уничтожить и инициализировать объект атрибутов порождения (РАСШИРЕННОЕ РЕАЛЬНОЕ ВРЕМЯ) (destroy and initialize spawn attributes object (ADVANCED REALTIME))
Пролог (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.
Имя (Name)
posix_spawnattr_destroy, posix_spawnattr_init — destroy and
initialize spawn attributes object (ADVANCED REALTIME)
Синопсис (Synopsis)
#include <spawn.h>
int posix_spawnattr_destroy(posix_spawnattr_t *attr);
int posix_spawnattr_init(posix_spawnattr_t *attr);
Описание (Description)
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. POSIX.1‐2008 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
POSIX.1‐2008. Attributes not defined by POSIX.1‐2008, 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.
Возвращаемое значение (Return value)
Upon successful completion, posix_spawnattr_destroy() and
posix_spawnattr_init() shall return zero; otherwise, an error
number shall be returned to indicate the error.
Ошибки (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.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
These functions are part of the Spawn option and need not be
provided on all implementations.
Обоснование (Rationale)
The original spawn interface proposed in POSIX.1‐2008 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.
Будущие направления (Future directions)
None.
Смотри также (See also)
posix_spawn(3p), posix_spawnattr_getsigdefault(3p),
posix_spawnattr_getflags(3p), posix_spawnattr_getpgroup(3p),
posix_spawnattr_getschedparam(3p),
posix_spawnattr_getschedpolicy(3p),
posix_spawnattr_getsigmask(3p)
The Base Definitions volume of POSIX.1‐2017, spawn.h(0p)
