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1-132 SOMobjects Base Toolkit: Programmer’s Reference Manual

somDestruct Method

Purpose

Uninitializes the receiving object, and (if so directed) frees object storage after

uninitialization has been completed. Replaces somUninit as the preferred method for

uninitializing objects. For performance reasons, it is recommended that somDestruct

always be overridden. Not normally invoked directly by object clients.

Syntax

void somDestruct (in octet dofree, inout somDestructCtrl ctrl);

Description

Every class must support the somDestruct method. This is accomplished either by

overriding somDestruct (in which case a specialized stub procedure will be generated in

the implementation template file), or else SOMobjects will automatically provide a generic

procedure that implements somDestruct for the class. The generic procedure calls

somUninit (if this was overridden) to perform local uninitialization, then completes

execution of the method appropriately.

Because the specialized stub procedure generated by the template emitter is more efficient

than the generic procedure provided when somDestruct is not overridden, it is

recommended that somDestruct always be overridden. The stub procedure that is

generated in this case requires no modification for correct operation. The only modification

appropriate within this stub procedure is to uninitialize locally introduced instance variables.

See Section 5.5, “Initializing and Uninitializing Objects,” of the SOMobjects Developer

Toolkit Users Guide for further details.

Uninitialization with somDestruct executes as follows: For any given class in the ancestor

chain, somDestruct first uninitializes that class’s introduced instance variables (if this is

appropriate), and then calls the next ancestor class’s implementation of somDestruct,

passing 0 (that is, false) as the interim dofree argument. Then, after all ancestors of the

given class have been uninitialized, if the class’s own somDestruct method were originally

invoked with dofree as 1 (that is, true), then that object’s storage is released.

Note: It is not appropriate to override both somDestruct and somUninit. If this is done,

the somUninit code will not be executed. The best way to convert an old class that

overrides somUninit to use of the more efficient somDestruct (if this is desired) is

as follows: (1) Replace the somUninit override in the class’s .idl file with an override

for somDestruct, (2) run the emitter to produce a stub procedure for somDestruct

in the implementation template file, and then (3) simply call the class’s somUninit

procedure directly (not using a method invocation) from the somDestruct

procedure.

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