CActiveSchedulerWait Class Reference

#include <e32base.h>

Link against: euser_v5.lib

class CActiveSchedulerWait : public CBase

Inherits from

CActiveSchedulerWait
- CBase

Public Member Functions
	CActiveSchedulerWait()
	~CActiveSchedulerWait()
IMPORT_C void	AsyncStop()
IMPORT_C void	AsyncStop(const TCallBack &)
IMPORT_C TBool	CanStopNow()
TBool	IsStarted()
IMPORT_C void	Start()

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()

Detailed Description

Controls a single scheduling loop in the current active scheduler.

This class provides better control of nested wait loops in the active scheduler.

Note that a CActiveSchedulerWait object can be used as a data member inside other CBase derived classes.

Constructor & Destructor Documentation

CActiveSchedulerWait ( )

IMPORT_C

CActiveSchedulerWait

(

)

Default constructor.

~CActiveSchedulerWait ( )

IMPORT_C

~CActiveSchedulerWait

(

)

Ensures that the attached scheduler loop, and all nested loops, are stopped prior to destruction.

Member Function Documentation

AsyncStop ( )

IMPORT_C void

AsyncStop

(

)

Stops the scheduling loop owned by this object.

Note that the corresponding call to Start() only returns once all nested scheduler loops have stopped.

Panic Codes
E32USER-CBase	92 if the wait object has not been started.

AsyncStop ( const TCallBack & )

IMPORT_C void

AsyncStop

(

const TCallBack &

aCallMeWhenStopped

)

Stops the scheduling loop owned by this object, specifying a callback.

This version of AsyncStop() provides a callback which is invoked immediately after the scheduler loop actually stops before the corresponding call to Start() returns.

Note that the corresponding call to Start() only returns once all nested scheduler loops have stopped.

Parameters
aCallMeWhenStopped	The callback to invoke when the scheduler loop exits.

Panic Codes
E32USER-CBase	92 if the wait object has not been started.

CanStopNow ( )

IMPORT_C TBool

CanStopNow

(

)

const

Reports whether stopping will have immediate effect.

This returns an indication of whether a call to AsyncStop() would be expected to stop the scheduler loop immediately, or whether it will have to wait until nested scheduler loops have stopped. This may alter which version of AsyncStop() you would want to call.

Return Value: Boolean indicating if the scheduling loop would stop immediately.

Panic Codes
E32USER-CBase	92 if the wait object has not been started.

IsStarted ( )

TBool

IsStarted

(

)

const [inline]

Reports whether this CActiveSchedulerWait object is currently started.

Note: a CActiveSchedulerWait object itself becomes "stopped" as soon as AsyncStop() is called, and can be started again immediately if required (but this would start a new nested level of the scheduler).

Return Value: True if the scheduling loop is active; false, otherwise.

Start ( )

IMPORT_C void

Start

(

)

Starts a new wait loop under the control of the current active scheduler.

Compared with CActiveScheduler::Start(), this object owns control of the scheduling loop that is started, and that loop can only be stopped by using this objects AsyncStop() function or the CActiveScheduler::Halt() function. Start() only returns when either of thos has occurred.

This is the preferred way to start a nested wait loop. Typically, a nested wait loop is used when the handling of a completed event in an active object requires processing further events from the other active objects before it can complete. This is a form of modal processing.

Panic Codes
E32USER-CBase	44 if the thread does not have an active scheduler installed.
E32USER-CBase	91 if this object has already been started.