Re: xmalloc

Roland Pibinger wrote:
On Sat, 23 Jun 2007 16:30:12 -0400, Eric Sosman wrote:
Not all that strange. Half the programmers in the world
are below-average.

which is at least half-true.

But if you follow Malcolm's Maxims, even the above-average
programmers will be helpless. Programs that deal with malloc()
failure in a significant way may be a minority, but those that
do it *need* to to do it. Malcolm argues, in essence, that
such programs should not be written in C.

The discussion basically boils down to one question: Is OOM an error
that reasonably can and should be handled by the application or is it
a fatal error? The 'fatal error' advocates have already shown how they tackle the
problem. Now it's time for the other camp to demonstrate how OOM can
be consistently _handled_ throughout the program ('return NULL;' is
not enough).

Already mentioned a few times in this thread:

buff = malloc(image_size);
if (buff == NULL) {
fprintf (stderr, "Image too large (%lu) to paste\n",
(unsigned long)image_size);
return;
}
/* read image into buff, insert in current document */

Here's another I think has been referred to:

must_have_mem = malloc(how_much);
if (must_have_mem == NULL) {
fprintf (stderr, "Out of memory; shutting down\n");
save_snapshot(snapshot_file);
exit (EXIT_FAILURE);
}
/* store "must have" data in allocated memory */

And here's still another (I don't remember whether it's
cropped up in this thread yet):

void *getmem(size_t bytes) {
void *new = malloc(bytes);
if (new == NULL && bytes > 0) {
fprintf (stderr, "Failed to allocate %lu bytes\n",
(unsigned long)bytes);
free (emergency_stash);
emergency_stash = NULL;
new = malloc(bytes);
if (new == NULL) {
fprintf (stderr, "You were warned ...!\n");
exit (EXIT_FAILURE);
}
fprintf (stderr, "Running on fumes: save your work "
"and exit soon!\n");
}
return NULL;
}

Even if out-of-memory is a "fatal error," it does not follow
that the program should have no opportunity to "die with dignity."
Have you made a will, Roland? If so, should the fact that many
people die intestate invalidate your will? If not, I certainly
don't want your intestacy to invalidate my will!

--
Eric Sosman
esosman@xxxxxxxxxxxxxxxxxxx
.

Relevant Pages

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