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. 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.