Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [PATCH 01/14] tools lib traceevent: Get rid of malloc_or_die() in show_error() | Date | Tue, 10 Dec 2013 11:03:44 +0900 |
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On Mon, 9 Dec 2013 14:23:50 -0500, Steven Rostedt wrote: > On Mon, 9 Dec 2013 16:14:39 -0300 > Arnaldo Carvalho de Melo <acme@ghostprotocols.net> wrote: > >> Em Mon, Dec 09, 2013 at 02:03:42PM -0500, Steven Rostedt escreveu: >> > On Mon, 9 Dec 2013 15:30:09 -0300 >> > Arnaldo Carvalho de Melo <acme@ghostprotocols.net> wrote: >> > >> > >> > > > + error = malloc(MAX_ERR_STR_SIZE); >> > > > + if (error == NULL) { >> > > > + /* no memory */ >> > > > + *error_str = "failed to allocate memory"; >> > > > + return; >> > > >> > > Can *error_str point to either malloc'ed or constant strings? Who >> > > releases the allocated memory? >> > > >> > >> > Good question. Perhaps we should have a flag that states if the string >> > is allocated or not. Or better yet, since the only reason it would be >> > pointing to a static string is if the string for error_str itself >> > failed to allocate. Then we could use a string within pevent for it: >> > >> > static char *pevent_failed_error_alloc = "failed to allocate memory"; >> > >> > Then in the freeing of error str: >> > >> > void pevent_free_error_str(error_str) >> > { >> > if (error_str != pevent_failed_error_alloc) >> > free(error_str); >> > } >> >> That is a possibility, yes, then any other routine that works in such a >> way could check against this string, but what is wrong with returning a >> value to that function and checking against < 0? > > Then everyone has to check if show_error() failed. Then report a bug if > it did. Egad, then we need to check if that error function failed, and > then that one and that one and that one :-)
What about returning error code rather than string? This way we won't worry about the allocation of the error string itself.
But the downside of it is loosing a positional info of the error. Hmm.. what about using a static buffer in pevent for it then?
Thanks, Namhyung
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