Hi Narendra,
i got this, take a look at:
here, at this point..:
That "handlePageException" method has teh following code:
It means that...if there is some error regarding tag process, the pageContext attribute is release(==null) - PageContext.release());
And, as you said, when the Classic tags are going to GC, they call TagSupport.release();
I think that�s it!