TITLE: registering functions with atexit

(Newsgroup: comp.std.c++, 1 Dec 98)


ALEXANDRESCU: "Andrei Alexandrescu" <alexandrescua@micromodeling.com>

>The question is: say I register function
>
>void foo();
>
>to be called by atexit. From within foo(), I call atexit() again and
>register the function:
>
>void bar();
>
>to be called. Will be bar() called?


Clamage: Steve Clamage (stephen.clamage@sun.com)

Neither the C nor the C++ standards define what happens
after you register bar(). In fact, each is self-contradictory
on the matter!

The question was put to the C committee at their meeting last
month, and I have been told informally that the next C
standard will make the result undefined.

The C++ committee has the question on their list of potential
Defect Reports, and has yet to make a decision (on this or on
any other DR -- it's too soon to consider them). I expect
the C++ committee to declare the behavior to be undefined.

In the mean time, I know of at least one implementation that
crashes if you attempt to register a function with atexit
once exit processing has begun. So don't do it.