Keywords: ISO C++ , library

Chapter 6. Termination
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## Chapter 6. Termination

## Termination Handlers

Not many changes here to `cstdlib`. You should note that the `abort()` function does not call the destructors of automatic nor static objects, so if you're depending on those to do cleanup, it isn't going to happen. (The functions registered with `atexit()` don't get called either, so you can forget about that possibility, too.)

The good old `exit()` function can be a bit funky, too, until you look closer. Basically, three points to remember are:

1. Static objects are destroyed in reverse order of their creation.

2. Functions registered with `atexit()` are called in reverse order of registration, once per registration call. (This isn't actually new.)

3. The previous two actions are “interleaved,” that is, given this pseudocode:

         extern "C or C++" void  f1 (void);
         extern "C or C++" void  f2 (void);

         static Thing obj1;
         atexit(f1);
         static Thing obj2;
         atexit(f2);

   then at a call of `exit()`, `f2` will be called, then `obj2` will be destroyed, then `f1` will be called, and finally `obj1` will be destroyed. If `f1` or `f2` allow an exception to propagate out of them, Bad Things happen.

Note also that `atexit()` is only required to store 32 functions, and the compiler/library might already be using some of those slots. If you think you may run out, we recommend using the `xatexit`/`xexit` combination from `libiberty`, which has no such limit.

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