRequestedExpert()

static bool ON_Terminator::TerminationRequestedExpert ( ON_Terminator *  terminator, ON__UINT64  callback_delta  )

static

An expert user function to determine if a calculation should continue.

Parameters

terminator	[in] A pointer to an ON_Terminator or null pointer.
callback_delta	[in] Minimum amount of time to delay between calls to the registered callback function in clock() time units. 0 will omit making any call to the registered function. ON_Terminator::TerminationRequested( terminator ) uses a value of callback_delta = CLOCKS_PER_SEC/10 meaning a maximum of 10 callbacks per second.

Returns

True if the calculation should terminate as soon as possible. False if the calculation should continue.

In general, call the ON_Terminator::TerminationRequested( terminator ).

ThreadId()

ON__UINT_PTR ON_Terminator::ThreadId

(

)

const