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'\" et
.TH POSIX_SPAWNATTR_DESTROY "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
posix_spawnattr_destroy,
posix_spawnattr_init
\(em destroy and initialize spawn attributes object
(\fBADVANCED REALTIME\fP)
.SH SYNOPSIS
.LP
.nf
#include <spawn.h>
.P
int posix_spawnattr_destroy(posix_spawnattr_t *\fIattr\fP);
int posix_spawnattr_init(posix_spawnattr_t *\fIattr\fP);
.fi
.SH DESCRIPTION
The
\fIposix_spawnattr_destroy\fR()
function shall destroy a spawn attributes object. A destroyed
.IR attr
attributes object can be reinitialized using
\fIposix_spawnattr_init\fR();
the results of otherwise referencing the object after it
has been destroyed are undefined. An implementation may cause
\fIposix_spawnattr_destroy\fR()
to set the object referenced by
.IR attr
to an invalid value.
.P
The
\fIposix_spawnattr_init\fR()
function shall initialize a spawn attributes object
.IR attr
with the default value for all of the individual attributes used by the
implementation. Results are undefined if
\fIposix_spawnattr_init\fR()
is called specifying an already initialized
.IR attr
attributes object.
.P
A spawn attributes object is of type
.BR posix_spawnattr_t
(defined in
.IR <spawn.h> )
and is used to specify the inheritance of process attributes across a
spawn operation. POSIX.1\(hy2008 does not define comparison or assignment
operators for the type
.BR posix_spawnattr_t .
.P
Each implementation shall document the individual attributes it uses
and their default values unless these values are defined by POSIX.1\(hy2008.
Attributes not defined by POSIX.1\(hy2008, their default values, and the names of
the associated functions to get and set those attribute values are
implementation-defined.
.P
The resulting spawn attributes object (possibly modified by setting
individual attribute values), is used to modify the behavior of
\fIposix_spawn\fR()
or
\fIposix_spawnp\fR().
After a spawn attributes object has been used to spawn a process by a
call to a
\fIposix_spawn\fR()
or
\fIposix_spawnp\fR(),
any function affecting the attributes object (including destruction)
shall not affect any process that has been spawned in this way.
.SH "RETURN VALUE"
Upon successful completion,
\fIposix_spawnattr_destroy\fR()
and
\fIposix_spawnattr_init\fR()
shall return zero; otherwise, an error number shall be returned to
indicate the error.
.SH ERRORS
The
\fIposix_spawnattr_init\fR()
function shall fail if:
.TP
.BR ENOMEM
Insufficient memory exists to initialize the spawn attributes object.
.P
The
\fIposix_spawnattr_destroy\fR()
function may fail if:
.TP
.BR EINVAL
The value specified by attr is invalid.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
These functions are part of the Spawn option and need not be
provided on all implementations.
.SH RATIONALE
The original spawn interface proposed in POSIX.1\(hy2008 defined the attributes
that specify the inheritance of process attributes across a spawn
operation as a structure. In order to be able to separate optional
individual attributes under their appropriate options (that is, the
.IR spawn-schedparam
and
.IR spawn-schedpolicy
attributes depending upon the Process Scheduling option), and also for
extensibility and consistency with the newer POSIX interfaces, the
attributes interface has been changed to an opaque data type. This
interface now consists of the type
.BR posix_spawnattr_t ,
representing a spawn attributes object, together with associated
functions to initialize or destroy the attributes object, and to set or
get each individual attribute. Although the new object-oriented
interface is more verbose than the original structure, it is simple to
use, more extensible, and easy to implement.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.ad l
.IR "\fIposix_spawn\fR\^(\|)",
.IR "\fIposix_spawnattr_getsigdefault\fR\^(\|)",
.IR "\fIposix_spawnattr_getflags\fR\^(\|)",
.IR "\fIposix_spawnattr_getpgroup\fR\^(\|)",
.IR "\fIposix_spawnattr_getschedparam\fR\^(\|)",
.IR "\fIposix_spawnattr_getschedpolicy\fR\^(\|)",
.IR "\fIposix_spawnattr_getsigmask\fR\^(\|)"
.ad b
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<spawn.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
|
