Class RHandleBase

class RHandleBase;

Description

A handle to an object.

The class encapsulates the basic behaviour of a handle, hiding the handle-number which identifies the object which the handle represents.

The class is abstract in the sense that a RHandleBase object is never explicitly instantiated. It is always a base class to a concrete handle class; for example, RSemaphore, RThread, RProcess, RCriticalSection etc.

Members

Defined in RHandleBase:

• Attributes()const
• BTraceId()constReturns a unique object identifier for use with BTrace
• Close()Closes the handle.
• Duplicate(const RThread &,TOwnerType)Creates a valid handle to the kernel object for which the specified thread alrea...
• FullName()constGets the full name of the handle.
• FullName(TDes &)constGets the full name of the handle.
• Handle()constRetrieves the handle-number of the object associated with this handle.
• HandleInfo(THandleInfo *)Gets information about the handle.
• Name()constGets the name of the handle.
• Open(const TFindHandleBase &,TOwnerType)Opens a handle to a kernel side object found using a find-handle object.
• RHandleBase()Default constructor.
• RHandleBase(TInt)Copy constructor.
• SetHandle(TInt)Sets the handle-number of this handle to the specified value.
• SetHandleNC(TInt)Sets the handle-number of this handle to the specified value, and marks it as no...
• SetReturnedHandle(TInt)Sets the handle-number of this handle to the specified value.
• iHandle

inline RHandleBase();

Description

Default constructor.

protected: inline RHandleBase(TInt aHandle);

Description

Copy constructor.

It constructs this handle from an existing one. Specifically, the handle-number encapsulated by the specified handle is copied to this handle.

Parameters

inline TInt Handle() const;

Description

Retrieves the handle-number of the object associated with this handle.

Return value

inline void SetHandle(TInt aHandle);

Description

Sets the handle-number of this handle to the specified value.

Parameters

inline TInt SetReturnedHandle(TInt aHandleOrError);

Description

Sets the handle-number of this handle to the specified value.

The function can take a (zero or positive) handle-number, or a (negative) error number.

If aHandleOrError represents a handle-number, then the handle-number of this handle is set to that value. If aHandleOrError represents an error number, then the handle-number of this handle is set to zero and the negative value is returned.

Parameters

Return value

IMPORT_C void Close();

Description

Closes the handle.

This has the effect of closing the associated kernel side object.

As the associated object is a reference counting object, it is destroyed if there are no other open references to it.

IMPORT_C TName Name() const;

Description

Gets the name of the handle.

Return value

IMPORT_C TFullName FullName() const;

Description

Gets the full name of the handle.

Note: This method is stack consuming (it takes 512 bytes on stack to execute). For an alternative way to obtain the full name of the object, see RHandleBase::FullName(TDes &)const.

Return value

See also:

• RHandleBase::FullName(TDes &)constGets the full name of the handle.

IMPORT_C void FullName(TDes &aName) const;

Description

Gets the full name of the handle.

Parameters

Panic codes

IMPORT_C void SetHandleNC(TInt aHandle);

Description

Sets the handle-number of this handle to the specified value, and marks it as not closable.

Parameters

IMPORT_C TInt Duplicate(const RThread &aSrc, TOwnerType aType=EOwnerProcess);

Description

Creates a valid handle to the kernel object for which the specified thread already has a handle.

The function assumes that this handle has been copy constructed from an existing handle (or the handle-number has been explicitly copied through calls to RHandleBase::Handle()const and RHandleBase::SetHandle(TInt)).

By default, any thread in the process can use this handle to access the kernel side object that the handle represents. However, specifying EOwnerThread as the second parameter to this function, means that only the creating thread can use this handle to access the kernel side object; any other thread in this process that wants to access the kernel side object must, again, duplicate this handle.

Parameters

Return value

IMPORT_C void HandleInfo(THandleInfo *anInfo);

Description

Gets information about the handle.

Parameters

IMPORT_C TUint Attributes() const;

Description

Return value

IMPORT_C TInt BTraceId() const;

Description

Returns a unique object identifier for use with BTrace

Return value

protected: IMPORT_C TInt Open(const TFindHandleBase &aHandle, TOwnerType aType);

Description

Opens a handle to a kernel side object found using a find-handle object.

Parameters

Return value

protected: TInt iHandle;

Description