PTHREAD_SPIN_LOCK(3P)

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.

NAME
pthread_spin_lock, pthread_spin_trylock — lock a spin lock object

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
The pthread_spin_lock() function may fail if:

EDEADLK
    A deadlock condition was detected.

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 POSIX.1-2017, Section 3.291, Priority Inversion.

RATIONALE
If an implementation detects that the value specified by the lock argument to pthread_spin_lock() or pthread_spin_trylock() 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_lock() refers to a spin lock object for which the calling thread already holds the lock, it is recommended that the function should fail and report an [EDEADLK] error.

FUTURE DIRECTIONS
None.

SEE ALSO
pthread_spin_destroy(), pthread_spin_unlock()

The Base Definitions volume of POSIX.1-2017, Section 3.291, Priority Inversion, Section 4.12, Memory Synchronization, <pthread.h>

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 .

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 .