уничтожить или инициализировать объект блокировки вращения (destroy or initialize a spin lock object)
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)
pthread_spin_destroy, pthread_spin_init — destroy or initialize a
spin lock object
Синопсис (Synopsis)
#include <pthread.h>
int pthread_spin_destroy(pthread_spinlock_t *lock);
int pthread_spin_init(pthread_spinlock_t *lock, int pshared);
Описание (Description)
The pthread_spin_destroy() function shall destroy the spin lock
referenced by lock and release any resources used by the lock.
The effect of subsequent use of the lock is undefined until the
lock is reinitialized by another call to pthread_spin_init().
The results are undefined if pthread_spin_destroy() is called
when a thread holds the lock, or if this function is called with
an uninitialized thread spin lock.
The pthread_spin_init() function shall allocate any resources
required to use the spin lock referenced by lock and initialize
the lock to an unlocked state.
If the Thread Process-Shared Synchronization option is supported
and the value of pshared is PTHREAD_PROCESS_SHARED, the
implementation shall permit the spin lock to be operated upon by
any thread that has access to the memory where the spin lock is
allocated, even if it is allocated in memory that is shared by
multiple processes.
See Section 2.9.9, Synchronization Object Copies and Alternative
Mappings for further requirements.
The results are undefined if pthread_spin_init() is called
specifying an already initialized spin lock. The results are
undefined if a spin lock is used without first being initialized.
If the pthread_spin_init() function fails, the lock is not
initialized and the contents of lock are undefined.
Only the object referenced by lock may be used for performing
synchronization.
The result of referring to copies of that object in calls to
pthread_spin_destroy(), pthread_spin_lock(),
pthread_spin_trylock(), or pthread_spin_unlock() is undefined.
Возвращаемое значение (Return value)
Upon successful completion, these functions shall return zero;
otherwise, an error number shall be returned to indicate the
error.
Ошибки (Error)
The pthread_spin_init() function shall fail if:
EAGAIN The system lacks the necessary resources to initialize
another spin lock.
ENOMEM Insufficient memory exists to initialize the lock.
These functions shall not return an error code of [EINTR].
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
If an implementation detects that the value specified by the lock
argument to pthread_spin_destroy() does not refer to an
initialized spin lock object, it is recommended that the function
should fail and report an [EINVAL] error.
If an implementation detects that the value specified by the lock
argument to pthread_spin_destroy() or pthread_spin_init() refers
to a locked spin lock object, or detects that the value specified
by the lock argument to pthread_spin_init() refers to an already
initialized spin lock object, it is recommended that the function
should fail and report an [EBUSY] error.
Будущие направления (Future directions)
None.
Смотри также (See also)
pthread_spin_lock(3p), pthread_spin_unlock(3p)
The Base Definitions volume of POSIX.1‐2017, pthread.h(0p)
