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From: cgd@eden.CS.Berkeley.EDU (Chris G. Demetriou)
Newsgroups: comp.os.386bsd.bugs
Subject: Re: cvs 1.3 bugfix
Date: 4 Mar 93 17:08:21
Organization: Kernel Hackers 'r' Us
Lines: 100
Message-ID: <CGD.93Mar4170821@eden.CS.Berkeley.EDU>
References: <RICH.93Mar3114046@omicron.Rice.edu>
<SOMMERFELD.93Mar3180839@blatt.apollo.hp.com>
<RICH.93Mar3233616@omicron.Rice.edu>
NNTP-Posting-Host: eden.cs.berkeley.edu
In-reply-to: rich@Rice.edu's message of Thu, 4 Mar 1993 05:36:16 GMT
In article <RICH.93Mar3233616@omicron.Rice.edu> rich@Rice.edu (Richard Murphey) writes:
>Yep, the posix spec claims sigismember() should return -1 if signo is
>out of range. Perhaps this would be sufficient. Rich
actually, i just got into a too- long and heated discussion w/
keith bostic about this...
enclosed at the bottom is the transcribed section from posix.
it turns out that the macro is fine just the way it was;
the error (in input) *does not* _have_ to be detected by the
function, but if it is, -1 should be returned, and errno
should be set.
the only way to do this w/a non-contiguous signal numbering space
is a (hacked!) function. (note that when _POSIX_SOURCE is defined,
the 386bsd signal numbers *are* non-contiguous...
also note that your macro doesn't set errno appropriately...
Keith made a convincing argument for the macro as-it-stands --
if a programmer wants to rely on a contiguous signal numbering
space, or do something otherwise stupid, it's their fault, and
their problem.
CVS should be fixed...
chris
============= section 3.3.3 of posix.1 (all typos are mine... 8-):
3.3.3 Manipulate Signal Sets
Functions sigemptyset(), sigfillset(), sigaddset(), sigdelset(), sigismember()
3.3.3.1 Synopsis
#include <signal.h>
int sigemptyset(sigset_t *set);
int sigfillset(sigset_t *set);
int sigaddset(sigset_t *set, int signo);
int sigdelset(sigset_t *set, int signo);
int sigismember(const sigset_t *set, int signo);
3.3.3.2 Description
The sigsetops primitives manipulate sets of signals. They operate on data
objects addressable by the application, not on any set of signals known
to the system, such as the set blocked from delivery to a process or
the set pending for a process (see 3.3.1).
The sigemptyset() function initializes the signal set pointed to by the
argument _set_, such that all signals defined in this part of ISO/IEC 9945
are excluded.
The sigfillset() function initializes the signal set pointed to by the
argument _set_, such that all signals defined in this part of ISO/IEC 9945
are included.
Applications shall call either sigemptyset() or sigfillset() at least
once for each object of type sigset_t prior to any use of that object.
If such an object is not initialized in this way, but is nonetheless
supplied as an argument to any of the sigaddset(), sigdelset(),
sigismember(), sigaction(), sigprocmask(), sigpending(), or
sigsuspend() functions, the results are undefined.
The sigaddset() and sigdelset() functions respectively add or delete
the individual signal specified by the value of the argument _signo_ to or
from the signal set pointed to by the argument _set_.
The sigismember() function tests whether the signal specified by the value
of the argument _signo_ is a member of the set pointed to by the argument
_set_.
3.3.3.3 Returns
Upon successful completion, the sigismember() function returns a value of
one if the specified signal is a member of a specified set, or a value
of zero if it is not. Upon successful completion, the other functions
return a value of zero. For all of the above functions, if an error is
detected, a value of -1 is returned, and _errno_ is set to indicate the
error.
3.3.3.4 Errors
For each of the following conditions, if the condition is detected, the
sigaddset(), sigdelset(), and sigismember() functions shall return -1
and set _errno_ to the corresponding value:
[ EINVAL ] The value of the _signo_ argument is an invalid
or unsupported signal number.
3.3.3.5 Cross-References
sigaction(), 3.3.4; <signal.h>, 3.3.1; sigpending(), 3.3.6; sigprocmask(),
3.3.5; sigsuspend(), 3.3.7.
--
Chris G. Demetriou cgd@cs.berkeley.edu
MENTALLY CONTAMINATED and proud of it!