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.Dd January 22, 2004 .Dt PTHREAD_SPIN_INIT 3 .Os .Sh NAME .Nm pthread_spin_init , pthread_spin_destroy .Nd "initialize or destroy a spin lock" .Sh LIBRARY .Lb libpthread .Sh SYNOPSIS n pthread.h .Ft int .Fn pthread_spin_init "pthread_spinlock_t *lock" "int pshared" .Ft int .Fn pthread_spin_destroy "pthread_spinlock_t *lock" .Sh DESCRIPTION The .Fn pthread_spin_init function will initialize .Fa lock to an unlocked state and allocate any resources necessary to begin using it. If .Fa pshared is set to .Dv 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 .Fa lock resides, can use .Fa lock . If it is set to .Dv PTHREAD_PROCESS_PRIVATE , it can only be used by threads within the same process.
p The .Fn pthread_spin_destroy function will destroy .Fa lock and release any resources that may have been allocated on its behalf. .Sh RETURN VALUES If successful, both .Fn pthread_spin_init and .Fn pthread_spin_destroy will return zero. Otherwise, an error number will be returned to indicate the error.
p Neither of these functions will return .Er EINTR . .Sh ERRORS The .Fn pthread_spin_init and .Fn pthread_spin_destroy functions will fail if: l -tag -width Er t Bq Er EBUSY An attempt to initialize or destroy .Fa lock while it is in use. t Bq Er EINVAL The value specified by .Fa lock is invalid. .El
p The .Fn pthread_spin_init function will fail if: l -tag -width Er t Bq Er EAGAIN Insufficient resources, other than memory, to initialize .Fa lock . t Bq Er ENOMEM Insufficient memory to initialize .Fa lock . .El .Sh SEE ALSO .Xr pthread_spin_lock 3 , .Xr pthread_spin_unlock 3 .Sh HISTORY The .Fn pthread_spin_init and .Fn pthread_spin_destroy functions first appeared in .Lb libkse in .Fx 5.2 , and in .Lb libthr in .Fx 5.3 . .Sh BUGS The implementation of .Fn pthread_spin_init does not fully conform to .St -p1003.2 because the .Fa pshared argument is ignored in .Lb libthr , and in .Lb libkse if any value other than .Dv PTHREAD_PROCESSES_PRIVATE is specified, it returns .Er EINVAL .