WG15 Defect Report Ref: 9945-1-amd1-07
Topic: sigaction

This is an approved interpretation of 9945-1-amd1-1993.


Last update: 1997-05-20

								9945-1-amd1-93  #7


	Topic:                sigaction
	Relevant Sections: Page 72 lines 915-923

Defect Report:

	From: ajosey@xopen.org (Andrew Josey)
	Date: Thu Mar  7 15:18:23 GMT 1996

(This request raised on Behalf of the X/Open Base working group)

ISO/IEC 9945-1-amd1-1993 	Section Page 72 lines 915-923
describes what happens if a signal is pending that
is dispatched at a time when a signal handler was in place 
expecting three arguments.

This section does not describe what happens to the second and
third arguments of a signal handler that catches a signal
that was dispatched when a signal handler expecting one argument
was installed. What is the conformant behaviour in this case?

Interpretation response

The question as asked has some ambiguity and would have different answers based
up which question is meant

If a signal is generated during a time that SA_SIGINFO is set in sa_flags,
sigqueue can pass a si_value and the signal has an associated si_code.  If
sigaction is called with sa_flags clear, then the standard is clear that 'the
signal-catching function shall be invoked with only a single argument' (pg 72
line 917): the signo is delivered.

If a signal is generated during a time that SA_SIGINFO is cleared in sa_flags,
sigqueue still has a si_value and the associated si_code.  If sigaction is then
called before delivery with sa_flags set, then the standard is clear that 'The
application specified value shall be passed to the signal-catching function...'
(pg 72 line 922-923).   

Forwarded to Interpretations group: Mar 7 1996
Finalised: Apr 9 1996