Several Debian based distributions were recently found
to have omitted a kernel configuration option that had
the effect of rendering /proc/#/stat and /proc/#/wchan
useless for providing any 'sleeping in function' info.
That problem also prompted a reevaluation of the whole
approach to wchan matters which had grown increasingly
complex as our library evolved over the last 13 years.
The net result was a decision to rely on /proc/#/wchan
which arrived along with the 2.5 kernel. This then let
us vastly simplify the internal code plus the external
interface which will benefit both the top and ps pgms.
Reference(s):
http://www.freelists.org/post/procps/WCHAN,11https://lkml.org/lkml/2008/11/6/12https://bugs.debian.org/711592
Signed-off-by: Jim Warner <james.warner@comcast.net>
procps automake defines restrict which means the binaries for procps
binaries compile. However external programs may not of defined
restrict which means they will not complie if they include files found
in /usr/include/proc.
Includes from libc6 use __restrict and if is good enough for
them, its good enough for us.
A callback provision in the form of xalloc_err_handler
(of type message_fn) was added to the alloc module.
This change allowed a program like top, who alters the
termios structure, to override the default fprint(stderr...)
behavior in the event of an error.
The new function xstrdup was also added for symmetry.
