#include <e32base.h>
Link against: euser_v5.lib
| class CAsyncOneShot : public CActive |
| Public Member Functions | |
|---|---|
| CAsyncOneShot(TInt) | |
| virtual | ~CAsyncOneShot() |
| virtual IMPORT_C void | Call() |
| virtual IMPORT_C void | DoCancel() |
| RThread & | Thread() |
| Inherited Attributes | |
|---|---|
| CActive::iStatus | |
| Inherited Enumerations | |
|---|---|
| CActive:TPriority | |
An active object that performs processing that is only performed once.
The active object is intended to be given a low priority, so that it runs only when no higher-priority active objects are ready to run. In addition, the class ensures that the current thread cannot be closed until the active object is destroyed.
The class needs to be derived from to make use of its behaviour, in particular, it needs to define and implement a RunL() function.
NB: the constructor creates a process-relative handle to the current thread and this is stored within this object. If the thread subsequently dies abnormally, then this handle will not be closed, and the thread will not be destroyed until the process terminates.
NB: if Call() is called from a different thread (for example, to implement a kind of inter-thread communication), a client-specific mechanism must be used to ensure that the thread that created this object is still alive.
NB: if the thread that created this object has its own heap and terminates abnormally, then the handle stored within this object is lost.
See also: CActive::RunL CAsyncOneShot::Call
| IMPORT_C | CAsyncOneShot | ( | TInt | aPriority | ) |
Constructor taking a priority value.
Specifically, the constructor:
1. sets this active object's priority value
2. opens a handle to the current thread to ensure that the thread cannot be closed until this CAsyncOneShot object is destroyed
3. adds this active object to the current active scheduler.
| Parameters | |
|---|---|
| aPriority | The active object priority value. CActive::TPriority defines a standard set of priorities. |
| Panic Codes | |
|---|---|
| E32USER-CBase | 93 if the attempt to open a handle to the current thread fails. |
| IMPORT_C | ~CAsyncOneShot | ( | ) | [virtual] |
Frees resources prior to destruction.
Specifically, it closes the handle to the current thread.
See also: CActive::~CActive
| IMPORT_C void | Call | ( | ) | [virtual] |
Queues this active object to be run once.
| Panic Codes | |
|---|---|
| E32USER-CBase | 2 In debug builds only, if this active object has not already been added to the active scheduler. |
| IMPORT_C void | DoCancel | ( | ) | [virtual] |
Reimplemented from CActive::DoCancel()
Implements cancellation of an outstanding request.
The class provides an empty implementation.
This is called by the destructor.
| RThread & | Thread | ( | ) | [inline] |
Gets a handle to the current thread.