NAME
pthread_spin_lock, pthread_spin_trylock - lock a spin lock object
(ADVANCED REALTIME THREADS)
SYNOPSIS
#include <pthread.h>
int pthread_spin_lock(pthread_spinlock_t *lock);
int pthread_spin_trylock(pthread_spinlock_t *lock);
DESCRIPTION
The pthread_spin_lock() function shall lock the spin lock referenced by
lock. The calling thread shall acquire the lock if it is not held by
another thread. Otherwise, the thread shall spin (that is, shall not
return from the pthread_spin_lock() call) until the lock becomes
available. The results are undefined if the calling thread holds the
lock at the time the call is made. The pthread_spin_trylock() function
shall lock the spin lock referenced by lock if it is not held by any
thread. Otherwise, the function shall fail.
The results are undefined if any of these functions is called with an
uninitialized spin lock.
RETURN VALUE
Upon successful completion, these functions shall return zero;
otherwise, an error number shall be returned to indicate the error.
ERRORS
These functions may fail if:
EINVAL The value specified by lock does not refer to an initialized
spin lock object.
The pthread_spin_lock() function may fail if:
EDEADLK
The calling thread already holds the lock.
The pthread_spin_trylock() function shall fail if:
EBUSY A thread currently holds the lock.
These functions shall not return an error code of [EINTR].
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
Applications using this function may be subject to priority inversion,
as discussed in the Base Definitions volume of IEEE Std 1003.1-2001,
Section 3.285, Priority Inversion.
The pthread_spin_lock() and pthread_spin_trylock() functions are part
of the Spin Locks option and need not be provided on all
implementations.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_spin_destroy() , pthread_spin_unlock() , the Base Definitions
volume of IEEE Std 1003.1-2001, <pthread.h>
COPYRIGHT
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 .