FreeBSD manual

download PDF document: pthread_rwlock_init.3.pdf

PTHREAD_RWLOCK_INIT(3) FreeBSD Library Functions Manual
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 *restrict lock, const pthread_rwlockattr_t *restrict 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.
FreeBSD 14.0-RELEASE-p11 August 17, 2018 FreeBSD 14.0-RELEASE-p11