freebsd man page for pthread_rwlock_init

PTHREAD_RWLOCK_INIT(3)					   BSD Library Functions Manual 				    PTHREAD_RWLOCK_INIT(3)

NAME
     pthread_rwlock_init -- initialize a read/write lock

LIBRARY
     POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS
     #include <pthread.h>

     int
     pthread_rwlock_init(pthread_rwlock_t *lock, const pthread_rwlockattr_t *attr);

DESCRIPTION
     The pthread_rwlock_init() function is used to initialize a read/write lock, with attributes specified by attr.  If attr is NULL, the default
     read/write lock attributes are used.

     The results of calling pthread_rwlock_init() with an already initialized lock are undefined.

RETURN VALUES
     If successful, the pthread_rwlock_init() function will return zero.  Otherwise an error number will be returned to indicate the error.

ERRORS
     The pthread_rwlock_init() function will fail if:

     [EAGAIN]		The system lacked the necessary resources (other than memory) to initialize the lock.

     [ENOMEM]		Insufficient memory exists to initialize the lock.

     [EPERM]		The caller does not have sufficient privilege to perform the operation.

     The pthread_rwlock_init() function may fail if:

     [EBUSY]		The system has detected an attempt to re-initialize the object referenced by lock, a previously initialized but not yet
			destroyed read/write lock.

     [EINVAL]		The value specified by attr is invalid.

SEE ALSO
     pthread_rwlock_destroy(3), pthread_rwlockattr_init(3), pthread_rwlockattr_setpshared(3)

STANDARDS
     The pthread_rwlock_init() function is expected to conform to Version 2 of the Single UNIX Specification (``SUSv2'').

HISTORY
     The pthread_rwlock_init() function first appeared in FreeBSD 3.0.

BUGS
     The PTHREAD_PROCESS_SHARED attribute is not supported.

BSD
								  August 4, 1998							       BSD