Topic: vlax-release-object

[QuestionEverything]

Hello everybody,
This code is not mine:

Code: [Select]

(defun c:ATxt (/ VlaObjLine LinAngle VlaObjText )
(vl-load-com )
(setq VlaObjLine (vlax-ename->vla-object (car (entsel "\nSelect line: " ))) )
(setq LinAngle (vla-get-Angle VlaObjLine ) )
(while (setq VlaObjText (vlax-ename->vla-object (car (entsel "\nSelect text : " ))))
(vla-put-Rotation VlaObjText LinAngle )
(vlax-release-object VlaObjText )
)
(vlax-release-object VlaObjLine )
(princ)
)I wanted to ask why "vlax-release-object" is used, and is this is necessary?

Usually I've seen it used like this:

Code: [Select]

(setq Obj (vlax-get-or-create-object "WScript.Shell"))
; do something
(vlax-release-object Obj)


[Lee Mac]

There is no firm documentation, but it is generally only considered necessary to release objects outside of the scope of the AutoCAD Object Model - there are many similar threads which discuss this.

[QuestionEverything]

I just found some good thread about this, still makes no sence for me for being used in that code.

After not carefully reading it now I know that:

(vlax-release-object) destroys the pointer of the object, It doesn’t destroy the "object" but the memory for that object.
Used (vlax-dump-object), after that (vlax-release-object), and then (vlax-dump-object) again:

Code: [Select]

_$ (setq e (car (entsel)))
<Entity name: 7ff666a073a0>
_$ (setq o (vlax-ename->vla-object e))
#<VLA-OBJECT IAcadCircle 00000064758ab718>
_$ o
#<VLA-OBJECT IAcadCircle 00000064758ab718>
_$ (vlax-dump-object o)
; IAcadCircle: AutoCAD Circle Interface
; Property values:
...
T
_$ (vlax-release-object o)
0
_$ o
#<VLA-OBJECT 0000000000000000>
_$ (vlax-dump-object o)
; Object is not connected
nil
_$


tried the "inspect tool" after (vlax-release-object):

Code: [Select]

_$ o
#<VLA-OBJECT 0000000000000000>
_$

Error: null interface pointer: #<VLA-OBJECT 0000000000000000>
_1$
So the conclusion I did: is to "release" any object that is assigned as a local variable inside a function (after its use).
In order to free any pontentially used memory when the routine ends.

[Lee Mac]

So the conclusion I did: is to "release" any object that is assigned as a local variable inside a function (after its use).
In order to free any pontentially used memory when the routine ends.

Not absolutely necessary, as AutoCAD will perform its own garbage collection.

[QuestionEverything]

Not absolutely necessary, as AutoCAD will perform its own garbage collection.

Hm okay, but is there any further action required? Like "empten the garbage" ?

Looks like its enough to follow this advice:

From what I have read and experienced, you only need to use the vlax-release-object on symbols that were set with vlax-get-object, vlax-create-object, vlax-get-or-create-object or with the method "getinterfaceobject".

[Lee Mac]

Not absolutely necessary, as AutoCAD will perform its own garbage collection.

Hm okay, but is there any further action required? Like "empten the garbage" ?

You can force a garbage collection using the AutoLISP gc function, but it is my understanding that AutoCAD will automatically perform a garbage collection periodically.

Looks like its enough to follow this advice:

From what I have read and experienced, you only need to use the vlax-release-object on symbols that were set with vlax-get-object, vlax-create-object, vlax-get-or-create-object or with the method "getinterfaceobject".

Exactly - essentially as I noted earlier, it is generally only considered necessary to release objects outside of the scope of the AutoCAD Object Model.

[QuestionEverything]

Thank you for helping,
This function is no longer mystery for me.