PTHREAD_RWLOCK_INIT(3)    OpenBSD Programmer's Manual   PTHREAD_RWLOCK_INIT(3)

NAME
     pthread_rwlock_init - initialize a read/write lock

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.  Oth-
     erwise an error number will be returned to indicate the error.

SEE ALSO
     pthread_rwlock_destroy(3),  pthread_rwlockattr_init(3),  pthread_rwlock-
     attr_setpshared(3)

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

ERRORS
     The pthread_rwlock_init() function will fail if:

     [EAGAIN]      The system lacked the necessary resources (other than memo-
                   ry) 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 ob-
                   ject referenced by lock, a previously initialized but not
                   yet destroyed read/write lock.

     [EINVAL]      The value specified by attr is invalid.

HISTORY
     The pthread_rwlock_init() function first appeared in OpenBSD 2.5.

BUGS
     The PTHREAD_PROCESS_SHARED attribute is not supported.

OpenBSD 2.6                     August 4, 1998                               1
