PTHREAD_RWLOCK_INIT(3) BSD Library Functions Manual PTHREAD_RWLOCK_INIT(3)NAMEpthread_rwlock_init — initialize a read/write lock
SYNOPSIS
#include <pthread.h>
int
pthread_rwlock_init(pthread_rwlock_t *restrict rwlock,
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. Oth‐
erwise, an error number will be returned to indicate the error.
SEE ALSOpthread_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”).
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 per‐
form the operation.
The pthread_rwlock_init() function may fail if:
[EBUSY] The system has detected an attempt to re-initialize
the object referenced by rwlock, a previously initial‐
ized but not yet destroyed read/write lock.
[EINVAL] The value specified by attr is invalid.
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
