NAME
pthread_spin_init
,
pthread_spin_destroy
—
initialize or destroy a spin
lock
LIBRARY
library “libpthread”
SYNOPSIS
#include
<pthread.h>
int
pthread_spin_init
(pthread_spinlock_t
*lock, int
pshared);
int
pthread_spin_destroy
(pthread_spinlock_t
*lock);
DESCRIPTION
Thepthread_spin_init
()
function will initialize lock to an unlocked state and
allocate any resources necessary to begin using it. If
pshared is set to
PTHREAD_PROCESS_SHARED
, any thread, whether belonging
to the process in which the spinlock was created or not, that has access to
the memory area where lock resides, can use
lock. If it is set to
PTHREAD_PROCESS_PRIVATE
, it can only be used by
threads within the same process.
The
pthread_spin_destroy
()
function will destroy lock and release any resources
that may have been allocated on its behalf.
RETURN VALUES
If successful, both pthread_spin_init
()
and pthread_spin_destroy
() will return zero.
Otherwise, an error number will be returned to indicate the error.
Neither of these functions will return
EINTR
.
ERRORS
The pthread_spin_init
() and
pthread_spin_destroy
() functions will fail if:
- [
EBUSY
] - An attempt to initialize or destroy lock while it is in use.
- [
EINVAL
] - The value specified by lock is invalid.
The pthread_spin_init
() function will fail
if:
- [
EAGAIN
] - Insufficient resources, other than memory, to initialize lock.
- [
ENOMEM
] - Insufficient memory to initialize lock.
SEE ALSO
BUGS
The implementation of pthread_spin_init
()
does not fully conform to IEEE Std 1003.2
(“POSIX.2”) because the pshared
argument is ignored; if any value other than
PTHREAD_PROCESS_PRIVATE
is specified, it returns
EINVAL
.