NAME
pthread_spin_lock
pthread_spin_trylock — lock
a spin lock object (ADVANCED REALTIME THREADS)
SYNOPSIS
[THR
SPI]
#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]
- A deadlock condition was detected or 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].
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 (“POSIX.1”), xbd_chap03(7).
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(3), pthread_spin_unlock(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), <pthread.h>
CHANGE HISTORY
First released in Issue 6. Derived from IEEE Std 1003.1j-2000.
In the SYNOPSIS, the inclusion of <sys/types.h> is no longer required.
IEEE Std 1003.1-2001 (“POSIX.1”)/Cor 2-2004, item XSH/TC2/D6/107 is applied, updating the ERRORS section so that the [EDEADLK] error includes detection of a deadlock condition.
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