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Not many changes here to < code class = "filename" > cstdlib< / code > . You should note that the
< code class = "function" > abort()< / code > 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 < code class = "function" > atexit()< / code >
don't get called either, so you can forget about that
possibility, too.)
< / p > < p >
The good old < code class = "function" > exit()< / code > function can be a bit
funky, too, until you look closer. Basically, three points to
remember are:
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< / p > < div class = "orderedlist" > < ol class = "orderedlist" type = "1" > < li class = "listitem" > < p >
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Static objects are destroyed in reverse order of their creation.
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< / p > < / li > < li class = "listitem" > < p >
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Functions registered with < code class = "function" > atexit()< / code > are called in
reverse order of registration, once per registration call.
(This isn't actually new.)
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< / p > < / li > < li class = "listitem" > < p >
The previous two actions are < span class = "quote" > “< span class = "quote" > interleaved,< / span > ”< / span > that is,
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given this pseudocode:
< / p > < pre class = "programlisting" >
extern "C or C++" void f1 (void);
extern "C or C++" void f2 (void);
static Thing obj1;
atexit(f1);
static Thing obj2;
atexit(f2);
< / pre > < p >
then at a call of < code class = "function" > exit()< / code > ,
< code class = "varname" > f2< / code > will be called, then
< code class = "varname" > obj2< / code > will be destroyed, then
< code class = "varname" > f1< / code > will be called, and finally
< code class = "varname" > obj1< / code > will be destroyed. If
< code class = "varname" > f1< / code > or < code class = "varname" > f2< / code > allow an
exception to propagate out of them, Bad Things happen.
< / p > < / li > < / ol > < / div > < p >
Note also that < code class = "function" > atexit()< / code > 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 < code class = "function" > xatexit< / code > /< code class = "function" > xexit< / code > combination from < code class = "literal" > libiberty< / code > , which has no such limit.
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