Originální popis anglicky:
posix_spawnattr_destroy, posix_spawnattr_init - destroy and initialize spawn
attributes object (
ADVANCED REALTIME)
Návod, kniha: POSIX Programmer's Manual
#include <spawn.h>
int posix_spawnattr_destroy(posix_spawnattr_t *
attr);
int posix_spawnattr_init(posix_spawnattr_t *
attr);
The
posix_spawnattr_destroy() function shall destroy a spawn attributes
object. A destroyed
attr attributes object can be reinitialized using
posix_spawnattr_init(); the results of otherwise referencing the object
after it has been destroyed are undefined. An implementation may cause
posix_spawnattr_destroy() to set the object referenced by
attr
to an invalid value.
The
posix_spawnattr_init() function shall initialize a spawn attributes
object
attr with the default value for all of the individual attributes
used by the implementation. Results are undefined if
posix_spawnattr_init() is called specifying an already initialized
attr attributes object.
A spawn attributes object is of type
posix_spawnattr_t (defined in
<spawn.h>) and is used to specify the inheritance of process
attributes across a spawn operation. IEEE Std 1003.1-2001 does
not define comparison or assignment operators for the type
posix_spawnattr_t.
Each implementation shall document the individual attributes it uses and their
default values unless these values are defined by
IEEE Std 1003.1-2001. Attributes not defined by
IEEE Std 1003.1-2001, their default values, and the names of the
associated functions to get and set those attribute values are
implementation-defined.
The resulting spawn attributes object (possibly modified by setting individual
attribute values), is used to modify the behavior of
posix_spawn() or
posix_spawnp(). After a spawn attributes object has been used to spawn
a process by a call to a
posix_spawn() or
posix_spawnp(), any
function affecting the attributes object (including destruction) shall not
affect any process that has been spawned in this way.
Upon successful completion,
posix_spawnattr_destroy() and
posix_spawnattr_init() shall return zero; otherwise, an error number
shall be returned to indicate the error.
The
posix_spawnattr_init() function shall fail if:
- ENOMEM
- Insufficient memory exists to initialize the spawn
attributes object.
The
posix_spawnattr_destroy() function may fail if:
- EINVAL
- The value specified by attr is invalid.
The following sections are informative.
None.
These functions are part of the Spawn option and need not be provided on all
implementations.
The original spawn interface proposed in IEEE Std 1003.1-2001
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
spawn-schedparam and
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
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.
None.
posix_spawn() ,
posix_spawnattr_getsigdefault() ,
posix_spawnattr_getflags() ,
posix_spawnattr_getpgroup() ,
posix_spawnattr_getschedparam() ,
posix_spawnattr_getschedpolicy() ,
posix_spawnattr_getsigmask()
,
posix_spawnattr_setsigdefault() ,
posix_spawnattr_setflags() ,
posix_spawnattr_setpgroup() ,
posix_spawnattr_setsigmask() ,
posix_spawnattr_setschedpolicy() ,
posix_spawnattr_setschedparam() ,
posix_spawnp() , the Base
Definitions volume of IEEE Std 1003.1-2001,
<spawn.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 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
.
